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In this technical world, the properties and internal structure of materials renders a vital part in building up of the components for various specific purposes and improvise their efficiencies in a better way. The combination of copper with other metals is always an interesting one. In this, brass of grade BS90 is an alloy of zinc added with copper and it is lustrous in nature. The amount of zinc that is mixed with copper can be varied to develop different categories of brass with different melting temperatures that develops distinct electrical and mechanical potency. In the process of better understanding of the powder metallurgy technique and analyzing and improvising the properties of brass, this research is carried out. Primarily, this process is carried out based on the powder metallurgy technique. The prime intention of this investigation is to develop and process the specimens under predetermined conditions of powder metallurgy and then their mechanical hardness and the microstructure are to be characterized. The secondary objective is to analyze these characteristic values and compare them relatively to the specified conditions.

One of the utmost important liquid lubrication regime is mixed lubrication regime as it occurs in almost all of the industrial machines & equipments. The most of the major impairments such as wear, micro pitting etc. happen in this lubrication regime. These days, mixed lubrication regime is the least tacit and so a lot of scope for the research is available in the same. Therefore, authors have focused themselves to investigate the effect on various tribological parameters i.e., friction & wear for sliding pair of EN31 & Brass with VG-46 & VG-32 hydraulic oils in mixed lubrication regime. This tribological pair is the most important and standard pair used in various industrial applications. VG-46 & VG-32 are also the most effective lubricants used in various industrial setups. This study will be helpful for various practical applications further because of its widely industrial applicability.

L'utilisation des techniques de nettoyage des marqueteries métalliques par abrasion mécanique a pu entraîner au cours du temps la disparition d’éléments décoratifs tels que la gravure en taille douce. Dans le cadre du projet interdisciplinaire de recherche appliquée à la restauration des meubles Boulle mené avec le musée du Louvre, le C2RMF a développé de nouvelles méthodes de nettoyage par gels de solvants, non dommageables pour la surface, en quantifiant les niveaux d’élimination de l’oxydation. Used over long periods of time, cleaning techniques for metal marquetry involving mechanical abrasion have led to the loss of decorative elements such as line-engraving. As part of the interdisciplinary applied research project undertaken with the Louvre on the restoration of Boulle furniture, the C2RMF developed new methods of cleaning metals with solvent gels, which do not harm the surface but remove discoloured layers.

Refractory high entropy alloys (RHEAs) have shown great promise for a multitude of advanced engineering applications due to their high mechanical stability from cryogenic temperatures to 1600 °C. However, the low ductility they exhibit at room temperature limits their machinability when traditional machining techniques are used. Studies on the nontraditional machining of RHEAs, on the other hand, are very limited. In the present work, MoNbTaTiZr RHEAs subjected to wire electrical discharge machining (WEDM) were examined using electron microscopy, contact profilometry, and nanoindentation. Voids, microcracks, and recast material were observed on the machined surfaces. A transition from roughing to finishing decreased the amount of recast material, but the density of observable voids and microcracks on the surface increased. Optimal results were obtained by finishing, where the surface quality was improved by the removal of recast material remaining from prior passes. The brass wire electrode provided a smoother surface while the copper-core electrode provided minor heat-affected zone in the MoNbTaTiZr samples. In the roughing cuts, a 7.00% improvement in surface roughness was achieved using the copper-core electrode compared to the brass electrode. In the semi-finishing and finishing cuts, the brass wire electrode provided improvements of 13.68% and 22.68%, respectively, compared to the copper-core electrode. On the other hand, the wear of the brass electrode was as much as 20.98% higher than that of the copper-core electrode.

In this paper, potentiostatic and galvanostatic deposition (electrochemical deposition) processes have been used for the obtained of a new composite polymer: N-methylpyrrole-sodium 1-dodecanesulfonate/poly 2-methylthiophene (PNMPY-1SSD/P2MT) coatings over brass electrode for corrosion protection. The sodium 1-dodecanesulfonate as a dopant ion employed in the electropolymerization procedure can have a meaningful effect on the anti-corrosion protection of the composite polymeric film by stopping the penetration of corrosive ions. The composite coatings have been characterized by cyclic voltammetry, Fourier transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM) procedures. The anti-corrosion performance of PNMPY-1SSD/P2MT coated brass has been investigated by potentiostatic and potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) practices in 0.5 M H2SO4 medium. The corrosion assessment of PNMPY-1SSD/P2MT coated brass was noticed to be ~9 times diminished than of uncoated brass, and the efficiency of these protective coatings of this coating is above 90%. The highest effectiveness is realized by the electrochemical deposition of PNMPY-1SSD/P2MT obtained at 1.1 V and 1.4 V potential applied and at 0.5 mA/cm2 and 1 mA/cm2 current densities applied in molar ratio 5:3. The outcomes of the corrosion tests denoted that PNMPY-1SSD/P2MT coatings assure good anti-corrosion protection of brass in corrosive media.

