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Aluminij i njegove legure nalaze mnoge primjene u strojarstvu zbog svojih prikladnih svojstava kao što su povoljna specifična čvrstoća i korozijska postojanost. Aluminij se podvrguje različitim tehnologijama obrade kako bi dobili bolja svojstva te prilagodili materijal okolišu u kojem će biti eksploatiran. Materijali u eksploataciji podvrgnuti su različitim vrstama trošenja, a jedno od njih je i erozijsko trošenje. U ovom radu ispitani su uzorci aluminija toplo valjanog, hladno kovanog i uzorci nastali kutnom ekstruzijom u uvjetima erozijskog trošenja te su na kraju izneseni zaključci. Aluminum and its alloys find many applications in mechanical engineering due to their suitable properties such as favorable specific strength and corrosion resistance. Aluminum is subjected to different processing technologies in order to obtain better properties and adapt the material to the environment in which it will be exploited. Materials in exploitation are subjected to different types of wear, one of which is erosion wear. In this paper, samples of hot-rolled, cold-forged aluminum and samples created by angular extrusion under conditions of erosion wear were tested, and conclusions were presented at the end.

Ovaj diplomski rad koncipiran je tako da se je konstruirala vlastita konstrukcija hibridnog okvira bicikla s osnovnim dimenzijama baziranim na opsežnom istraživanju izvora. Na samom početku objašnjene su glavne razlike između bicikala, te su pobrojane glavne vrste okvira bicikla danas u uporabi. Vlastitim dizajnom pojedinih oblika cijevi okvira, došlo se do dva finalna modela koja se geometrijom temelje na osnovnom štapnom modelu/konceptu. U središnjem dijelu razmatrale su se analize konačnim elementima s obzirom na tri najčešća materijala korištena pri izradi bicikala. Slučajevi opterećenja u tim analizama izvedeni su tako da se čim više pokušaju približiti stvarnim eksploatacijskim uvjetima okvira bicikla tijekom vožnje. Dobivenim rezultatima odabran je najadekvatniji materijal koji se je zatim primijenio na numeričke analize vlastita dva dizajna okvira, pod već spomenutim opterećenjima. Na kraju je odabran i objašnjen superiorniji okvir hibridnog bicikla preko rezultata numeričkih analiza. This master thesis is based on idea of constructing a new type of hybrid bicycle frame with basic dimensions acknowledged from an extensive research of many sources. At the very beginning, the main differences between bicycles are explained. After that, some of the main types of bicycle frames in use today are listed. With perception of general geometry of concept model, two new bicycle frames were constructed. There are small differences between their design but the main change are shapes and cross sections of tubes. In the central part, few finite element analysis were conducted with usage of the three most common materials used in the bicycles manufacturing. The load cases in these analysis were performed to simulate actual operating conditions of the bicycle frame during riding. Based on the obtained results, the most adequate material was selected and then was applied to the numerical analysis of two frame designs, under the certain load cases. Finally, a superior hybrid bike frame was selected and explained with brief conclusion based on FEA analysis.

Tema ovog diplomskog bila je proučiti utjecaj alata na mehanička svojstva zavarenog spoja kod točkastog zavarivanja trenjem rotirajućim alatom. U prvom dijelu rada opisan je postupak zavarivanja trenjem rotirajućim alatom, s time da je stavljen fokus na točkasto zavarivanje trenjem rotirajućim alatom. Ukratko je opisana povijest postupka, opisane su faze postupka, utjecajni čimbenici, prednosti i nedostaci. Navedeni su materijali koji se mogu zavarivati točkastim zavarivanjem trenjem rotirajućim alatom te su navedeni primjeri iz prakse gdje se koristi navedena vrsta zavarivanja. U drugom dijelu diplomskog rada provedeno je točkasto zavarivanje trenjem rotirajućim alatom na limovima od aluminijeve legure. Prilikom zavarivanja korištena su 2 tipa alata za zavarivanje te su mijenjane brzine rotacije alata i vrijeme trajanja procesa zavarivanja. Limovi koji su zavareni su podvrgnuti smičnom ispitivanju te je analiziran rezultat ispitivanja. Na kraju rada donesen je zaključak o utjecaju alata na mehanička svojstva zavarenog spoja. The topic of this thesis was to study the influence of tool on the mechanical properties of the welded joint during the friction stir welding. The first part of this master's thesis presents the friction welding procedure with a rotating tool, with the main focus being on spot welding with a rotating friction tool. There can be found a short procedure history brief, all stages of the procedure, influencing factors, advantages and disadvantages. The materials that can be welded by friction stir spot welding with a rotating tool are listed, and also examples from practice were mentioned. In the second part of the thesis, spot welding with a friction rotating tool was performed on aluminum sheets. During welding, 2 types of welding tools were used, and the rotation speeds of the tool and the duration of the welding process were changing. The welded sheets were subjected to a static tensile test and the result was analyzed. Finally, the graduate thesis provides a conclusion about the influence of tool on the mechanical properties of the welded joint.

U teorijskom dijelu rada opisana je podjela aluminijskih legura, njihove karakteristike i problematika zavarljivosti aluminijskih legura s posebnim osvrtom na primjenu aluminijskih legura u brodogradnji. Detaljno je opisan TIG postupak zavarivanja te je objašnjena klasifikacija osnovnih vrsta spojeva koji se primjenjuju pri izradi brodskih konstrukcija. U posljednjem dijelu teorijskog rada dan je pregled pripreme spojeva za zavarivanje aluminijskih legura prema normi HRN EN ISO 9692-3. U eksperimentalnom dijelu rada odabrana je tehnologija zavarivanja aluminijske legure 6082 T6. Strojnom obradom sukladno normi HRN EN ISO 9692-3 pripremljene su dvije cijevi. Provedeno je zavarivanje radnih komanda AC TIG postupkom. Naposljetku su provedena ispitivanja radiografskom metodom, statično-vlačni pokus i ispitivanje savijanjem te je izvršena makroskopska analiza. Na temelju dobivenih rezultata eksperimentalnog rada donesen je zaključak. The theoretical part of this thesis deals with the division of the aluminum alloys, their characteristics and weldability problems, with special reference to the application of aluminum alloys in shipbuilding. The TIG welding process is described in detail. Moreover, the classification of the basic types of joints used in the construction of the ship structures is explained. An overview of the preparation of joints for welding aluminum alloys according to the HRN ISO 9692-3 standard is given in the last part of the theoretical work. In the experimental part the suitable welding technology has been chosen for welding aluminum alloy 6082 T6. Two pipes were prepared by machining accordingly to the HRN ISO 9692-3. Butt welding of pipe was done using the AC TIG technology. Ultimately, tests were carried out using the radiographic method, static tensile test and bending test, along with performing macroscopic analysis. Based on the obtained results of the experimental work, a conclusion was made.

Tema ovog rada je „Analiza utjecaja zaštitnog plina na profil penetracije kod MIG zavarivanja aluminija“ Teorijski dio rada opisuje svojstva aluminija i aluminijskih legura, njihovu primjenu i proizvodnju. Obrađene su tehnologije zavarivanja aluminija te ukratko opisan MIG postupak zavarivanja aluminija. Detaljno su opisani zaštitni plinovi korišteni kod zavarivanja aluminija – argon, helij te plinske mješavine argona i helija. Eksperimentalni dio rada sastoji se od pripreme 3 uzorka aluminijske legure 5083 debljine 10 mm, izvođenja postupka MIG zavarivanja pulsnim lukom i istim parametrima zavarivanja te analizom dobivenih rezultata zavarivanja. Zavareni kutni spojevi podvrgnuti su vizualnoj i penetrantskoj kontroli zavara, izradi makroizbrusaka i mjerenju geometrije. Analizom rezultata ispitivanja utvrđen je utjecaj različitih plinskih mješavina na profil penetracije. Pokazana je razlika u iznosu dubine i obliku penetracije u ovisnosti o postocima argona i helija u zaštitnoj plinskoj mješavini. The topic of this paper is "Analysis of shielding gas influence on penetration profile at MIG welding of aluminum." The theoretical part of the thesis describes the properties of aluminum and aluminum alloys, their applications, and production. Welding technologies of aluminum are discussed, and the MIG welding process of aluminum is described. The protective gases used in aluminum welding - argon, helium, and gas mixtures of argon and helium - are described in detail. The experimental part of the paper consists of preparing three samples of 10 mm thick aluminum alloy 5083, performing the MIG welding process with a spray arc and the same welding parameters and analyzing the obtained welding results. The welded corner joints were visually and penetrant inspected, and macro examinations were done, followed by measuring the geometry. The analysis of the results showed the influence of different shielding gas mixtures on penetration profile. The difference was shown in the depth and shape of the penetration, depending on the percentage of argon and helium in the shielding gas mixture.

