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Duplex stainless steels are being used on applications that require, especially, high corrosion resistance and overall good mechanical properties, such as the naval and oil-gas exploration industry. The components employed in these industries are usually obtained by machining, however, these alloys have low machinability when compared to conventional stainless steels. In this work, a study of the wear developed when milling duplex stainless-steel, LDX 2101, is going to be presented and evaluated, employing four types of milling tools with different geometries and coatings, while studying the influence of feed rate and cutting length in the wear of these tools. Tools used have been provided with two and four flutes, as well as three different coatings, namely: TiAlN, TiAlSiN and AlCrN. The cutting behavior of these tools was analyzed; data relative to the cutting forces developed during the process were obtained; and roughness measurements of the machined surfaces were executed. The tools were then submitted to scanning electron microscope (SEM) analysis, enabling the identification of the wear mechanisms that tools were subjected to when machining this material, furthermore, the early stages of these mechanisms were also identified. All this work was done with the goal of relating the machining parameters and cutting force values obtained, identifying, and discussing the wear patterns that were observed in the coating and tools after the milling tests, providing further information on the machining of these alloys., The present work was done and funded under the scope of the project ON-SURF (ANI | P2020 | POCI-01-0247-FEDER-024521, co-funded by Portugal 2020 and FEDER, through COMPETE 2020-Operational Programme for Competitiveness and Internationalisation. F.J.G. Silva also thanks INEGI-Instituto de Ciência e Inovação em Engenharia Mecânica e Engenharia Indústria, due to its support. The authors would like to thanks to Dr. Rui Rocha from CEMUP (Porto, Portugal), due to his active collaboration in getting the best SEM pictures, helping with his critical analysis of some phenomena. Authors also would like to thank Ing. Ricardo Alexandre due to is extremely important role in providing all the coatings through TEandM company, and also Ing. Nuno André, for providing the substrate material and uncoated tools through the Inovatools company.

Abrasive wear is a wear mechanism that results in a loss of material from the interaction of a surface with hard particles. This type of wear is frequently found in the surface of machining tools. Microscale abrasion equipment is often used to characterize the resistance to abrasive wear of a surface. The different parameters able to control micro-abrasion wear tests, such as ball rotation, sliding distance between ball and surface sample, abrasive slurry concentration, normal load acting on the sample, and abrasive flow rate over the sample, have been widely studied. The combination of different variables, including sliding distance, concentration of abrasive particles, their hardness, and size of abrasive particles, promotes the transition between two-body, three-body, or mixed abrasive wear modes. However, the influence of the ball surface on the dragging of abrasive particles, which is reflected in the wear modes, is still poorly studied. One of the variables possible to control and less studied is the influence of the ball surface texture on the dragging of abrasive particles in micro-abrasion wear tests. This work intends to correlate the effect of different testing times (500, 1000, and 1500 cycles) and different concentrations of 3 μm Al2O3 abrasive slurry (25, 35, and 45 g/100 mL) on the micro abrasion resistance of a TiN thin coating film, using balls of AISI 52100 steel whose texture and roughness were prepared by 60 s chemical etching. The rotation speed of each test was 80 rpm, applying a normal load of 2 N. Subsequently, the craters were carefully analyzed using SEM to evaluate the transition of the wear mode as a function of the applied load, the abrasive particle concentration, and the sliding distance. The textured ball tracks were observed via SEM to assess the particle dynamics. The results showed that, contrarily to what is reported in the literature regarding wear modes where rolling is promoted with increasing abrasive concentration, in this work grooving took place instead. This is a result of the rough balls use in the experiments which, due to the embedment of abrasive particles in the ball grooves, promotes the abrasion mechanism. The higher the abrasive concentration, the higher the grooving mechanism, since more particles are available to scratch the surface.

The injection of light alloys is an activity that requires a high effort on the part of Engineering to maintain its competitiveness. Due to the temperatures used, the wear of the components connected to this manufacturing process is quite intense, requiring a constant updating effort. This work was developed with a view to solving problems related to the excessive wear of injection nozzles used in the die casting process, and corresponding electrical resistances, with a view to increase its lifetime and improve the competitiveness of the process in the injection of low-cost parts in zamak for the automotive industry. To study and solve the problems of premature wear of the injection nozzles, the action-research method was used, which, through several iterations, allowed to arrive at an improved design of the nozzle, as well as the corresponding electrical resistance, thus increasing the life span of these components, also improving safety around the process and generating knowledge that can be transferable to other similar situations., The authors would like to thank Mr. Mário Cardoso from FicoCables, Lda. for his continuous support, proving interesting challenges for applied research. Authors would like to thank Ing. Fátima Andrade due to her help in preparing the samples and collecting images in the optical microscope. Authors would also thank INEGI - Instituto de Ciência e Inovação em Engenharia Mecânica e Engenharia Industrial, Porto, Portugal, due to its continuous support.