This study outlines a novel and sustainable electrodeposition-redox replacement (EDRR) method to produce Cu/Zn alloys using a simulated hydrometallurgical Zn solution containing 200 ppm Cu, 65 g/L Zn, and 10 g/L H2SO4. The results indicate that by tailoring the EDRR parameters, like deposition time, replacement time, and agitation conditions, Cu/Zn alloys with controllable properties including chemical composition, microstructures, colorations, and crystalline phases can be readily obtained. Scanning electron microscopy (SEM) analysis shows that coherent Cu/Zn films grow from separate nanoscale particles produced during the initial EDRR cycles. Furthermore, the corrosion performance of the prepared Cu/Zn films is tunable by changing the crystalline phases through the variation of operating conditions. For example, deposits containing Zn-rich phases (CuZn5, Cu5Zn8) obtained with short redox replacement times without agitation resulted in relatively poor corrosion resistance. In contrast, Cu-rich phases (Cu0.75Zn0.25, Cu0.85Zn0.15) with enhanced corrosion performance were achieved with prolonged redox replacement times and/or the application of magnetic stirring. Unlike traditional electrodeposition, the EDRR method does not involve any complexing agents and the currently underutilized hydrometallurgical solutions were used as potential raw materials. Overall, the study suggests the EDRR method as a promising approach to achieve sustainable manufacturing of Cu/Zn alloys and an improved circular economy of metals.

A homogeneously ultrafine-grained (UFG) Cu-38 Zn alloy with an average grain size of 0.64 μm is successfully fabricated by equal channel angular processing (ECAP), which exhibits a significantly enhanced strength-ductility synergy. The strength enhancement can be attributed to grain refinement and dislocation strengthening. After annealing the ECAP processed alloy at 300 °C for 30 min, a further enhanced strength with almost unchanged ductility was achieved. This unusual annealing strengthens is associated with the solute/impurity segregation and precipitations inside the grains.

In this paper, it was used a monolithic-type structured photoreactor with a high surface area calcined brass as a substrate for TiO2-P25. The TiO2 immobilization over the monoliths was carried out by the washcoating process. The films were characterized via XRD and diffuse reflectance. The monoliths were tested at a recirculation reactor using a solar simulator as an energy source and their efficiency was evaluated at Reactive Black 5 (RB5) textile dye photodegradation. It was investigated the effect of the impregnated catalyst mass, the monolith size, the initial dye concentration and the reaction medium pH. The preliminary tests of the brass calcination temperature (500, 600, and 700 °C) showed the formation of ZnO and CuO semiconductors at the brass surface, thus suggesting that the monoliths can act as photocatalysts. Furthermore, the brass calcined at 500 °C showed the greater formation of both oxides (ZnO and CuO) and greater photocatalytic efficiency. The TiO2/brass monolith presented more than 59 % of degradation for an initial dye concentration of 12.5 mg.L−1. In regarding to stability test, the system set forth a decrease at RB5 degradation efficiency of 62 % and presented an adherence of 77.5 % after 5 cycles of monoliths reuse. Therefore, the brass monolithic systems with immobilized TiO2 showed to be a feasible alternative for textile effluent treatment.

Aluminium metal matrix composites (AMMC) have become increasingly prevalent because of their lighter mass in the aerospace and automobile businesses. Machining of such composites was challenging because of the reinforcement influence. Compared to other unconventional machining methods, AMMC machining by EDM provides better machining attributes. The workpiece's electrical conduction affects machinability via EDM. A comparative analysis on fabrication and EDM of Al6061/SiC composite using different sorts of electrodes, i.e., copper and brass was carried out during the investigation. A L27 orthogonal array was employed to generate mathematical configurations. The consequences on the material removal rate (MRR) and tool wear rate (TWR) on the individual process parameters, i.e., gap voltage (V), pulse off time (Toff), current (I) and pulse on time (Ton) have been studied. Studies indicated that brass electrode attained a relatively high material removal rate opposed to copper electrode. Although copper electrode achieved lower value than brass electrode for tool wear rate.

Brass has an interesting set of characteristics, such as good wear capabilities and high electrical and thermal conductivity. Aluminium has been utilized as reinforcement and matrix in the development of advanced composites. In the present investigation, the new unique material the brass/Al composite has been developed by liquid casting route. The effect of Al filler in varying wt.% on the mechanical properties of new brass/Al composites were investigated. The tensile strength and hardness were evaluated for produced composites. The microstructural features were observed by optical microscopy. The optical microscopy revealed the uniform distribution of Al particles in the brass matrix. The tensile strength and hardness increased by increasing the Al contents. It was interestingly observed that the addition of 4 wt% Al exhibits the uniform distribution of irregular block shape strengthening phase and has the best mechanical properties. The fine surface was obtained by addition of Al. This research work provides an advanced strategy for improving the overall characteristics of existing brass.

The effect of numerous process variables has been explored for surface roughness and material removal rate during the magnetic abrasive finishing process. A hybrid approach was used in which the Taguchi technique is used in conjunction with grey relational analysis to reach the optimum combination of input variables. The L16 orthogonal array design was used to get a different combination of parameters. It was found that spindle speed of 200 rpm, the quantity of magnetic abrasives of 5 mg, mesh number of 270, and machining time 60 min caused minimum surface roughness of 0.066 µm during magnetic abrasive finishing of the brass plate. The percentage contribution of input parameters has been reported. Subsequently, the optimum results were obtained using multi-objective optimization techniques of grey relational analysis, and results were also validated using experimentation.

Heterostructured materials have a superior combination of strength and ductility, due to their ability to produce hetero-deform induced (HDI) strengthening and hardening. Therefore, achieving high HDI strengthening and hardening is the primary goal for designing heterostructures. Here we report a dual heterostructure in brass that consists of the heterogeneous lamella and gradient structure, fabricated by rolling, partial annealing, and rotationally accelerated shot peening (RASP). The dual heterostructures are able to generate extra interfaces of heterogeneity compared to the single heterostructures, which could lead to higher HDI strengthening and hardening, and a more superior combination of strength and ductility. This finding presents a new pathway to designing heterostructures in metallic materials.