Cilj ovoga rada bila je analiza zavarenog spoja legure aluminija oznake EN AW-5083. To je gnječena legura aluminija s najvećim udjelom magnezija kao legirnog elementa. Zavareni spoj izveden je TIG tehnikom spajanja uz prethodno predgrijavanje na 150 °C. U teorijskom dijelu obrađene su vrste aluminija i njegovih legura te načini zavarivanja istih. Objašnjene su moguće pogreške koje se mogu pojaviti tijekom ili nakon zavarivanja. U eksperimentalnom dijelu rada analizirana je makrostruktura zavarenog spoja, te mikrostruktura osnovnog materijala, zone utjecaja topline i metala zavara. Osim toga provedeno je ispitivanje mikrotvrdoće HV0,2, statičko vlačno i savojno ispitivanje. U strukturi nisu uočene nikakve nepravilnosti koje bi negativno utjecale na kvalitetu zavarenog spoja. U odnosu na mikrotvrdoću osnovnog materijala (oko 68 HV0,2), mikrotvrdoća u ZUT-u i metalu zavara je viša za oko 20 %.Vrijednost vlačne čvrstoće u osnovnom materijalu je 330 MPa, a u metalu zavara 280 MPa. Tijekom savojnog ispitivanja do kuta od 180° nisu uočene pukotine u zavarenom spoju. The aim of this work was the analysis of the welded joint of aluminum alloy EN AW-5083. It is a wrought aluminum alloy with the highest proportion of magnesium as an alloying element. The welded joint was made using the TIG joining technique with preheating to 150 °C. In the theoretical part, the types of aluminum and its alloys and methods of welding them are covered. Possible errors that may occur during or after welding are explained. In the experimental part of the work, the macrostructure of the welded joint was analyzed, as well as the microstructure of the base material, the heat-affected zone and the weld metal. In addition, a microhardness test of HV0.2, a tensile and bend test, was performed. No irregularities were observed in the structure that would negatively affect the quality of the welded joint. In relation to the microhardness of the base material (about 68HV0.2), the microhardness in ZUT and weld metal is higher by about 20%. The value of the tensile strength in the base material is 330 MPa, and in the weld metal 280 MPa. During the bending test, no cracks were observed in the welded joint up to an angle of 180°.

Bibliografija: str. 28761-28762.

Tijekom povijesti tenisa, materijali korišteni za izradu reketa značajno su utjecali na performanse igrača. U početku su teniski reketi bili izrađeni od drva i bili su teški, što je igračima otežavalo stvaranje brzine i snage u udarcu. Međutim, s vremenom su se materijali počeli mijenjati kako bi se poboljšale performanse igrača. Prvo se s drvenih reketa prešlo na metalne, posebice aluminijske, a u sedamdesetim godinama prošloga stoljeća pojavljuju se i prvi kompozitni reketi, koji su bili lakši i čvršći. Ovi reketi omogućili su igračima da u udarcima imaju više brzine, snage i preciznosti, što je dovelo do poboljšanja igre i postavljanja novih rekorda. Konačno se pojavljuju i kompozitni reketi ojačani ugljičnim vlaknima koji imaju sve skupa najbolja svojstva i, uz aluminijske rekete, koriste se još danas. Sve u svemu, konstrukcijska rješenja i korišteni materijali zajedno igraju ključnu ulogu u utjecanju na svojstva reketa, što omogućava igračima da pronađu reket koji odgovara njihovom stilu igre i da tako postignu najbolje rezultate na terenu. U završnom radu prikazan je povijesni razvoj konstrukcija i izbora materijala za izradu teniskih reketa. Četiri različite vrste rekreativnih teniskih reketa, tri od proizvođača Babolat i jedan reket tvrtke Wilson, ispitani su u eksperimentalnom dijelu rada. Provedena su laboratorijska ispitivanja savijanjem i analize konstrukcijskih izvedbi te su doneseni odgovarajući zaključci. Throughout the history of tennis, the materials used for making rackets have had significant impact on player performance. In the beginning, tennis rackets were made of wood, and they were heavy, making it difficult for players to generate speed and power in their shots. However, as time went on, materials evolved to improve player performance. Wooden rackets were replaced with metal, specifically aluminium, and in the 1970s, the first composite rackets appeared, which were lighter and stronger. These rackets enabled players to have more speed, power and accuracy in their shots, resulting in better, more beautiful play and the setting of new records. Finally, composite rackets reinforced with carbon fibres emerged, which have the best overall properties and, along with aluminium rackets, are still used today. In conclusion, the construction design and the materials used for making tennis rackets have a significant impact on a racket’s properties. This has allowed players to find rackets that match their playing style, leading to improved performance and results on the court. This Bachelor thesis presents the historical development of constructions and materials selection for tennis rackets. Four different types of recreational tennis rackets, three from Babolat and one from Wilson, were tested in the experimental part of the thesis. Laboratory bending tests and analyses of design were carried out and appropriate conclusions were drawn.

U teorijskom dijelu rada opisane su tehnologije lijevanja aluminijskih legura. U prvom je dijelu opisana legura AlSi12 i utjecaj legirnih elemenata na svojstva aluminijskih legura. Također, navedene su i eventualne greške u odljevcima koje se mogu pojaviti prilikom lijevanja. U eksperimentalnom dijelu rada istraživan je utjecaj orijentacije odljevka u kalupu na pojavu poroznosti skupljanja. Za odabrani su odljevak proračunate i konstruirane dvije varijante horizontalnog i dvije varijante vertikalnog uljevnog sustava. Simulacija lijevanja provedena je u programskom paketu ProCAST, a analizom su iste dana konstrukcijska poboljšanja. Lijevanje odljevaka provedeno je u Laboratoriju za ljevarstvo Fakulteta strojarstva i brodogradnje Sveučilišta u Zagrebu. Odljevci su nakon hlađenja i skrućivanja ispitani radiografskom metodom. Rezultati ispitivanja radiografskom metodom uspoređeni su s rezultatima simulacije. Snimljeni su radiogrami ukazali na pojavu plinske poroznosti i poroznosti skupljanja u svim odljevcima. Najbolja se pokazala varijanta lijevanja s direktnim vertikalnim uljevnim sustavom. In the theoretical part of the thesis, casting technologies for aluminium alloys were described. In the first part, the alloy AlSi12 and the influence of alloying elements on the properties of aluminium alloys were described. In addition, possible defects in castings that may occur during casting were listed. In the experimental part of the work, the influence of the casting orientation in the mould on the occurrence of shrinkage porosity was investigated. Two variants of the horizontal and two variants of the vertical gating system were calculated and designed for the selected casting. The casting simulation was performed using the ProCAST software package and design improvements were indicated. Casting was carried out in the Foundry Laboratory of the Faculty of Mechanical Engineering and Naval Architecture of the University of Zagreb. After cooling and solidification, the castings were examined using radiographic testing. The results of the radiographic test were compared with the simulation results. The recorded radiographs showed the occurrence of gas porosity and shrinkage porosity in all castings. The direct vertical casting method produced the best casting.

Zavarivanje trenjem je relativno nova i nedovoljno istražena tehnologija zavarivanja čija je svrha spajanje materijala unosom topline proizvedene trenjem. Konvencionalnim tehnologijama zavarivanja je unos topline ostvaren preko električnog luka pomoću kojeg se metali rastaljuju i formiraju međumolekulske veze koje nakon skrućivanja ostvaruju čvrst zavareni spoj. Takvim načinom zavarivanja je teško povezati dva različita metala odnosno metala koja imaju lošu metaluršku kompatibilnost koja ovisi o radijusu atoma, temperaturi tališta, rasporedu elektrona u vanjskoj ljusci, vrsti kristalne rešetke i sposobnosti stvaranja zajedničkih intermetalnih spojeva koji ojačavaju međusobne veze. Nadalje, unos topline kod zavarivanja električnim lukom je proporcionalan kvadratu jakosti struje koja se koristi pri zavarivanju što znači da unesena toplina može postići enormne vrijednosti. Prekomjeran unos topline dovodi do prekomjerno povećanih temperatura koje olakšavaju ostvarivanje nepoželjnih pojava korozije i vodikove krhkosti. Prilikom zavarivanja trenjem, kinetička energija međusobnog gibanja dijelova prelazi u toplinsku energiju i na taj način je unos topline manji. U procesu zavarivanja trenjem metali ne prelaze u tekuće agregacijsko stanje, već postižu viskozno-plastično stanje u kojem pri povišenoj temperaturi i pod utjecajem tlaka zadržavaju trajnu plastičnu deformaciju i ostvaruju trajnu vezu. Ovim postupkom moguće je zavarivati gotovo sve vrste čelika, titanove legure, magnezij, aluminij i bakar. Glavni nedostatak postupka jest što iziskuje visoka početna ulaganja i to što je uglavnom limitiran na sučeljene i kutne spojeve. U ovom diplomskom radu, navesti će se postupci zavarivanja trenjem i s njima povezani parametri te specificirati kako oni utječu na svojstva zavara. U radu će također biti navedene kombinacije materijala koje je moguće zavarivati trenjem te će se prikazati pregled industrijskih proizvoda kod kojih se koristi zavarivanje trenjem za njihovu izradu. Nadalje, utvrditi će se granični tlak sabijanja za izradu uzoraka promjera 14 mm te će se proučiti kako promjena tlaka sabijanja utječe na Al-Cu spojeve. Izrađeni uzorci će biti analizirani pomoću vlačnog testa i preko svjetlosnog mikroskopa pod uvećanjem od 200 puta. U konačnici će se prikazati rezultati ispitivanja iz kojih će biti izvučeni odgovarajući zaključci. Friction welding is relatively new and insufficiently researched welding technology whose purpose is bonding of metals enabled through heat input created through friction. Heat input of conventional welding technologies is accomplished by electric arc which melts metals that create intermolecular bonds in liquid state. Thus, after solidification is completed, firm welded connection is formed. With arc welding it is hard to bond two different metals that have unfortunate metallurgical compatibility which depends on radii of atoms, layout of outer-shell electrons, crystal lattice, melting temperature and the ability to form intermetallic compunds that strengthen the bond between metals. Furthermore, heat input in arc welding processes is proportional with rate of charges in electric current used for welding squared, which means that excessive heat can be achieved. Overwhelming amount of heat leads to increased temperatures that in turn increase the chances of corrosion and hydrogen induced cracks occurrence. With friction welding, kinetic energy of mutual motion of parts is converted into heat. That way heat input is much lower. In friction welding process, metals do not reach liquid state, but achieve permanent bond through highly viscous-plastic state in which they permanently deform through conditions of increased temperatures and pressures. With this process it is possible to weld almost all types of steel, titanium alloys, magnesium, aluminium and copper. Main drawback of this process is that it requires high starting investment and its usage is mostly limited to angular and butt joints. In this master’s thesis, friction welding processes and their process parameters will be listed. It will also be analyzed how these process parameters affect the properties of the weld. In this thesis, combinations of materials that can be friction welded will also be adduced and industrial products that have friction welding as a part of their making will be showcased. Furthermore, marginal upsetting pressure for the making of samples with the diameter of 14 mm will be established as well as the effect that upsetting pressure has on Al-Cu welds. Samples will be analyzed by tensile test and welds will be studied under optical microscope under 200x magnification. In the end, results of the testing will be shown and appropriate conclusions will be brought.