Machining processes remain an unavoidable technique in the production of high precision parts. Tool behavior is of utmost importance in machining productivity and costs. Tool performance can be assessed by the roughness left on the machined surfaces as well as of the forces developed during the process. Depending on the machining process, different types of dynamometers may be adopted. This technique has often been used by numerous researchers in this area. This paper aims to make an overview of the different techniques and devices for measuring the forces developed in machining processes, allowing a quick perception of the advantages and limitations of each technique, through a literature research carried out using recently published works.

Huge constructions mostly contain different profiles to form a structure. These profiles can appear in different forms and sizes, but also the used materials can vary. For this case steel “T”-profiles are used. Before, the “T”-profiles were welded manually with conventional welding techniques. The novel design of a machine that can automatically laser-weld “T”-profiles of up to six meters in length is will be presented. The design of this equipment was done using AUTODESK software, FUSION 360. The machine presents a modular concept, containing four parts with different functions: the loading, the vertical centring, the welding, and the unloading. The loading and the unloading of the plates is performed manually with the use of a roller bridge. A lift system is designed to ease the loading of the plates and to clamp the vertical one after the loading is done. A centring system makes it possible to put the horizontal and vertical plates in the desired position. The clamps are wheels, so that the plates roll, and the clamps cannot interrupt the laser beam during the welding. A pressing system excludes possible gaps between the two plates in the welding zone. Extendable feet make it possible to level out the whole machine and the alignment is done with the use of low-cost brackets.

One of the most critical factors in producing plastic injection molds is the cost estimation of machining services, which significantly affects the final mold price. These services’ costs are determined according to the machining time, which is usually a long and expensive operation. If it is considered that the injection mold parts are all different, it can be understood that the correct and quick estimation of machining times is of great importance for a company’s success. This article presents a proposal to apply artificial neural networks in machining time estimation for standard injection mold parts. For this purpose, a large set of parts was considered to shape the artificial intelligence model, and machining times were calculated to collect enough data for training the neural networks. The influences of the network architecture, input data, and the variables used in the network’s training were studied to find the neural network with greatest prediction accuracy. The application of neural networks in this work proved to be a quick and efficient way to predict cutting times with a percent error of 2.52% in the best case. The present work can strongly contribute to the research in this and similar sectors, as recent research does not usually focus on the direct prediction of machining times relating to overall production cost. This tool can be used in a quick and efficient manner to obtain information on the total machining cost of mold parts, with the possibility of being applied to other industry sectors.

The machining process is still a very relevant process in today’s industry, being used to produce high quality parts for multiple industry sectors. The machining processes are heavily researched, with the focus on the improvement of these processes. One of these process improvements was the creation and implementation of tool coatings in various machining operations. These coatings improved overall process productivity and tool-life, with new coatings being developed for various machining applications. TiAlN coatings are still very present in today’s industry, being used due to its incredible wear behavior at high machining speeds, high mechanical properties, having a high-thermal stability and high corrosion resistance even at high machining temperatures. Novel TiAlN-based coatings doped with Ru, Mo and Ta are currently under investigation, as they show tremendous potential in terms of mechanical properties and wear behavior improvement. With the improvement of deposition technology, recent research seems to focus primarily on the study of nanolayered and nanocomposite TiAlN-based coatings, as the thinner layers improve drastically these coating’s beneficial properties for machining applications. In this review, the recent developments of TiAlN-based coatings are going to be presented, analyzed and their mechanical properties and cutting behavior for the turning and milling processes are compared.