It has become known that copper alloys are commonly used in heat exchangers and other marine industries. Although copper-nickel alloys have better properties than copper-zinc alloys in general, they are very expensive. The current research aims to give the alloy to give brass alloy (the cheapest alloy) superior properties in order to improve its performance and prolong the life of its use in the most important parts of the heat exchangers (pipes). Casting and heat treatment elements were used, and casting was carried out in a manner that ensures that the grains were softened to improve the properties. Tests were conducted to evaluate the performance of alloys such as hardness, oxidation and thermal shock. The effect of temperature and thickness of the oxide layer on the oxidation behavior was also studied. The results showed a significant increase in the thermal shock resistance, a positive change in the oxidation behavior, in addition to a significant improvement in the plasticity and adhesion of the oxide layer.

This research presents the numerical and empirical efforts to investigate the effect of friction stir welding (FSW) parameters on the weld temperature, weld strength, and weld hardness for novel brass known as yellow brass 405-20. The numerical approaches used to measure the weld temperature and weld strength were studied for the first time for yellow brass 405-20 and their validations via empirical studies. Two numerical models were simulated including transient thermal analysis and static structural analysis. Thermal distribution leading to maximum weld temperature during FSW of yellow brass was investigated via both simulations and experiments. Moreover, the ultimate tensile strength, namely the weld strength, was measured numerically and validated from its empirical counterpart. Finally, weld hardness was measured empirically to explore the joint health. A maximum temperature of 598 °C was recorded, which was much below the melting point of brass. Joint strength of 228 MPa was observed, which is 83% of the base brass strength. Microscopic examination of the weldment revealed the underlying mechanisms of less weld strength as compared to the parent brass material strength.

A tool-workpiece gap during the electrochemical discharge machining (ECDM) process is a critical parameter for successfully fabricating microchannels using line-array tool electrodes. Tool wear during the ECDM process increases the tool-workpiece gap and result in non-uniform array microchannel depths or intermittent machining due to reduced heat flux transferred into the workpiece. Hence, proper selection of a tool material that results in uniform tool-tips height/tool-workpiece gap for a longer machining time is essential, especially for the line-array tool electrodes. In this article, the tool wear behaviour of four different materials, i.e., brass, SS304, molybdenum, and tungsten, during fabrication of longer (>15 mm) and deeper (>200 μm) array microchannels using multi-pass ECDM process is reported. The tool wear behaviour at varying machining time/pass numbers was investigated, keeping all other process parameters constant. The experimental results found that the brass electrode's wear rate was relatively faster, and the line-array tool electrode becomes unusable for the ECDM process after 15 min of total machining time. The wear behaviour of molybdenum and tungsten tool materials was similar and resulted in intermittent or no microchannels formation after 35 min of machining time. At the electrolyte-air interface, necking of the tips and subsequent breaking at different machining times was observed for the brass, molybdenum, and tungsten tool materials. Comparatively uniform tips height, microchannel depths, and negligible necking were observed for the SS304 tool electrode after 65 min of machining time. Therefore, SS304 is a suitable tool material for fabricating longer and deeper array microchannels using the multi-pass ECDM process. Moreover, the fabrication of a dual serpentine flow field was demonstrated in the glass workpiece using customized SS304 line-array tool electrodes.

This article aims at presenting the model of the mass loss of a brass sample in ultrasonic cavitation field in saline water. The experiments done for data collecting was performed in three scenarios. In the first one, the high frequency generator worked at three power levels - 80 W, at the second one - at 120 W, and in the third one - at 180 W. The Model has been built using the series of the mass loss on surface.

Cet article analyse la façon dont la production pétrolière a reconfiguré les identités communautaires dans le delta du Niger au Nigeria. Il s’intéresse notamment à deux localités en milieu rural et urbain, à savoir l’île de Brass, sur la côte Atlantique, et Okrika, dans une banlieue de Port Harcourt. L’article montre que la ruée sur l’or noir a produit de façon contradictoire un double phénomène de fragmentation et de concentration des pouvoirs entre les mains des chefferies coutumières. L’extraction d’hydrocarbures n’est cependant pas le seul facteur qui a précipité cette « pétrochimie ethnique ». Pour apprécier la crise du delta, il convient aussi de prendre en compte les révoltes de la jeunesse, de pair avec l’urbanisation de la région et l’érosion du contrôle social des autorités traditionnelles dans le contexte d’un État prédateur. This article analyses how oil production has affected collective identities in the Niger Delta of Nigeria. It focuses on two cases: rural Brass Island (on the Atlantic Coast) and urban Okrika (a suburb of Port Harcourt). The article shows that the oil rush produced contradictory patterns of fragmentation and concentration of power in the hands of so-called customary chiefs. Yet the extraction of mineral resources is not the only factor contributing to communal conflict. Also relevant are youth rebellion, urbanization, and the weakening of social control by traditional authorities in the context of a predatory state.