U ovom su radu obrađeni zahtjevi norme HRN EN ISO 25239 za procjenu kvalitete spojeva načinjenih postupkom zavarivanja trenjem uz miješanje. Rad se sastoji od teorijskog i eksperimentalnog dijela. U teorijskom dijelu rada ukratko su opisani pojmovi poput povijesti, parametara, prednosti, nedostataka i primjene postupka zavarivanja trenjem uz miješanje (eng. Friction stir welding (FSW)). Opisan je princip rada te detaljno obrađena geometrija radnog alata. Također, navedena su i opisana ograničenja postupka kod zavarivanja aluminija. U eksperimentalnom dijelu ispitivan je uzorak načinjen od aluminijeve legure AlSi12 postupkom zavarivanja trenjem uz miješanje. Odrađena su ispitivanja prema zahtjevima norme HRN EN ISO 25239, kako bi se ocijenila kvaliteta zavarenog spoja. Dobiveni rezultati su analizirani te je ocijenjena primjenjivost postupka pri zavarivanju aluminijevih legura. In this paper, the requirements of the HRN EN ISO 25239 standard for assessing the quality of joints made by the friction stir welding process are discussed. The paper consists of a theoretical and an experimental part. In the theoretical part of the work, terms such as history, parameters, advantages, disadvantages and applications of friction stir welding (FSW) are briefly described. The working principle is described and the geometry of the working tool is detailed. Limitations of the aluminum welding procedure are also listed and described. At the end of the theoretical part, each norm was interpreted separately. In the experimental part, a sample made of aluminum alloy AlSi12 was tested using friction stir welding. Tests were performed according to the requirements of HRN EN ISO 25239, in order to evaluate the quality of the welded joint. The obtained results were analyzed and the applicability of the procedure for welding aluminum alloys was assessed.

Uvod: Rentgenska svetloba je elektromagnetno valovanje z visoko frekvenco in majhno valovno dolžino. Snop rentgenskih fotonov, ki izhaja iz rentgenske cevi ima širok energijski spekter. Ko sevanje prehaja skozi objekt, se večina fotonov z nizko energijo absorbira v prvih nekaj centimetrih tkiva, le tisti z visoko energijo lahko prehajajo skozi objekt in dosežejo slikovni sprejemnik. Pri preiskavi se izvaja kompromis med najmanjšo dozo, ki jo radiološki inženirji omogočijo za nastanek radiograma in optimalno kakovostjo le tega – ALARA princip. Namen: Namen diplomske naloge je ugotoviti kakšen vpliv ima dodatna filtracija ter pospeševalna napetost na dozo, ki jo prejme pacient pri slikanju medenice. Metode dela: Prvi del diplomske naloge obsega predvsem pregled literature. V nadaljevanju pa sledi eksperimentalna metoda. Preverila sva kakšen je vpliv dodatne filtracije in pospeševalne napetosti na dozo pacienta pri slikanju medenice v AP projekciji. Najprej sva izvedla slikanje z lastno filtracijo, nato pa sva postopoma dodajala dodatne filtre iz aluminija in bakra. Merili smo DAP, razdaljo med goriščem in objektom. Izračunali smo efektivno dozo in dozo na določene organe, s programom PCXMC 2.0. Rezultati: Rezultati so pokazali, da se DAP povečuje s povečevanjem anodne napetosti. To lahko pojasnimo s tem, da se ob večanju anodne napetosti povečuje povprečna energija rentgenskih fotonov. Produkt toka in časa se povečuje pri povečevanju debeline dodatnih filtrov Al in Cu. Pri uporabi debelejših filtrov se DAP zniža. Dokazala sva tudi, da se efektivna doza ob povečanju debeline dodatnih filtrov ne zmanjšuje. Zanimalo naju je tudi, če se ob nižanju DAP-a niža tudi doza na organe. Iz podatkov meritev, je mogoče zaključiti, da se ob večanju debeline filtrov DAP zmanjša, doza na organe pa se poveča. Razprava in zaključek: Ugotovila sva, da je v praksi smiselno uporabljati dodatno filtracijo takrat, ko uporabljamo filtracijo 0,3 mm bakra, saj z njo znižamo dozo na večino organov. Naloga radiološkega inženirja je, da skrbi za čim nižjo dozo in ob optimalni kvaliteti rentgenograma. Introduction: X-rays are electromagnetic waves of high frequency and short wavelength. The beam of X-ray photons coming out of the X-ray tube has a broad energy spectrum - polychromatic radiation. When the radiation passes through an object, most of the low-energy photons are absorbed in the first few centimetres of tissue, leaving only the high-energy photons to pass through the object and reach the imaging receiver. The examination involves a trade-off between the minimum dose that radiological engineers can deliver to produce a radiograph and the optimum quality of the radiograph - the ALARA principle. Purpose: The purpose of this thesis is to determine the effect of additional filtration and accelerating voltage on the dose received by the patient during pelvic imaging. Methods. We have investigated the effect of additional filtration and accelerating voltage on the patient dose when imaging the pelvis in AP projection. First, we performed the imaging with self-filtration, and then we gradually added additional filters made of aluminium and copper. We measured the DAP, the object focal distance, from which we then calculated the VKD. We also calculated the effective dose and the dose to specific organs, using the PCXMC 2.0 software. This programme uses Monte Carlo simulation. The method is based on the calculation of photon transport, which depends on stochastic mathematical simulations of the interactions between photons and matter. Results. This can be related to the fact that the average energy of the X-ray photons increases with increasing anodic voltage. Also, the mAs increases with increasing thickness of the additional Al and Cu filters. We have also shown that the effective dose does not decrease with increasing thickness of the additional filters. We were interested to see if, as DAP decreases, the dose to the organs also decreases. From the measurement data obtained, it can be said that as the thickness of the filters increases, the DAP decreases, but the dose to the organs increases. The final finding was that when using larger filter thicknesses, the DAP decreases. Discussion and conclusion: We concluded that in practice it makes sense to use additional filtration as it reduces the dose to the patient. It is the task of the radiological engineer to keep the dose as low as possible and to optimise the quality of the radiograph.

U ovom radu opisana su opća svojstva aluminija i njegovih legura te značajan utjecaj na mehanička, fizikalna i kemijska svojstva metalnih materijala, točnije aluminija. Jedan od važnijih utjecaja nakon plastične deformacije odnosi se na promjene postojanosti metalnih materijala. Aluminij u odnosu na druge metale ima puno prednosti poput male mase, velike otpornosti na koroziju, mogućnosti recikliranja, jednostavnost obrade, itd. Poseban naglasak je stavljen na pozitivan, ali i negativan utjecaj plastične deformacije na korozijsku postojanost, koja naravno ovisi o načinu i temperaturi procesa te o vrsti materijala, odnosno njegovoj čvrstoći. Niska čvrstoća aluminija poboljšava se legiranjem. Plastična deformacija definirana je kao kretanje dislokacija kroz kristalnu rešetku materijala koja nastaje zbog naprezanja. Povećanjem stupanja deformacije, veća je i gustoća dislokacija u strukturi materijala. Veća je tvrdoća, ali je manja otpornost na koroziju. Povećanjem debljine površinskoga oksidnog sloja elektrokemijskim putem (eloksiranjem), povećava se otpornost aluminija prema koroziji. Tanak sloj koji nastaje, oksidni sloj, je porozan, može se obojiti i prevući organskim bojama. Boja trajno ostaje u oksidnome sloju jer se pore se zatvaraju na povišenoj temperaturi. Na korozijsku postojanost aluminijskih legura utječe u stupanj deformacije materijala. Ovaj utjecaj veći je kod nekih legura sa magnezijem (serija 5000) i silicijem (serija 6000) te se postižu bolja mehanička svojstva u slučaju toplog plastičnog oblikovanja. Primjena aluminijskih legura ograničena je pri povišenim temperaturama zbog niske temperature tališta aluminija (660 °C). Uporaba njihovih legura dozvoljena je do temperature od 150 °C do najviše 200 °C. This paper describes the general properties of aluminum and its alloys, significant influence on the mechanical, physical and chemical properties of metal materials, specifically aluminum. One of the morst important influences after plastic deformation refers to changes in the durability of metallic materials. Compared to other metals, aluminum has many advantages, such as low weight, high resistance to corrosion, recyclability, ease of processing, etc. Special emphasis is placed on the positive and negative impact of plastic deformation on corrosion resistance, which of course, depends on the method and temperature process and on the type of material, i.e. its strength. The low strength of aluminum is improved by alloying. Plastic deformation is defined as the movement of dislocations through the crystal lattice of the material that occurs due to strain. By increasing the rate of deformation, the density of dislocations in the material structure also increases. It has higher solidity, but lower resistance to corrosion. Aluminum's resistance to corrosion increases by increasing the thickness of the surface oxide layer by electrochemical means (anodization). The resulting thin layer, the oxide layer, is porous and can be painted and coated with organic dyes. The color remains permanently in the oxide layer because the pores close at elevated temperatures. The corrosion resistance of aluminum alloys is affected by the degree of deformation of the material. This influence is greater in some alloys with magnesium (series 5000) and silicon (series 6000), and better mechanical properties are achieved in the case of hot plastic forming. The use of aluminum alloys is limited at elevated temperatures due to the low melting point of aluminum (660 °C). Their use is permitted up to a temperature of 150 °C to a maximum of 200 °C