PVD (physical vapor deposition) and CVD (chemical vapor deposition) have gained greater significance in the last two decades with the mandatory shift from electrodeposition processes to clean deposition processes due to environmental, public safety, and health concerns. Due to the frequent use of coatings in several industrial sectors, the importance of studying the chromium coating processes through PVD–sputtering can be realized, investing in a real alternative to electroplated hexavalent chromium, usually denominated by chromium 6, regularly applied in electrodeposition processes of optical products in the automotive industry. At an early stage, experimental tests were carried out to understand which parameters are most suitable for obtaining chromium coatings with optical properties. To study the coating in a broad way, thickness and roughness analysis of the coatings obtained using SEM and AFM, adhesion analyzes with the scratch-test and transmittance by spectrophotometry were carried out. It was possible to determine that the roughness and transmittance decreased with the increase in the number of layers, the thickness of the coating increased linearly, and the adhesion and resistance to climatic tests remained positive throughout the study. Thus, this study allows for the understanding that thin multilayered Cr coatings can be applied successfully to polymeric substrates regarding optical applications in the automotive industry.

Predictive maintenance is a key area that is benefiting from the Industry 4.0 advent. Recently, there have been several attempts to use Machine Learning (ML) in order to optimize the maintenance of equipments and their repairs, with most of these approaches assuming an expert-based ML modeling. In this paper, we explore an Automated Machine Learning (AutoML) approach to address a predictive maintenance task related to a Portuguese software company. Using recently collected data from one of the company clients, we firstly performed a benchmark comparison study that included four open-source modern AutoML technologies to predict the number of days until the next failure of an equipment and also determine if the equipments will fail in a fixed amount of days. Overall, the results were very close among all AutoML tools, with AutoGluon obtaining the best results for all ML tasks. Then, the best AutoML predictive results were compared with a manual ML modeling approach that used the same dataset. The results achieved by the AutoML approach outperformed the manual method, thus demonstrating the quality of the automated modeling for the predictive maintenance domain., This work was executed under the project Cognitive CMMS - Cognitive Computerized Maintenance Management System, NUP: POCI-01-0247-FEDER-033574, co-funded by the Incentive System for Research and Technological Development, from the Thematic Operational Program Competitiveness of the national framework program - Portugal2020.

Machining processes remain an unavoidable technique in the production of high-precision parts. Tool behavior is of the utmost importance in machining productivity and costs. Tool performance can be assessed by the roughness left on the machined surfaces, as well as of the forces developed during the process. There are various techniques to determine these cutting forces, such as cutting force prediction or measurement, using dynamometers and other sensor systems. This technique has often been used by numerous researchers in this area. This paper aims to give a review of the different techniques and devices for measuring the forces developed for machining processes, allowing a quick perception of the advantages and limitations of each technique, through the literature research carried out, using recently published works, The present work was done and funded under the scope of the project ON-SURF (ANI | P2020 | POCI-01-0247-FEDER-024521, co-funded by Portugal 2020 and FEDER, through COMPETE 2020-Operational Programme for Competitiveness and Internationalisation. F.J.G. Silva also thanks INEGI-Instituto de Ciência e Inovação em Engenharia Mecânica e Engenharia Industria, due to its support.

The milling process is one of the most used processes in the manufacturing industry. Milling, as a process, as evolved, with new machines and methods being employed, in order to obtain the best results consistently. Milling tools have also seen quite an evolution, from the uncoated high-speed steel tool, to the now vastly used, coated tools. Information on the use of these coated tools in recent scientific researches was collected. The coatings that are currently being researched are going to be presented, highlighting some novel advances in the nanocomposite and diamond coatings area, as these coatings are seeing a growing use in the industry, with very satisfactory results, with performance and tool-life increase. Wear mechanism of various types of coatings are also a popular topic on recent research, as the cutting behavior of these coated tools provides valuable information on the tool’s-life. Furthermore, analysis of these mechanisms enables for the selection of the best coating type for the correct application. Recently, the employment of coated tools paired with sustainable lubrication methods as seen some use. As this presents the opportunity to enhance the coated tool’s and the process’s performance, obtaining better results, in terms of better tool-life and better surface finish quality, in a more sustainable fashion, This research was funded by ON-SURF Project, grant number NUP POCI-01-0247-FEDER-024521.