Bu çalışmada, CW724R pirinç malzemesinin tornalamasında yüzey pürüzlülüğünü etkileyen faktörlerin deneysel optimizasyonu incelenmiştir. Çalışmada kesme hızı, talaş derinliği ve ilerleme parametreleri göz önünde bulundurularak Taguchi L9 deneyi gerçekleştirilmiştir. Deney sonuçlarının değerlendirilmesinde S-N değerleri esas alınmıştır. Çalışmada üç farklı kesme hızı, üç farklı talaş derinliği ve üç farklı ilerleme hızı seçilmiştir. Deneyler CNC torna tezgâhında dik ve kuru kesme şartlarında ve karbür uç kullanılarak gerçekleştirilmiştir. Çalışmada ortalama yüzey pürüzlülüğü (Ra) değerleri ölçülmüştür ve Taguchi tasarımında sinyal gürültü değerleri tespit edilmiştir. Elde edilen sonuçlara göre ilerlemenin yüzey pürüzlük değeri üzerinde etkili olduğu görülmüştür. En yüksek yüzey kalitesi değeri (en düşük Ra) 181 m/dak kesme hızında, 0,025 talaş derinliğinde ve 0,08 mm/dev ilerleme şartlarında elde edilmiştir., In this study, experimental optimization of factors affecting surface roughness in turning of CW724R brass material was investigated. In the study, Taguchi L9 test was carried out considering cutting speed, depth of cut and feed parameters. S-N values were taken as basis in the evaluation of the test results. Three different cutting speeds, three different depths of cut, and three different feed rates were selected in the study. The experiments were carried out on a CNC lathe under vertical and dry cutting conditions and using carbide inserts. In the study, the average surface roughness (Ra) values were measured and the signal noise values were determined in the Taguchi design. According to the results obtained, it was observed that the feed rate was effective on the surface roughness value. The highest surface quality value (the lowest Ra) was obtained at 181 m/min cutting speed, 0.025 depth of cut and 0.08 mm/rev feed conditions.

L’imitation de la dorure véritable par le biais d’un vernis transparent et coloré - ne contenant aucune particule d’or - est une pratique fréquente au XIXe siècle sur les bronzes d’ameublement. L’attention portée à ces revêtements découle de deux problématiques inextricablement liées : l’absence d’une étude historique approfondie permettant de déterminer leur possible intérêt patrimonial, les bronzes vernis étant relégués jusqu’à présent au second plan dans l’historiographie des bronzes décoratifs français et, d’autre part, la conservation des vernis qui pourrait être argumentée grâce aux résultats d’une telle analyse. Afin d’apporter des réponses, une recherche interdisciplinaire à partir de sources textuelles et matérielles a été menée. Elle se veut comparative, puisque le vernissage doit se mesurer aux techniques de dorure véritable, elles-mêmes évolutives, que l’on cherche à imiter. Le premier axe retrace l’origine de cette pratique et l’évolution qu’elle subit du point de vue des acteurs impliqués, des matériaux, outils, gestes et procédés employés. Le second axe traite de la place du bronze verni au sein de l’économie française et de la concurrence livrée en la matière avec les pays voisins, notamment l’Angleterre avec un regard particulier sur la complémentarité et la concurrence des techniques électrolytiques émergeant sous la monarchie de Juillet et leur impact possible sur la pratique de vernissage. Enfin, nous abordons la question de la typologie des objets et de la clientèle à laquelle s’adressent les bronzes vernis en clôturant cette étude sous l’angle de l’évolution du goût et son incidence possible sur la manière de réaliser ces épidermes trompe-l'œil. The application of transparent tinted varnishes – devoid of gold particles – on decorative bronzes to mimic gilding was a common practice during the 19th century. The stimulus for this work is the fact that conservators must frequently deal with these fragile surface coatings which are often difficult to identify. Few studies have been conducted, and these so-called gold lacquers occur only rarely in the historiography of french decorative bronzes. To investigate the role of these coatings in the history of 19th century bronzes, this interdisciplinary work was conducted using both written and material sources. We first tried to analyze the origin of bronze varnishing and its possible evolution from the point of view of the actors involved, the materials, tools, gestures and processes used. The second part of the study is concerned with the role of varnished bronze in the french economy, and the concurrence with neighbouring countries, especially England. In addition, we analyzed both the complementarity and competitiveness of electrolytic techniques which arose during the July Monarchy, and their possible impacts on the varnishing practice. We conclude with an examination of the various varnished bronze typologies and the market for them and consider the evolution of tastes and the possible consequences on creating these trompe-l’œil finishes.

Metal matrix composites (MMCs) are materials in which metals are reinforced with other materials preferably of lower cost to improve their properties. In this present study, Brass /Coconut Shell Ash powder (CSAp) composites having 0%, 5%, 10% and 15% weight CSAp were fabricated by stir-casting method. The tensile strength of the MMCs is in the order 15% > 10% >5% > 0% of CSAp. Hardness of the MMCs increases slightly with increase in the percentage body weight of CSAp, in the order 15% > 10% >5% > 0% of CSAp. The highest impact energy of 61 J was obtained for 5% CSAp. However, significant improvement in tensile strength and hardness values was noticeable at the 15%. Scanning Electron Microscopy (SEM) analysis of the MMCs shows dendritic structures formation, the reinforcing particles (CSAp) are visible and clearly delineated in the microstructure. Hence, this study has established that reinforcing brass matrix with coconut shell ash particles can result in the production of low cost brass composites with enhanced tensile strength, hardness and impact energy values.