U 21. stoljeću za pakiranje pića i hrane, ambalaža mora biti ekološki prihvatljiva jer je cilj postići kružno gospodarstvo da bi se moglo pozitivno utjecati na prirodne resurse, utjecati na okoliš, ekonomiju i druga bitne elemente. Metalna ambalaža koja je proizvedena prema zakonskim propisima jedna je od ambalaže koja je ekološki prihvatljiva, kao takva svoju primjenu pronašla je u industriji za pakiranje prehrambenih proizvoda te pića. Kružno gospodarstvo nalaže ponovnu upotrebu materijala, što se u slučaju metalne ambalaže postiže procesom recikliranja. Osim što se štedi na resursima, štedi se i velika količina energije. Da bi se metalna ambalaža reciklirala potrebno ju je razvrstati/odvojiti nakon upotrebe, a zatim reciklirati da bi se ponovno primijenila kao sekundarna sirovina. Pojavom metalne ambalaže mijenja se i industrija pakiranja hrane, uz brojne napretke metal kao materijal za ambalažu je imao mnogo ključnih trenutaka u svojoj povijesti da bi postao komercijalni materijal za pakiranje hrane i pića. Najčešći materijal današnjice je ambalaža izrađena od aluminija ili čelika zbog svojih dobrih svojstva. Osim dobrih svojstva za ambalažu, metal se lako odvaja od ostalog otpada zbog magnetskih svojstva. Recikliranje je prikazano kroz postupak koji zadovoljava i ekološke i ekonomske zahtjeve koji su danas postavljeni vrlo visoko da bi se sačuvali resursi i priroda za buduće generacije. Nedostatak postrojenja za recikliranje samo je jedan od problema koji se javlja u Hrvatskoj. Istraživanje kroz percepciju stanovništva dolazi se do nekoliko bitnih zaključaka o važnosti recikliranja metalne ambalaže. Samim radom želi se prikazati značaj prikupljanja, razvrstavanja i recikliranja metalne ambalaže u suvremenom društvu.

Bijeli lim i aluminij su metalni materijali koji se upotrebljavaju za izradu ambalaže i pakiranje namirnica. Bijeli lim je kombinacija čeličnog lima i kositra, dok se aluminijska ambalaža proizvodi od vrlo čistog aluminija. Zbog brojnih dobrih osobina limenke od bijelog lima i aluminija koriste se za pakiranje različitih vrsta namirnica. Cilj ovog rada je definirati i objasniti bijeli lim i aluminij, njihove pozitivne i negativne osobine, dvodijelne i trodijelne limenke te dati primjere namirnica koje se pakiraju u ovu ambalažu. Tin plate and aluminum are metal materials that are used to make packaging for food. Tin plate is a combination of steel sheet and tin, while aluminum packaging is made of very pure aluminum. Due to their many good features, tin cans and aluminum cans are used for the packaging of different types of food. The goal of this paper is to define and explain tin plate and aluminum, their positive and negative characteristics, two-part and three-part cans, and to give examples of foods that are packed in these materials.

Za izboljšanje gospodarnosti toplega iztiskanja Al profilov je za inženirjev v praksi podaljšanje življenjske dobe orodij pomembna naloga saj ima orodje pomembno postavko pri ceni iztiskanega profila. Nastanek razpok, obraba, krušenje nitridnih plasti, plastična deformacija, lomi, itd., so najpogostejši vzroki za odpoved orodij, ki ne zagotavljajo več doseganje zahtev kupca glede kvalitete iztiskanih profilov. Katera od poškodb bo odločilno vplivala na življenjsko dobo orodja je odvisno od konstrukcije orodja, kvalitete materiala orodnega jekla, obremenitev in tehnoloških deformacijskih parametrov, izbranih parametrov nitriranja (nitridiranje), vzdrževanja, itd., i.e. gre za kompleksen problem. Izboljšanje obrabne obstojnosti drsnih površin je pomembno za podaljšanje življenjske dobe orodji pri čemer se večinoma uporablja postopek plinskega nitriranja. Ta postopek v času služenja orodja lahko tudi večkrat ponovimo. Na izbranih orodjih za toplo iztiskanje Al je bila opravljena analiza vzrokov za nastalo poškodbo ter rekonstrukcija njihovega razvoja ter tako tudi predlagane izboljšave za podaljšanje življenjskih dob analiziranih orodij. Prekomerno izločanje nitridov na kristalne meje je posledica nepravilnih parametrov nitriranja, to so čas, temperatura in potencial nitriranja. To vodi do pokanja nitridov in s tem njihovega hitrejšega adhezijskega odnašanja delov zrn z površine. Na drsnih površinah matric in trnov prevladujejo različni kontaktni pritiski, kar vodi do lokalnega povečanja obrabe na področjih maksimalnih kontaktnih pritiskov. Proces obrabe se nadaljuje z tvorbo majhnih brazd med adhezijsko odnešenimi plastmi s površine ter njihovim podaljševanjem v smeri drsenja materiala, ter tudi lateralnim širjenjem brazd oz. tvorbe žleba v lateralni smeri. Ob lateralnem dotiku dveh vzporednih brazd v smeri drsenja materiala se nam začne tvoriti žleb tudi v lateralni smeri, ki z nadalnjim razvojem obrabe vodi do tvorbe daljšega žleba po obodu drsne površine. Extending the die service time is for engineers in practice an important task for improvement the economy of hot extrusion of Al profiles since the dies have an important proportion in the price of the extruded profile. The formation of cracks, wear, crushing of nitride layers, plastic deformation, fractures, etc., are the most common causes of failure of dies, i.e. the time when used dies can not ensure the customer's requirements regarding the quality of extruded profiles, i.e. dimension tolerances, surface finish and mechanical properties. Which of the damages will be decisive at service time of dies depends on the construction of the dies (Al flow), the quality of die steels, loads and technological deformation parameters, selected parameters of nitriding, maintenance, etc., i.e. it is a complex problem. Improving the wear resistance of the sliding surfaces is important for extending the die service time whereas gas nitriding process is mostly used for improving of wear resistance of bearing surface. The process of nitriding can be repeated several times during the service lime of dies. An analysis of the causes leading to damages and a reconstruction of their development on selected dies for hot extrusion of Al were performed as well as improvements for extension of service time of the analysed dies are given. Excessive occurrence of nitrides on grain boundaries is the result of improper nitriding parameters, i.e. time, temperature and nitriding potential. This leads to the cracking of nitrides on grain boundaries and thus to accelerated adhesive removal of small parts from die bearing surface. Different contact pressures prevail around the perimeter of the bearing surface of dies and mandrels higher contact pressures leads to increase of wear, i.e. increased density of adhesive removed parts (craters) from bearing surface. The wear progress continues with the formation of small furrows between the adhesively removed craters from the surface and their lengthening in the direction of aluminium sliding, as well as the lateral expansion of the furrows or formation of the groove in the lateral direction. Upon lateral contact of two parallel furrows in the direction of sliding of the material, a groove begins to form in the lateral direction as well, which with further development of wear leads to the formation of a longer groove around the perimeter of the bearing surface.

Aluminij je jedan od najzastupljenijih metala u polju strojarstva koji osim niske gustoće i visoke korozijske postojanosti ima značajna svojstva električne i toplinske vodljivosti. Problem sirovog aluminija leži u vidu niskih vrijednosti čvrstoće i tvrdoće, mehaničkih svojstava koje su presudne prilikom izrada konstrukcijskih i strojnih dijelova. Kombinacijom legiranja te različitim parametrima toplinske obrade moguće je povećati otpornost i deformabilnost aluminija. U radu su opisana svojstva aluminij i aluminijevih legura, s posebnim naglaskom na toplinsko obradive legure, te pregled postupaka ispitivanja mehaničkih svojstava. U eksperimentalnom dijelu provedena je analiza uzoraka aluminijeve legure u polaznom stanju, te nakon dvije kombinacije toplinske obrade gdje su praćene promjene mehaničkih svojstava i mikrostrukture. Komentirani su rezultati te su doneseni određeni zaključci. Aluminum is one of the most common metals in the field of mechanical engineering, which, in addition to its low density and high corrosion resistance, has significant properties of electrical and thermal conductivity. The problem of raw aluminum lies in its low values of strength and hardness, mechanical properties that are crucial when making structural and machine parts. By combining alloying and different heat treatment parameters, it is possible to increase the resistance and deformability of aluminum. The paper describes the properties of aluminum and aluminum alloys, with a special emphasis on heat-treatable alloys, and an overview of the mechanical properties testing procedures. In the experimental part, an analysis of the aluminum alloy samples was carried out in the initial state, and after two combinations of heat treatment, where changes in mechanical properties and microstructure were monitored. The results were analyzed and certain conclusions were made.