The objectives of this paper are to use micro-X-ray fluorescence spectrometry (μ-XRF) and portable X-ray fluorescence spectrometry to specify the quality and element percent content of Sasanian and Parthian artwork samples: glasses, metals, and ceramics found in various regions of the Garmian area to determine and characterize the element and material compositions of the studied samples. The metallic models (L, M) are made of iron, (O) brass, (N.R) bronze, and (W, Y) silver, according to our findings. Soda ash makes up the majority of the glass samples (Si, Na, Ca>1%, MgO, K2O>1%). Sample J might be soda-lime glass because of the low Mg and K content (

The present study aims to reveal behaviors of leaded brass as it is exposed to the synergetic effect of corrosion and cavitation erosion. The specimens were submerged in seawater for ultrasonic cavitation erosion experiments. The cumulative mass loss, surface microstructure and three-dimensional surface morphology were analyzed to characterize the time-dependent damage of the specimens. For comparison, cavitation erosion in deionized water was investigated. The results show that the mass loss of leaded brass in seawater is much lower than that in deionized water, and the trend is distinct after 45 min of cavitation erosion. Four characteristic stages of ultrasonic cavitation erosion are evidenced in seawater. In deionized water, only the acceleration stage is recognizable. The effect of cavitation erosion proves to be more significant than that of corrosion for the surface damage. In seawater, cavitation erosion is delayed by the protective passivation film with the main constituent of Cu2O, which is generated and disintegrated repeatedly. The corresponding surface roughness is low. In deionized water, the specimen surface is rapidly damaged under the exclusive effect of cavitation erosion.

Статья посвящена уникальному факту использования редкого сплава -латуни для изготовления деталей конского снаряжения позднесарматского времени. Комплексный анализ археологического материала включал исследование морфологии вещей и вариаций химического состава металла изделий. Полученные данные были сопоставлены с результатами анализа сплавов боспорских монет конца II в. н. э. Это позволило предположить три возможных варианта поступления уздечных наборов из редкого иноземного материала латуни к варварам Северного Причерноморья: 1) путем изготовления наборов в местной варварской среде мастерами-литейщиками с использованием переплавленных боспорских латунных монет; 2) производство снаряжения в мастерских Боспора для даров представителям варварской знати; 3) амуницией с латунными принадлежностями снабжались варварские всадники, находившиеся на службе у боспорских царей. The paper explores a unique fact of using a rare alloy, i.e. brass, to make horse trappings details in the Late Sarmatian period. The comprehensive analysis of the archaeological material included a study of the artifact morphology and variability of the chemical composition of the metal the artifacts were made from. The data obtained were compared with the data on the analyzed alloys used to make Bosporan coins at the end of the 2nd century. This comparison suggested three possible variants explaining how the barbarians living in the North Pontic region got hold of the bridle sets made from rare material, i.e. brass, produced in other lands: 1) the sets were produced in the local barbarian environment by craftsmen-casters with the use of remelted Bosporan coins; 2) the horse trappings were produced in Bosporan workshops to be given to barbarian elite as gifts; 3) ammunition with brass items was given to barbarian horse riders who served to the Bosporan kings.

The 17th-century manuscript M7709 (held in the Matenadaran, Yerevan, Armenia) includes an Armenian copy of the History of the City of Brass, to which an unknown scribe has added short poems about Alexander the Great. The first of three articles that together present the Alexander poems of M7709 in full, with English translation, for the first time, this article introduces the manuscript and considers the first six poems: the seduction of Olympias, and Alexander’s encounter with plant-men at the edge of the world. It adds commentary on the poems’ relationship to the corresponding part of the History of the City of Brass on each page, proposing textual reasons why the scribe added the poems where he did. Across the three articles, this commentary delves into textual relationships beyond the pages of M7709, linking the Armenian History of the City of Brass, Alexander Romance and other texts and traditions, to show how this manuscript is situated amid wider networks of circulating literature. As a microhistorical study, it seeks to provide illumination into the macrohistory of medieval and early modern literature in and beyond the Caucasus.

The drinking water supply system in many high rise buildings in densely populated cities consists of a complex labyrinth of copper pipes and brass fixtures (valves, meters, couplings). Lead contamination in these non-lead pipe systems can occur due to the presence of lead-soldered connections, and lead containing brass fixtures. The prediction of lead concentration characteristics of random daytime (RDT) samples in these high rise buildings has hitherto not been studied. The stochastic variation of lead concentration of RDT samples is studied by a coupling of 3-D and 1-D models and the Monte-Carlo Method. A 3-dimensional CFD model based on an equilibrium concentration ( E 0 ) approach is used to simulate the leaching process from different lead sources. With the calibrated E 0 for different materials obtained from leaching experiments, the lead source strengths of leaded components in a water supply chain can be predicted by the 3D model as a function of stagnation time. Using the predicted distributed lead sources, the transport and mixing of lead in the turbulent pipe flow can be accurately simulated by a 1D advection–diffusion model. Using the Monte-Carlo method, a large number of simulations of consumer tap water Pb concentrations is performed using randomly sampled stagnation time, inter-use time, and flushing time. The computations are performed for two representative prototypes: (i) a full scale lead contaminated water supply chain; and (ii) a chain with only clean pipes and brass fixtures. The effect of stagnation time and flushing time before water use on tap Pb levels are investigated. The predicted range and distribution of RDT sample concentrations are validated by a three-year field data set (2017–2020) of the Hong Kong Water Supplies Department.

The wear phenomenon is one of the essential factors in the failure of industrial components. Therefore, it is vital to investigate the wear behavior of engineering materials and metal matrix composites (MMC). In this article, Al 1050/Brass (70/30)/Al 1050 composite sheets were fabricated using the accumulative roll bonding (ARB) process. The ARB process was performed at ambient temperature without any heat treatment between the cycles in 5 passes. Mechanical properties, fracture surface, and wear behavior of the specimens were also measured. The tensile strength of the Al/Brass/Al sandwich sample is higher than the primary aluminum and less than the original brass. As the number of ARB cycles increases, the tensile strength and elongation changes have no significant trend. The highest ultimate tensile strength was obtained in the first cycle at 288 MPa, which is about 3.5 times the primary aluminum. The highest hardness was also obtained for aluminum and brass after the end of the fourth cycle. Pin-on-disk wear tests were applied with two different forces on specimens, and as an important achievement, the results show that by using Al/Brass/Al composite can increase the wear resistance of aluminum. Worn surface morphology and wear debris of samples were also examined by scanning electron microscopy (SEM). The optical microscope's checking of the layers shows that the brass layer is completely crushed in the aluminum field from the second cycle onwards. Fracture surface images of the samples also show both ductile and brittle fractures.

The obstacle faced during the fatigue test is the waiting time which is quite long and inefficient, especially for test specimens made of ductile metal with waiting times of up to several days. The research method includes reducing the specimen radius to obtain a flexural stress approaching 400 MPa which was originally 229 MPa from a radius of 254 mm to 240 mm with the results of turning the original specimen obtained a minimum diameter of 8.6 mm is reduced to 7.3 mm at a maximum loading of 10 kg. Results of the research are brass specimens C3604BD type with a minimum diameter of 8.6 mm at a flexural stress of 298 MPa showing a fatigue life of 2455546 cycles with a test duration of 1754 minutes and a minimum specimen diameter of 7.3 mm at a flexural stress of 299 MPa showing a fatigue life of 684311 cycles with a test duration of 489 minutes which means that with a minimum specimen diameter of 7.3 mm the fatigue life is 3.59 times shorter than a minimum specimen diameter of 8.6 mm. Meanwhile, for aluminium AA1101 type with a minimum specimen diameter of 7.3 mm at a flexural stress of 182 MPa, the fatigue life is 422117 cycles with a test duration of 278 minutes and with a minimum specimen diameter of 8.6 mm at a flexural stress of 183 MPa, the fatigue life is 389232 cycles with a test duration of 302 minutes which means that with a minimum specimen diameter of 7.3 mm the fatigue life is 1.05 times shorter than the minimum specimen diameter of 8.6 mm or almost the same.

Purpose: Acrylic denture base tends to fracture frequently during their service due to poor strength. The surface roughness of denture base is a critical property because denture base with rough surface will cause accumulation of food particles ,thereby leading plaque retention . Microbes such as candida albicans are seen inhabitating the surface. Materials and Methods: Conventional heat cure denture base reins(DPI) and heat cure denture base resin with incorporation of 15wt% aluminium oxide was studied in two groups with 20 samples each. A mold of size 65 mm × 10 mm × 3 mm (ISO Standard) was obtained by investing brass rectangles. About forty specimens were prepared. Specimens were divided into two groups (n = 20) coded A and B. Group A was the control group (n = 20) without addition of aluminum oxide. Group B was the experimental group (n = 20) with addition of 15 wt % aluminum oxide. All the specimens were stored in distilled water for 14 days. The flexural strength was measured using a three-point bending test in a universal testing machine, and the surface roughness was measured using contact-type profilometer. Results: Incorporation of 15wt% aluminum oxide leads to a significant increase in flexural strength and surface roughness of conventional heat-cure denture base resin.

With the aim of leaving a smaller ecological footprint and to develop fuels which will change the energy needs of the future in a sustainable manner, the present study aims at investigating the corrosion phenomenon of brass using biodiesel fuel from cast-off cooking oil (CCO) in various blending ratios with commercial diesel (5 %, 10 % and 20 %) on brass. The mechanism of corrosion of brass in biodiesel has not been adequately investigated, and in the literature there is still a drop in the knowledge of the corrosion of brass from which many diesel engine parts are made. The corrosion rate of brass has been evaluated by mass loss and electrochemical methods. As a complementary technique, conductivity was monitored before and after each test. Surface morphology was examined by optical microscope. The surface morphology of brass samples in NaCl was coated in dark deposits that indicated corrosion. Some pitting was found in O99, and no significant change was found in oil-diesel blends. There is a positive correlation between the corrosivity and conductivity of the test media. The wettability studies also assisted in determining the non-corrosive nature of biodiesel.

Purpose The purpose of this study was to investigate the polyacrylic polymer/Al2O3 as a new nanocomposite coating to protect brass and Al-bronze in 3.5% NaCl and the role of alumina formulation on their protection efficiency Design/methodology/approach The corrosion efficiency of the nanocomposite coating (NCC) was evaluated by open circuit potential and electrochemical impedance spectroscopy (EIS). Findings The protection efficiency was more in the case of Al-bronze even for the same formulation of alumina NCC indicated the Cu substrate contribution. The Cu oxides in alloys and Al2O3 from the NCC and Al-bronze were responsible for this protection. Originality/value All the techniques supported each other, the presence of alumina was responsible for the corrosion protection efficiency.