As the microelectronic industry develops, components that can perform several different tasks receive increasingly more attention, resulting in multifunctional materials being highly sought after. ▫$Al_2O_3$▫ is widely present in electronic applications as a protective coating or as an electrical and thermal insulator due to its mechanical and thermal stabilities and chemical inertness. ▫$Al_2O_3$▫ is also an important dielectric material, with high resistivity and stable permittivity over a wide range of temperatures and electric fields, but its modest permittivity necessitates large effective areas or extremely thin layers when a large capacitance is desired. Composites consisting of discrete conducting phases within an insulating matrix can produce large capacitance via Maxwell–Wagner polarization. In this work, ▫$Al_2O_3$▫/Al composite thick films with different volume ratios of Al were prepared using the aerosol deposition method. A relative dielectric permittivity (εr′) of 800 at 1 MHz was achieved at 27 vol% of Al, a sixty-sevenfold enhancement compared to ▫$Al_2O_3$▫. On the other hand, dielectric losses, tan(δ), at 1 MHz increased from 0.01 for ▫$Al_2O_3$▫ up to 0.58 for the composite with 27 vol% of Al. A finite-element model of the composites was implemented, supporting the nonlinear electrical behavior of the composites as function of vol% of Al. Our results show novel possibilities for the applications of ▫$Al_2O_3$▫-based materials in the microelectronic industry, especially for temperature-sensitive applications, for which the integration strengths of aerosol deposition are valuable.

V tem delu je predstavljena primerjava hladilno-mazalnega učinka, pri obdelavi čistega aluminija na frezalnem stroju med klasičnim HMT (emulzijo) in kriogenim kapljevitim CO2 mešanim z razpršenim oljem (MQL). Primerjava je prikazana s pomočjo odrezovalnih sil med obdelavo, izmerjeno hrapavostjo površin in obrabo orodja. Raziskali in primerjali smo tudi vplive HMT pri različnih obdelovalnih hitrostih ter pokazala, da lahko s pomočjo kriogene obdelave desežemo višje odrezovalne histrosti z manjšo obrabo orodja. This work focuses on a comparison of the cooling and lubricating effect in the machining of pure aluminum on a milling machine between conventional CLF (emulsion) and cryogenic liquid CO2 mixed with dispersed oil (MQL). The comparison is shown with measured cutting forces during machining, measured surface roughness and tool wear. We also investigated and compared the effects of CLF, at different machining speeds and discovered, that with the help of cryogenic machining we can achive higher cutting speeds and feeds with smaller tool wear.

S povečevanjem uporabe polimernih kompozitov v letalski industriji se je povečalo tudi zanimanje za hibridne lepljene spoje, kjer se s pomočjo epoksidnih lepil spajajo kompoziti in aluminij. Spoji so lahko dodatno varovani, kar je bilo v tej raziskavi izvedeno z uporabo različnih kompozitnih sornikov. Prednost hibridnih spojev je predvsem v lahki in kompaktni konstrukciji, sloj lepila pa služi tudi kot izolator med različnima materialoma in preprečuje pojav galvanske korozije. V nalogi je bila ugotovljena višja trdnost adhezijskega spoja brez varovanja od spoja z varovanjem s sornikom, razlog za to je v zmanjšani površini lepljenja in nesočasnem prenosu sile adhezijskega in oblikovnega spoja. Višjo trdnost smo dosegali pri spojih varovanih s sornikom iz ogljikovih vlaken, saj ima manjši modul elastičnosti kot aramid, kjer je posledično prišlo do zamika prenosa sile. Laminati, izdelani z vakuumsko infuzijo, so po trdnosti primerljivi s spoji z industrijskim lepilom. Na prelomnih površinah je bila ugotovljena delaminacija plasti ogljikovih vlaken v epoksidni matrici in variiranje debeline sloja lepila, industrijsko lepilo je zdržalo vse predpisane obremenitve. With increased use of polymer composites in the aerospace industry, there has also been increased interest in development of hybrid adhesive joints, such as composites and aluminum, bonded with epoxy adhesives. Joints can be additionally protected against detachment, in this study we used different composite bolts. The main advantage of such joints is in lightweight construction, a layer of adhesive also serves as an insulation between different materials, which prevents galvanic corrosion. In this paper we prove better strength of adhesive joints without pin that secures joints from breaking, the main reason for that is in reduced gluing surface and uneven transmission of force. Higher value of strength was obtained from joints with carbon fiber pin, because of its lower elastic module, than the aramid fiber pin, where there was a delayed transmission of force. Laminates that were made with vacuum infusion, are from the mechanical point of view comparable with glued joints. On the breaking surfaces we noticed mostly delamination of carbon fibers and uneven thickness of glue, the industrial glue withstood all the specified loads.

Lithium additions to Al offer the promise of substantially reducing the weight of alloys, since each 1 wt. % Li added to Al reduces density by 3 % and increases elastic modulus. In the present work, the effect of 1.46 wt. % Li addition to AlSi7Mg (containing 7.05 wt. % Si and 0.35 wt. % Mg) was studied. The alloy showed reduced density and higher hardness after natural ageing. Experimental work showed that micro-structural and mechanical properties changed with Li addition. It was observed that 0.80 wt. % Li addition resulted in formation of new phase AlLiSi which has a great effect to increase hardness of AlSi7Mg. According to Scanning Electron Microscope (SEM) and X-ray diffraction analysis it was confirmed that the addition of Li causes formation of different phases which are: α-Al, β-Si and AlLiSi.

Ovaj rad opisuje lijevanje poklopca filtera od aluminijeve legure AlSi12 u jednokratni pješčani kalup. U radu su opisane aluminijeve legure, procesi obrade taljevine te njihovo skrućivanje. Opisan je i način konstrukcije uljevnih sustava i uloga numeričkih simulacija u ljevačkoj industriji. Eksperimentalni dio orijentiran je na razradu povoljnog uljevnog sustava s različitim veličinama i položajima pojila. Pomoću programa ProCAST izrađena je numerička simulacija svih predloženih inačica uljevnog sustava kako bi se odabrala najbolja. Također je prikazan proces kalupljenja i lijevanja odljevka sličnih karakteristika. This thesis describes casting of AlSi12 aluminium alloy filter cap using sand mould. Aluminium alloys were described, as well as melt treatment and its solidification. Gating system construction and numerical simulations importance are also in focus of the thesis. Experimental part develops gating system with different feeder sizes and positions. Using ProCAST software, numerical simulation of all suggested gating systems versions was created to choose the best. Also shown is moulding process and casting of a part with similar characteristics.

U ovom radu obrađen je postupak AC MIG i njegove prednosti u odnosu na konvencionalni MIG. Detaljno je objašnjena problematika izmjenične struje, njene prednosti i upotreba u MIG/MAG zavarivanju. Prikazan je i utjecaj polariteta struje na MIG postupak. Objašnjen je utjecaj balansa i frekvencije izmjenične struje na geometriju zavara. Također su objašnjeni problemi kod zavarivanja aluminija te koje je sve probleme moguće riješiti postupkom AC MIG u zavarivanju aluminija tanjih debljina. U eksperimentalnom dijelu rada provedeno je automatizirano AC i DC impulsno MIG navarivanje 6 uzoraka aluminijske legure 5083. Nakon navarivanja provedena je analiza deformacija u ovisnosti o vrsti struje i značajkama izmjenične struje tj. frekvencije i balansa polariteta. Izrađeni su makroizbrusci na kojima je ispitivana ovisnost geometrije zavara o značajkama izmjenične struje. Na temelju rezultata provedena je analiza te je pokazana ovisnost geometrije i deformacija zavara o značajkama izmjenične struje, te je uspoređen AC i DC MIG postupak te je pokazano da AC daje bolje rezultate, bolju kontrolu procesa i manje deformacije kod zavarivanja aluminija. The subject of this paper is the AC MIG process and its advantages over conventional MIG. The problem of alternating current, its advantages and use in MIG/MAG welding are explained in detail. The influence of current polarity on the MIG procedure is also presented. It also explains the influence of balance and frequency of alternating current on weld geometry. Problems in aluminium welding are also described and what problems can AC MIG solve in welding thinner aluminium. In the experimental part of the work, automated AC and DC pulse MIG welding of 6 samples of aluminum alloy 5083 was performed. After welding, deformation analysis was carried out to determine the dependence of deformations on current type and characteristics of alternating current, EN ratio and frequency. Macrographs were made to determine the dependence of the weld geometry on the characteristics of alternating current. Based on the results, the analysis was performed and the dependence of the geometry and deformation of welds on the characteristics of alternating current was shown, and the AC and DC MIG procedure were compared and it was shown that AC gives better results, better process control and less deformation in aluminium welding.

This current research focuses on optimizing the welding process parameters and penetration of 5052 alloys using a TIG welding process based on the Taguchi methods. Process parameters such as current, voltage, and speed with three different levels were taken to form the L27 orthogonal array using the design of experiments. Analysis of variance, signal-to-noise ratio analysis, and regression analysis were performed. The regression analysis indicated that the developed model has greater adequacy in predicting the reinforcement form factor (RFF), penetration shape factor (PSF) and hardness of the weld specimens. In addition, the optimized parametric condition for the welded specimen was found to be current, voltage, and speed of 140 A, 18 V, and 300 mm/min, respectively.

U ovom radu proučene su metode ispitivanja nemagnetskih metalnih materijala metodom vrtložnih struja. Dan je pregled radova na temu induktivnih senzorskih sustava te je projektiran i izveden induktivni senzorski sustav za ispitivanje aluminijskih šipki. Sustav se sastoji od odašiljačke zavojnice, prijemnih zavojnica u diferencijalnom ili apsolutnom spoju, sklopovlja za prilagodbu i analognu obradu signala, digitalnu akviziciju te digitalnu obradu signala u razvojnom okruženju Matlab na osobnom računalu. Ispitano je nekoliko različitih konfiguracija senzora u frekvencijskom rasponu od 20 do 500 Hz. Kao najosjetljivija konfiguracija se pokazao diferencijalni spoj zavojnica postavljenih okomito na os ispitivane šipke. Prilikom usporedbe transimpedancije izmjerenih za punu šipku i šipku s umetkom, postotna promjena modula transimpedancije je iznosila 8,42%, a promjena faze 7,13°. In this thesis eddy current testing methods for non-magnetic metals were studied. An overview of literature on induction sensors was given and a prototype of the induction sensor for aluminium rods testing was designed. The sensor consists of a transmitter coil, differential or absolute receiver coils, analog signal processing circuitry, digital acquisition and digital signal processing in Matlab on a personal computer. Several sensor configurations in the frequency range of 20 to 500 Hz were tested. Differential coils perpendicular to the axis of the examined rod proved to be the most sensitive configuration. When comparing the transimpedances measured for the solid rod and the rod with the insert, percentage change in transimpedance amplitude was 8.42% and change in phase 7,13°.