Evolution of microstructure, texture, and hardness of the Al-Cu-Mg alloy was investigated by using scanning electron microscopy, electron backscatter diffraction, transmission electron microscopy, and x-ray diffraction. Results have shown that the hardness and Brass texture intensity of the Al-Cu-Mg alloy can be enhanced during the annealing process at 240-385 °C. The hardness enhancement of the alloy can be attributed to the fine-grain strengthening; the enhancement of the Brass texture intensity of the alloy is related to the polygonization of the deformed grains with Brass orientation. In addition, the evolution path of the Brass texture evolving into recrystallization texture during annealing can be summarized as follows: Brass texture → Goss texture → R-Goss texture → Cube texture.

Brass melting slag (20.38 wt.% Zn) was leached in sulfuric acid with concentration of (50 + 80) g/l H2SO4, leaching temperature of (30 + 60) °C for (30 + 120) min. The optimized conditions for 94.16% Zn extraction from brass melting slag were found as 70 g/l H2SO4, room temperature and 90 min. The leaching solution was purified by removal of Fe through Fe(OH)3 precipitation when adding ZnO to adjust pH value of 5. The solution was continuously cemented by Zn metal at 60 °C for 60 min to obtain Cu metal with high purity of 99 wt.% Cu. The purified solution with 37.64 g/l Zn was modified by Na2C03 to have pH value of about 6 and precipitation of ZnC03 (94.14 %).

Purpose This paper aims to increase the knowledge of the run-in process of lubricated contacts in hydraulical pumps. When performing EHL simulations of tribological contacts, the surface influence needs to be taken into account. This experimental measurement wants to investigate the amount of change of the flow factors in the first hour of run of tribological contacts. Design/methodology/approach An experimental test bench is used to run-in several samples. After several minutes of running, samples are removed and the surface structure is captured using a digital microscope. With the measured data, flow factors are calculated. Findings The findings were clear that flow factors are highly direction-dependent, especially shear flow factors in radial directions experience almost no change. Overall, influence of the surface structure of up to 30% compared to a flat surface can be registered. Originality/value This paper helps to choose application-oriented values for the simulation of tribological contacts.

In this paper, forming limit diagram (FLD) of aluminum/brass two-layer sheets through an incremental forming process (ISF) was studied numerically and experimentally. At first, the two-layer aluminum 1050/brass (65% copper) sheets were fabricated using the roll bonding process. Also, the finite element simulations of the incremental forming process with ABAQUS software were utilized to predict the FLD. For this purpose, the criterion of the second derivative of the equivalent plastic strain was used to predict fracture. Finally, the numerical simulation results were compared with the experimental results. For instance, comparing experimental and numerical FLD0 values for the formed samples with forming angle 62.5-degree showed a 7% difference. However, the difference was negligible, and numerical simulation results could be used with an appropriate reliability coefficient. The effect of sheet arrangement towards tools was then investigated. It finds out from the experimental results that the formability of the Brass/Al (brass was up layer and aluminum was bottom layer) was more than the Al/Brass (aluminum is up layer and brass is bottom layer). In the following, the ISF parameters such as forming limit angle, step-down, and thickness distribution were investigated.

The structure, morphology, microhardness, and tear strength of the L63 brass–36N invar welded joint fabricated by explosive welding are investigated. The shape of the joint interface is wavy with stable parameters (amplitude, length) for the chosen welding parameters and plate thicknesses (12 mm for brass, 8 mm for invar). CuZnFeNi cast inclusions with a microhardness of up to 500 HV are detected in wave crests and troughs. The microhardness of the near-weld zone on the brass side is found to be 50% higher than that of the base material, and the microhardness on the invar side is higher by 20%. The tear strength of the joint is 550 MPa, which is higher than the strengths of the initial materials.

The purpose of this study was to see if Cymbopogon schoenanthus aerial extract (CSA extract) could reduce the corrosion of aluminum brass in acid cleaning solutions in the distillation plant. For this assessment, measurements of weight loss and polarization technique have all been used. We discovered that at 250 ppm, the efficiency of CSA extract was excellent (97%). Polarization assessments confirmed that the organic compounds in CSA extract were effective mixed-type corrosion inhibitors. HPLC and FTIR analysis were used to explore the key chemical components of CSA extract. CSA extract caused the corrosion process to have a higher energy barrier. Observations of SEM and FT-IR spectra confirmed that CSA extract prevents corrosion attacks at the aluminum brass’s surface.

Background: Alginate impression material is the irreversible hydrocolloid material that is widely used in dentistry. The contact time between alginate and gypsum cast could have a detrimental effect on the properties of the gypsum cast. The objective of this study is to evaluate the impact of various contact time intervals of Alginate impressions & type III dental stone on surface properties of stone cast. Materials and Methods: Time intervals tested were 1hour, 6 hours and 9 hours. Surface properties of stone cast evaluated were surface detail reproduction, hardness and roughness. Surface detail reproduction was determined using cylindrical brass test block in accordance with ISO 1563. Surface roughness was measured by profilometer and hardness was measured by Durometer (Shore D). Results: The detail reproduction showed significant difference (P

Spraying process is an alternative way to replace Chromium electroplating technique which presents industrial, economic and ecological disadvantages. The investigated work aims to develop non-usual coatings to protect the brass substrate and to ameliorate the faucets performance. Several materials with the viable deposition capability and with the excellent properties have been processed through spraying process, including polymers, thereby creating the fluorinated-ethylene-propylene and the poly-tetra-fluoro-ethylene coatings. The painting process is one of the innovative and the simple spraying techniques with growing scientific interests and industrial applications in the field of faucets. This method offers corrosion protection and results in increases in mechanical and physical durability and wear resistance. Experiments subsequently confirmed the successful deposition of polymer suspensions onto the brass substrate. Based on the results, it was determined that both coatings exhibit a hydrophobic character owing the low values of surface energy obtained and the FEP coating presents the best friction results. This review extensively exploits the latest developments in the experimental analysis of spraying processes. Coating formation, characterization of deposit development, description of process parameter and principles, are summarized.