U sklopu ovog rada ispitivano je elektrokemijsko ponašanje aluminija u otopinama limunske i perklorne kiseline pri različitim pH vrijednostima, bez i s dodatkom natrijevog poli(stirensulfonata). Cilj istraživanja je određivanje utjecaja prisutnosti natrijevog poli(stiren-sulfonata) u otopinama, na kinetičke korozijske parametre. Za određivanje kinetičkih korozijskih parametara korišena je metoda potenciodinamičke polarizacije. Za karakterizaciju površine aluminija prije elektrokemijskih mjerenja korištena je metoda mikroskopije atomskih sila. Određen je utjecaj pH vrijednosti otopina na kinetičke korozijske parametre. S obzirom na utjecaj pasivnih oksidnih filmova na koroziju aluminija ispitan je utjecaj prisutnosti polielektrolita na pasivaciju aluminija i potencijalno inhibitorsko djelovanje polielektrolita. Dokazano je da prisutnost natrijevog poli(stiren-sulfonata) utječe na kinetičke korozijske parametre. U otopinama s limunskom kiselinom prisutnost polielektrolita ima sinergijski efekt, pojačava koroziju aluminija te djeluje na stabilnost oksidnog filma na površini metala. U otopinama s perklornom kiselinom vidljiv je inhibicijski utjecaj, ali i adsorpcija polielektrolita na površinu aluminija što utječe na stabilnost oksidnog filma. In this thesis, electrochemical behaviour of aluminum in citric and perchloric acid solutions, at different pH values, with or without added sodium poly(styren sulfonate) was studied. The goal of the research was determining the impact of presence of sodium poly(styren sulfonate) in solutions on kinetic corrosion parameters. The potentiodynamic polarization method was used for that purpose. The atomic force microscopy was used to characterize the aluminum surface before electrochemical measurements. The influence of solution pH on kinetic corrosion parameters was determined. Considering the influence of passive oxide films on the corrosion of aluminum, the influence of the presence of polyelectrolytes on the passivation of aluminum and the potential inhibitory effect of polyelectrolytes was investigated. The presence of sodium poly(styrene sulfonate) has been shown to affect kinetic corrosion parameters. In solutions with citric acid, the presence of polyelectrolytes has a synergistic effect, enhances the corrosion of aluminum and affects the stability of the oxide film. In solutions with perchloric acid, the inhibitory effect is visible, but also the adsorption of polyelectrolytes on the aluminum surface, which affects the stability of the oxide film.

This study enhances the strength of the Al6061 alloy by adding Ti in the form of a rod using a thermomechanical process, which would be useful in making structures for aerospace and structural members. Two different properties of the material are joined together to form a new bimetallic material. Softer Al-6061 is used as a sleeve, and grade-II Ti is used as a core. They were prepared with a co-extrusion process at a temperature of 400 °C with different ratios of 2:1 and 2:0.5. The prepared substrates are analysed for characterization, hardness, tensile strength, and corrosion. The development of the diffusion layer is observed at the boundary of the Al-Ti material, and the bonding is improved. Compared to an aluminium alloy and a 2:1 bimetal composite, the co-extruded Al-Ti with a ratio of 2:0.5 bimetal composite ratio shows a better microstructure, mechanical, and tribological properties. It is concluded that the co-extrusion of Ti and Al is an efficient way to devise new composites with mechanical properties of 14% and 19%, respectively.

V zaključni nalogi je predstavljena raziskava in analiza izdelave hladilnih reber iz aluminija s preoblikovalnim postopkom istosmernega iztiskavanja, ki bi lahko služila za hlajenje LED žarometov. Predstavili smo potek analiziranja vplivov tehnoloških parametrov in oblik po načrtu Taguchijeve ortogonalne matrike, eksperimente pa izpeljali s pomočjo simulacij, ki smo jih izvajali s programsko opremo QForm. Glede na najbolj ugodne rezultate smo postavili model, za katerega smo zasnovali in skonstruirali orodje. Za končan model orodja smo naročili material in poslali povprašanje za izdelavo lokalnim orodjarjem s ciljem realizacije izdelka. The thesis deals with the research and analysis of making aluminium cooling fins using the one direction extrusion process, the final product being utilized for cooling LED lights. The course of the analysis of impacts of technological parameters, as well as shapes, according to the Taguchi Orthogonal Matrix, has been presented. The experiments were carried out in the form of simulation, using the QForm software. According to the optimal results a model has been formed, along with the design and construction of the tools for its fabrication. Finishing the ultimate model of the tools was followed by commission of the material and inquiry among the local toolmakers in order to finalize the project.

The use of wood-based materials in building and construction is constantly increasing as environmental aspects and sustainability gain importance. For structural applications, however, there are many examples where hybrid material systems are needed to fulfil the specific mechanical requirements of the individual application. In particular, metal reinforcements are a common solution to enhance the mechanical properties of a wooden structural element. Metal-reinforced wood components further help to reduce cross-sectional sizes of load-bearing structures, improve the attachment of masonry or other materials, enhance the seismic safety and tremor dissipation capacity, as well as the durability of the structural elements in highly humid environments and under high permanent mechanical load. A critical factor to achieve these benefits, however, is the mechanical joint between the different material classes, namely the wood and metal parts. Currently, this joint is formed using epoxy or polyurethane (PU) adhesives, the former yielding highest mechanical strengths, whereas the latter presents a compromise between mechanical and economical constraints. Regarding sustainability and economic viability, the utilization of different adhesive systems would be preferable, whereas mechanical stabilities yielded for metal-wood joints do not permit for the use of other common adhesive systems in such structural applications. This study extends previous research on the use of non-thermal air plasma pretreatments for the formation of wood-metal joints. The plasma treatments of Norway spruce [Picea abies (L.) Karst.] wood and anodized (E6/EV1) aluminum AlMgSi0.5 (6060) F22 were optimized, using water contact angle measurements to determine the effect and homogeneity of plasma treatments. The adhesive bond strengths of plasma-pretreated and untreated specimens were tested with commercial 2-component epoxy, PU, melamine-urea formaldehyde (MUF), polyvinyl acetate (PVAc), and construction adhesive glue systems. The influence of plasma treatments on the mechanical performance of the compounds was evaluated for one selected glue system via bending strength tests. The impact of the hybrid interface between metal and wood was isolated for the tests by using five-layer laminates from three wood lamellae enclosing two aluminum plates, thereby excluding the influence of congeneric wood-wood bonds. The effect of the plasma treatments is discussed based on the chemical and physical modifications of the substrates and the respective interaction mechanisms with the glue systems. Nasl. z nasl. zaslona. Opis vira z dne 18. 1. 2022. Objavljeno na spletu 17. 1. 2022. Št. prispevka 796474. Bibliografija: str. 9-10.

Svrha ovog diplomskog rada je usporediti i dimenzionirati elemente montažne aluminijske hale na području grada Osijeka. Tlocrtne dimenzije hale su 15x25 m, visine 8,06 m do vrha sljemena s nagibom krova od 26°. Ista hala proračunata je na dva načina. Prvi način je proračun djelovanja HRN EN 1991 (trajne aluminijske konstrukcije), a drugi je proračun prema normi HRN EN 13782 (privremene konstrukcije – šatori). Obje konstrukcije su dimenzionirane prema HRN EN 1999. Za stupove i grede, u oba proračuna, korišteni su aluminijski profili s utorima za lakše montiranje PVC pokrova hale, a za podrožnice su korišteni šuplji pravokutni presjeci. Postavljanjem vertikalnih i horizontalnih spregova osigurana je prostorna stabilnost hale. Spregovi su kružnog poprečnog presjeka. Veći momenti savijanja na mjestima spajanja elemenata riješeni su izvedbom čeličnog umetka kvalitete čelika S235. Statička analiza i proračun su provedeni u programskom paketu Autodesk Robot Structural Analysis 2022., The purpose of this thesis is to compare and design the elements of a prefabricated aluminium hall around the city of Osijek. The ground plan dimensions of the hall are 15x25 m, the height is 8.06 m to the top of the ridge with a roof slope of 26°. The same hall is calculated in two ways. The first method is the calculation of loads according to HRN EN 1991 (permanent aluminium structures), and the second is the calculation according to the HRN EN 13782 standard (temporary structures - tents). Both constructions are designed according to HRN EN 1999. Aluminium profiles with slots for easier mounting of the hall's PVC cover were used for the columns and beams, and hollow rectangular sections were used for the beams. By installing vertical and horizontal joints, the spatial stability of the hall is ensured. The couplings have a circular cross-section. Larger bending moments at the points of connection of elements are solved by the execution of a steel insert of S235 quality. The static analysis and calculation were performed in the Autodesk Robot Structural Analysis 2022 software package.