The copper based alloys Al-bronze and α-brass containing each of 10wt% aluminum and zinc were prepared by casting. Afterwards, the specimens were cold-rolled with various percentages of deformation and the cold-rolled samples were aged subsequently at the varied time for four hours and temperatures ranging up to 500°C. Samples underwent characterizations by microhardness testing, electrical resistivity, optical properties, differential scanning calorimetry as well as microstructure analysis using an optical microscope. The results showed that the hardening of Cu-based alloys was taken place due to solid-solution hardening. Al addition accelerated the hardness through ageing due to the formation of various intermetallic copper aluminites into the aged alloy which was hard and brittle in nature. The resistivity decreased marginally through heat treatment due to the stage of stress relieving, recovery, precipitation coarsening as well as recrystallization and increased for arranging different intermetallics into the alloys. The microstructural study revealed that the cold rolled alloys content the different phases of elongated grain at the rolling direction. Meanwhile higher ageing temperatures at 500°C for one hour led to recrystallization and grain growth especially in pure copper and Cu-10Zn alloys.

The article examines the breaks of thin brass‑plated wire for metal cord and high‑pressure hoses of the “sparking” type and the causes of their formation. The wire was manufactured in OJSC “BSW” – he Management Company of the Holding” BMC “ in the conditions of steel‑wire workshops. The appearance and microstructure of breaks of thin brassplated wire of the “sparking” type are investigated. As a result of the analysis of the appearance and microstructure of the breaks, it was assumed that surface defects are formed on the brass‑plated wire – billet during the welding connection in the jaws of the welding machine during annealing. To confi m this, experiments were carried out with the implementation of welded joints of brass – plated wire‑blanks in wet drawing areas, the appearance and microstructure of the obtained samples of welded joints were studied.As a result of experiments and metallographic studies, the assumption was confirmed that local defects such as “cauterization from sparking” on the surface of the workpiece wire are formed during welding during the annealing operation, it was established that the cause is a violation of contact between the wire and the pressure jaws of the welding machine, wear of the pressure jaws. Photos of the defect, a description of its appearance and microstructure are given.Based on the obtained studies, a number of measures were carried out aimed at eliminating the causes of this defect.

High strength and large ductility of existing Mn-containing brass alloys need to be further improved when used as slippers of friction-pair materials, which could be achieved by tuning alloy composition and thermomechanical treatments appropriately. The present work optimized the amount of minor-alloying elements M (M = Mn, Fe, Si) in Cu-Zn alloy via a cluster formula approach and then investigated the microstructural evolution of the designed alloy with different thermomechanical treatments. As-cast alloy ingots were solid-solutioned at 1093 K (820 °C) for 3 h, hot-rolled at 923 ~ 1023 K (650 ~ 750 °C), and then aged at 673 ~ 723 K (400 ~ 450 °C) for 1 ~ 2 h, respectively. It is found that the alloy matrix consists of the main FCC-α phase plus a small amount of BCC-β and M5Si3 phases, among which the M5Si3 exhibits three types of primary, fine, and nano-scaled particles. The mechanical property varies with the thermomechanical treatments due to diverse microstructures (especially the morphology of M5Si3 particles), in which the high strength (σUTS > 580 MPa) and large ductility (δ = 16.3 ~ 29.4%) could be achieved simultaneously in 673 K (400 °C). The optimal matching of high strength and large ductility makes the current alloy more suitable as an alternative slipper material. The strengthening effect was further discussed in light of various strengthening mechanisms, and the calculated strength increment is well consistent with the experimentally measured yield strength.

This paper discusses cold sink drawing for production of square-cross-section pipe/tube and the effect that billet material has on the energy and power parameters describing the drawing process and on the billet drawing speed. Pipe/tube made from L63 brass, 10 steel, and VT1–0 technical-grade titanium were considered. We develop a computer model with an objective description of the actual process, and performed a full-scale experiment that verified the computer model was appropriate and reproduced the results of the mathematical simulation. The mathematical simulation was performed using the ANSYS and DEFORM finite-element software packages. This study resulted in process recommendations for process equipment users and developers that can be used to predict drawing results.

The preservation of cultural heritage monuments and artifacts requires the development of methods to produce water-repellent materials, which can offer protection against the effects of atmospheric water. Fluorosilanes are a very promising class of materials, as they act as precursors for the formation of low surface energy polymer networks. 1H,1H,2H,2H-perfluorooctyl-triethoxysilane is applied on marble, wood and the surfaces of other materials, such as glass, silicon wafer, brass, paper and silk. According to the measurements of static water contact angles, it is reported that superhydrophobicity and enhanced hydrophobicity are achieved on the surfaces of coated marble and wood, respectively. Hydrophobicity and hydrophilicity were observed on the treated surfaces of the other materials. More important, water repellency is achieved on any hydrophobic or superhydrophobic surface, as revealed by the very low sliding angles of water drops. The study is accompanied by colorimetric measurements to evaluate the effects of the treatment on the aesthetic appearances of the investigated materials. Finally, the capillary absorption test and a durability test are applied on treated wood and marble, respectively.