U ovome radu razmatrala se prehrambena ambalaža mliječnih proizvoda. Mliječni proizvodi su specifičan prehrambeni proizvod koji prilikom pakiranja u ambalaže mora zadovoljiti niz zakonodavnih i zdravstvenih uvjeta. U Republici Hrvatskoj takvi proizvodi pakirani su uglavnom u ambalažu od polipropilena ili polistirena sa aluminijskom folijom. Maseni udio aluminija u ambalažama je znatno manji od plastike. Otprilike 93% mase ambalaže čini plastika, a 7 % aluminij. Kako bi se postigla što veća učinkovitost za daljnje recikliranje, ta dva materijala potrebno je prvo razdvojiti. Cilj ovoga rada je u što većem postotku razdvojiti aluminij od plastike, kao vrlo vrijedan materijal koji se može gotovo neograničeno reciklirati bez gubitaka kvalitete materijala. U laboratorijskim ispitivanjima ovog istraživanja korištene su tri separacijske metode: magnetska separacija sa vrtložnim strujama, elektrostatička separacija te pliva- tone separacija.

Tema ovog završnog rada je korozijska postojanost slojeva aluminijske legure dobivene postupkom aditivne proizvodnje električnim lukom i žicom (WAAM). Rad je podijeljen u dva dijela, prvi teorijski i drugi eksperimentalni. U teorijskom dijelu opisani su postupci aditivne proizvodnje, te uspoređeni međusobno. Opisane su prednosti i nedostaci postupka aditivne proizvodnje električnim lukom i žicom u odnosu na tradicionalne postupke proizvodnje. Navedeni su i opisani najčešći oblici korozije koji se pojavljuju kod aluminija i njegovih legura. Nadalje, opisana je podjela aluminijskih legura prema načinu proizvodnje i objašnjeno njihovo označavanje. Navedena je podjela aluminijskih legura prema glavnom legirnom elementu, te opisan utjecaj tog legirnog elementa na mehanička svojstva i korozijsku otpornost aluminijske legure. Na kraju teorijskog dijela opisan je utjecaj postupka aditivne proizvodnje električnim lukom i žicom na korozijsku otpornost aluminijske legure serije 5XXX. U eksperimentalnom dijelu, opisana je aditivna proizvodnja uzorka (WAAM), izrada manjih uzoraka na kojima će se provesti ispitivanja, njihova naknadna obrada i priprema. Ukupno su ispitana četiri uzorka, tri odvojena strojnom obradom s uzorka proizvedenog aditivno (WAAM), i jedan uzorak od osnovnog materijala, aluminijske legure 5083. Ispitan je kemijski sastav izrađenih uzoraka, te su provedena elektrokemijska ispitivanja. Rezultati su analizirani i uspoređeni. The topic of this thesis is the corrosion resistance of aluminum alloy layers obtained by the process of wire arc additive manufacturing (WAAM). The paper is divided into two parts, the first is theoretical and the second is experimental. The theoretical part describes the processes of additive manufacturing and compares them. The advantages and disadvantages of the wire arc additive manufacturing relation to traditional manufacturing processes are described. The most common forms of corrosion that occur in aluminum and its alloys are listed and described. Furthermore, the division of aluminum alloys according to the method of manufacturing is described and their numeration is explained. The division of aluminum alloys according to their main alloying element is given, and the influence of the main alloying element on the mechanical properties and corrosion resistance of aluminum alloy is described. At the end of the theoretical part, the influence of the wire arc additive manufacturing on the corrosion resistance of aluminum alloy series 5XXX is described. In the experimental part, wire arc additive manufacturing (WAAM) of the sample, production of smaller samples on which tests will be performed, their post-processing and preparation are described. A total of four samples were tested, three separated by machining from a sample manufactured additively (WAAM), and one sample of base material, aluminum alloy 5083. The chemical composition of the samples was tested, and electrochemical tests were performed. The results were analyzed and compared.

Cilj diplomskog rada je odabir odgovarajućeg konstrukcijskog sustava, te dimenzioniranje čelične i aluminijske inačice hale. Analiza opterećenja i dimenzioniranje provedeno je u skladu s normama HRN EN 1993 i HRN EN 1999. Opterećenja uzeta u obzir, uz vlastitu težinu, su snijeg i vjetar. Analiza reznih sila na temelju unesenih kombinacija je rađena u programskom paketu Robot Structural Analysis 2019. Okvir čelične konstrukcije, stup i greda, izvedeni su s IPE 450 profilom, a podrožnica je izvedena kao toplo dogotovljeni pravokutni profil dimenzija 100/60/6 mm. Pri izradi aluminijske okvirne konstrukcije korišteni su vlastito osmišljeni profili za stup, gredu i podrožnice. Proračunom su zadovoljeni uvjeti graničnih stanja nosivosti i uporabljivosti čelične i aluminijske hale. Također, dan je i izvještaj o spojevima proračunatim pomoću Autodesk Robot Structural Analysis 2019., The aim of the thesis is to select the appropriate structural system and design the steel and aluminum version of the hall. Load analysis and dimensioning was carried out in accordance with HRN EN 1993 and HRN EN 1999. Loads considered, in addition to own weight, are snow and wind. The analysis of forces and moments, based on the entered combinations was done in the program package Robot Structural Analysis 2019. The frame of the steel structure, the column, and the beam, were made with the IPE 450 profiles, and the purlin was made as a hot-finished rectangular profile with dimensions of 100/60/6 mm. When creating the aluminum frame structure, specially designed profiles for the column, beam and purlins were used. The calculation satisfies the conditions of the ultimate limit state and serviceability limit state of the steel and aluminum hall. Also, a report on joints calculated using Autodesk Robot Structural Analysis 2019 was given.

Rad obrađuje utjecaj aluminijskih posmičnih panela na odgovor konstrukcije pri potresnom djelovanju. Do sada je razvijen popriličan broj inženjerskih rješenja u projektiranju zgrada koje pružaju nekakvu ili veću otpornost na potres, međutim napretkom tehnologije i sve rigoroznijim zahtjevima građenja dolazi do potrebe za novim, prigodnijim i/ili bolje iskorištenim materijalima. U toj problematici do izražaja dolazi aluminij kao materijal sa značajnim prednostima nad tradicionalno korištenim materijalima te posmični panel kao element koji će preuzeti na sebe opterećenje za dobrobit nosive konstrukcije te time pridonijeti ne boljem ponašanju što ujedno predstavlja i ostala inženjerska rješenja. Složeno stanje naprezanja koje se javlja u aluminijskim posmičnim panelima obuhvaćeno je numeričkim i analitičkim modelima pomoću kojih je moguće dobiti preciznije informacije o ponašanju i utjecaju ovakvih panela. Kako bi se uvidio doprinos aluminijskih posmičnih panela na odabranom okvirnom sustavu, učinjena je usporedba gdje su na istom okvirnom sustavu primijenjene tradicionalne ispune zidova te su isto tako varirana svojstva sam odabrani materijal pogodan za ovu vrstu opterećenja., This thesis deals with how the aluminium shear panel impacts the seismic response characteristics of a building during an earthquake. There are quite a number of earthquake - resistant technologies developed up until now, but as technology progresses, engineers are in need of of new solutions in terms materials or better use of their attributes. Aluminium is a material with great number of advantages when it comes to withstanding lateral forces produce by seismic waves especially when compared to other materials. It will apsorb disipated energy in order to prevent damaging impact on surrounding construction frame, which will contribute stated achiving better behaviour. The rest of engineened solutions ara stated. Because the strain state in aluminium shear panels appears to be vety complex, it has to be modeled and analyzed by numerical and analytical models and calculations ti obtain more precise information about how it behaves. To determine how valid and useful the contribution of aluminium shear panels is on a given frame structure, a comparison with the same frame structure but with traditional infill / walls was required.

Tema ovog diplomskog rada je „Analiza primjene AC MIG postupka za zavarivanje tankih limova legure AlMg3“. Rad je podijeljen u dva glavna dijela, a to su teorijski te eksperimentalni. U teorijskom dijelu prikazane su glavne karakteristike spomenutog materijala od kojih je za ovaj rad najvažnija zavarljivost. Također, opisane su glavne karakteristike MIG te AC MIG postupaka zavarivanja koji se koriste u eksperimentalnom dijelu rada. U eksperimentalnom dijelu opisano je zavarivanje sučeljenog spoja aluminijeve legure 5086 debljine 3 mm konvencionalnim DC te modificiranim AC MIG postupkom. Zavareni spojevi su ispitani, a rezultati analizirani prema normi HRN EN ISO 15614-2. Ispitivanja koja su provedena su vizualni pregled, ispitivanje penetrantima, statičko vlačno ispitivanje, ispitivanje savijanjem te analiza makrostrukture. Nakon razmatranja teorijskog i eksperimentalnog dijela rezultati su analizirani i na temelju njih donesen je zaključak. The topic of this master thesis is "Analysis of application of AC MIG process in welding of thin AlMg3 alloy sheets". The paper is divided into two parts, the first part is theoretical and the second is experimental. In the theoretical part, the main characteristics of the mentioned material are presented, of which weldability is the most important for this work. Also, the main characteristics of MIG and AC MIG welding procedures used in the experimental part of the work are described. The experimental part describes the welding of a 3 mm thick 5086 aluminium alloy butt joint by conventional DC and modified AC MIG welding processes. Welded joints were tested, and the results were analyzed according to the HRN EN ISO 15614-2 standard. Performed tests were visual inspection, penetrant testing, transverse tensile testing, transverse bending testing and macroscopic examination. After considering theoretical and experimental part, the test results were analyzed and conclusion was reached.

Continuous advancements in the electrification of the whole automotive industry rely heavily on the use of lightweight materials. Due to the overall requirements for mass reduction that such rapid development imposes, lightweight materials such as aluminum play a major role in the optimization and development of powertrain components and vehicles while at the same time ensuring the structural integrity of the system. In the introduction of this thesis a short overview of the four most common fatigue assessment methods is given which includes the description of the approaches based on nominal stress, structural hot spot stress, and effective notch stress as well as the crack propagation analysis. In the continuation of the thesis the focus will be on the fatigue assessment of weld seams joining extruded aluminum profiles with the use of modern-day fatigue assessment tools. A closer look will be given into the notch stress-based method behind FEMFAT Weld analysis tool and its benefits for the weld seam fatigue investigations. The fatigue assessment method for welded components proposed by FEMFAT Weld will be validated on an example of welded aluminum profiles from the literature before final experimental investigations begin. In the main focus of the work will be the high cycle fatigue testing of two different weld seams, I-seam butt weld and corner fillet weld, both made of extruded aluminum profiles. Along with the high cycle fatigue testing, additional microscopic measurements of the weld geometry and hardness will be performed. The results of such investigations will be used to conduct a thorough investigation of FEMFAT Weld in order to understand the notch stress methods that are being used and apply them in the desired way. The final results of fatigue assessment with the use of FEMFAT Weld analysis tool will be compared to the results from high cycle fatigue tests and certain conclusion will be drawn. In the end the work from this thesis will represent a detailed overview of FEMFAT Weld assessment tool and clear instructions on how to customize it to specific needs in respect to weld fatigue assessment. Neprestani napredak u elektrifikaciji cijele automobilske industrije uvelike se oslanja na korištenje lakih materijala. Zbog općih zahtjeva i potreba za smanjenjem mase koje nameće takav napredak, laki materijal kao što je aluminij igraju bitnu ulogu u optimizaciji i razvoju komponenti kako pogonskog sklopa tako i cijelog vozila, dok u isto vrijeme moraju osigurati strukturalni integritet cijelog sustava. U uvodu ovog diplomskog rada dan je kratak pregled četiri najčešće metode procjene zamora koji uključuje opis pristupa temeljenih na nominalnom naprezanju, strukturnom „hot spot“ naprezanju i efektivnom zareznom naprezanju, kao i opis analize propagacije pukotine. U nastavku rada fokus će biti na procjeni zamora šavnih zavara koji spajaju ekstrudirane aluminijske profile uz korištenje suvremenih alata za procjenu zamora. Detaljnije će se razmotriti metoda koja stoji iza FEMFAT Weld simulacijskog alata, a temelji se na zareznom naprezanju, kao i njene prednosti u procjeni zamora. Metoda procjene zamora za zavarene komponente koju predlaže FEMFAT Weld bit će provjerena na primjeru zavarenih aluminijskih profila preuzetom iz literature, prije samog početka eksperimentalnih ispitivanja. U glavnom fokusu rada bit će ispitivanje visokocikličkog zamora dvaju različitih šavnih zavara izrađenih od ekstrudiranih aluminijskih profila, sučeonog I-zavara i kutnog zavara. Uz visokocikličko ispitivanje zamora, izvršit će se i dodatna mikroskopska mjerenja geometrije te mjerenje tvrdoće zavara. Rezultati tih istraživanja poslužit će za provedbu temeljitog istraživanja FEMFAT Weld alata kako bi se bolje razumjele metode zareznih naprezanja koje se koriste kako bi ih se moglo primijeniti na željeni način. Konačni rezultati procjene zamora korištenjem FEMFAT Weld alata usporedit će se s rezultatima ispitivanja visokocikličkog zamora te će se izvući odgovarajući zaključci. Ovaj diplomski rad na kraju će predstavljati detaljan pregled FEMFAT Weld simulacijskog alata i jasne upute kako ga prilagoditi specifičnim potrebama u pogledu procjene zamora zavarenih spojeva.

Imajući u vidu česte primjene prostornih rešetkastih konstrukcija za natkrivanje većih prostora s većim rasponima, gdje vlastita težina predstavlja velik udio u ukupnom opterećenju, osmišljena je prostorna rešetkasta konstrukcija koja može imati namjenu autobusnog kolodvora, sajamskog prostora i slične namjene. Prvi dio rada uključuje pregled takvih konstrukcija i razloge zašto je aluminij prikladan za takvu vrstu konstrukcija. Unutar pregleda odabrana je postojeća prostorna rešetkasta čelična konstrukcija (na graničnom prijelazu Gradiška u Bosni i Hercegovini) te pribavljeno dovoljno podataka o njoj i reproduciran proračun aluminija i čelika na tom primjeru, uz danas važeće norme. Napravljena su dva modela, čelična i aluminijska inačica konstrukcije. Izvršeno je dimenzioniranje elemenata svakog od modela u programskom paketu Scia Engineer 19.1. Težilo se ujednačenom postotku iskorištenosti elemenata između modela u svrhu bolje usporedbe osnovnih troškova dvije inačice izvedbe jednake konstrukcije. Proračunati su osnovni troškovi obiju inačica izvedbe jednake konstrukcije. Razlika u ukupnoj cijeni za 9 posto (aluminijska konstrukcija je skuplja za 9 posto), a sve navedene prednosti aluminija navela je na zaključak da bi opravdano rješenje bilo konstrukciju ovakvog tipa napraviti u aluminiju. Naročito bi to bilo opravdano napraviti u kemijski agresivnim sredinama jer su manji troškovi održavanja pa bi dugoročno gledajući aluminijska varijanta bila isplativija. Nadalje je opisana izvedba te izrađena izvedbena dokumentacija za aluminijsku inačicu konstrukcije. Također, obratila se pozornost na moguću pojavu kontaktne korozije na dijelovima konstrukcije gdje dolazi do kontakta aluminija i čelika te su opisane mjere njene prevencije. Ključne riječi, Considering the frequent use of space truss structures to cover larger spaces with larger spans, where the self-weight represents a large share of the total load, a space truss structure was designed that can be used as a bus station, fair space and for similar purposes. The first part of the paper includes an overview of such structures and the reasons why aluminium is suitable for this type of structure. Within the review, the existing space truss steel structure was selected (at the border crossing Gradiška in Bosnia and Herzegovina). Thus, sufficient data was obtained for the mentioned construction and the calculation of aluminium and steel structure on that example was reproduced, according to current standards. Two models were made, steel and an aluminium version of the construction. The designing of the elements of each of the models was performed in the Scia Engineer 19.1 software package. A uniform percentage of utilization of elements between models was sought in order to better compare the basic costs of two versions of the same construction. The basic costs of both versions of the same construction have been calculated. The difference in the total price by 9 percent (aluminium construction is 9 percent more expensive), and all the above advantages of aluminium led to the conclusion that a justified solution would be to make a construction of this type in aluminium. It would be especially justified to do this in chemically aggressive environments because the maintenance costs are lower, so in the long run, the aluminium variant would be more costeffective. Furthermore, the execution of the structure is described and plans for the aluminium version of the structure prepared. Also, attention was made to the possible occurrence of contact corrosion on parts of the structure where aluminium and steel come into contact, and measures for its prevention were described.

U ovom radu istražene su emisije štetnih tvari u zrak (aeropolutanata) u pogonu plastifikacije metala (aluminija). Opisan je tehnološki proces nanošenja bojila u prahu na površinu metalnog obratka elektrostatskim postupkom, te su provjerene emisije dušikovih oksida iz ispusta peći za polimerizaciju. Također, provjereni su iznosi dimnih brojeva te emisija ugljikovog monoksida i dušikovih oksida na ispustu toplozračnog termogena peći za sušenje s tlačnim gorionikom, toplovodnog kotla s tlačnim plinskim gorionikom te na ispustu toplozračnog plinskog termogena peći za polimerizaciju. Dobivene vrijednosti su uspoređene s propisanim vrijednostima u Uredbi o graničnim vrijednostima emisija onečišćujućih tvari u zrak iz nepokretnih izvora. In this study emissions of air pollutants in metal (aluminium) plastification industry were investigated. The technological process of metal workpiece powder coating by electrostatic process was described, and the emissions of nitrogen oxides from the outlet of the polymerization furnace were checked. Also, the amounts of smoke numbers and emissions of carbon monoxide and nitrogen oxides at the outlet of the hot air thermogene drying kiln with pressure burner, hot water boiler with pressure gas burner and at the outlet of hot air gas thermogene kiln for polymerization were researched. The obtained values were compared with the prescribed values in the Regulation on limit values for emissions of pollutants into the air from stationary sources.

Tehnologija hladnega napraševanja je precej nepoznana ampak hitro razvijajoča tehnologija za nanos prevlek. Cilj naloge je združitev tehnologije hladnega napraševanja z računalniško vodenim numeričnim krmiljenjem, za namene napraševanja aluminijevega prahu na ZnO keramično površino. Tekom eksperimentalne faze je bil didaktični CNC stroj Emco concept mill 105 integriran z prenosnim hladnim napraševalnikom Dymet. Z omenjenim sistemom je bila na ZnO keramično ploščico nanešena aluminijeva prevleka. Analiza rezultatov je zajemala analizo debelin nanosa in trdnosti vezi nanosa, ta se je preverila z preskušanjem oprijema z odtrganjem filma po standardu ISO 4624. Rezultati so potrdili ustreznost tehnologije hladnega napraševanja za nanos aluminija na ZnO keramične površine. Cold spraying technology is relatively unknown but fast developing coating technology. The aim of this work is to combine cold spraying technology with computer numerical control for the purpose of spraying aluminium powder on ZnO ceramic surfaces. During the experimental phase, Emco concept mill 105 didactic CNC machine was integrated with a Dymet portable cold spray machine. With this system, aluminium coating was applied to a ZnO ceramic tile. The analysis of results consisted of coating thickness analysis and verification of coating bond strength by pull off test according to ISO 4624 standard. The results confirmed the suitability of the cold spray technology for the deposition of aluminium on ZnO ceramic surfaces.