Turning continues to be the largest segment of the machining industry, which highlights the continued demand for turned parts and the overall improvement of the process. The turning process has seen quite an evolution, from basic lathes using solid tools, to complex CNC (Computer Numerical Control) multi-process machines, using, for the most part, coated inserts and coated tools. These coatings have proven to be a significant step in the production of high-quality parts and a higher tool life that have captivated the industry. Continuous improvement to turning coated tools has been made, with many researches focusing on the optimization of turning processes that use coated tools. In the present paper, a presentation of various recently published papers on this subject is going to be made, mentioning the various types of coatings that have recently been used in the turning process, the turning of hard to machine materials, such as titanium alloys and Inconel, as well as the interaction of these coatings with the turned surfaces, the wear patterns that these coatings suffer during the turning of materials and relating these wear mechanisms to the coated tool’s life expectancy. Some lubrication conditions present a more sustainable alternative to current methods used in the turning process; the employment of coated tool inserts under these conditions is a current popular research topic, as there is a focus on opting for more eco-friendly machining options.

Duplex stainless steels are being used on applications that require high corrosion resistance and excellent mechanical properties, such as the naval and oil-gas exploration industry. The components employed in these industries are usually obtained by machining; however, these alloys have low machinability when compared to conventional stainless steels, usually requiring the employment of tool coatings. In the present work, a comparative study of TiAlSiN coating performance obtained by these two techniques in the milling of duplex stainless-steel alloy LDX 2101 was carried out. These coatings were obtained by the conventional direct current magnetron sputtering (dc MS) and the novel high power impulse magnetron sputtering (HiPIMS). The coatings were analyzed and characterized, determining mechanical properties for both coatings, registering slightly higher mechanical properties for the HiPIMS-obtained coating. Machining tests were performed with varying cutting length and feed-rate, while maintaining constant values for axial and radial depth of cut and cutting speed. The surface roughness of the material after machining was assessed, as well as the wear sustained by each of the tool types, identifying the wear mechanisms and behavior of these tools, as well as registering the flank wear values presented for each of the tested tools. The HiPIMS-obtained coating exhibited a very similar behavior when compared to the other, producing similar surface roughness quality. However, the HiPIMS coating exhibited less wear for higher cutting lengths, proving to be a better choice in this case, especially regarding tool life.

Copper-Beryllium alloys have excellent wear resistance and high mechanical properties, they also possess good electrical and thermal conductivity, making these alloys very popular in a wide variety of industries, such as aerospace, in the fabrication of tools for hazardous environments and to produce injection molds and mold inserts. However, there are some problems in the processing of these alloys, particularly when these are subject to machining processes, causing tools to deteriorate quite rapidly, due to material adhesion to the tool’s surface, caused by the material’s ductile nature. An assessment of tool-wear after machining Cu-Be alloy AMPCOLOY 83 using coated and uncoated tools was performed, offering a comparison of the machining performance and wear behavior of solid-carbide uncoated and DLC/CrN multilayered coated end-mills with the same geometry. Multiple machining tests were conducted, varying the values for feed and cutting length. In the initial tests, cutting force values were registered. The material’s surface roughness was also evaluated and the cutting tools’ edges were subsequently analyzed, identifying the main wear mechanisms and how these developed during machining. The coated tools exhibited a better performance for shorter cutting lengths, producing a lower degree of roughness on the surface on the machined material. The wear registered for these tools was less intense than that of uncoated tools, which suffered more adhesive and abrasive damage. However, it was observed that, for greater cutting lengths, the uncoated tool performed better in terms of surface roughness and sustained wear.

The structure of car seats is becoming increasingly complex, with mixing of wire conformation and plastic injection. The plastic over-molding process implies some labor, which can be reduced if novel solutions are applied in this manufacturing area. The handling of the wires used in car seats is the main problem identified in the process, wasting time both in the feeding and in the extraction of the molds used in the wire over-molding process. However, these machines are usually extremely compact and the free space around them is too short. In classic molding injection machines, there are just two half-molds, the female, and the male. In the over-molding process of wires used in car seats, three half-molds are used in order to increase the cycle time. Thus, to solve this problem, the classic robotic solutions are not appliable due to lack of space and elevated cost. This work describes the development of an automated solution able to handle the wires in both the feeding and the extracting phases of the production cycle, avoiding the traditional labor costs associated with this type of machine. Departing from an industrial need, the developed novel solution is described in detail and can be successfully adapted to other situations of low added-value products where it is needed to increase the productivity and competitiveness of the product. The system developed uses mechanical and pneumatic solutions which, combined, can be used to solve the identified problem, occupying a restricted space and requiring a small budget. This solution can be translated into guidelines that will allow the analysis of situations where the same system can be applied., The authors would like to thank Mario Cardoso from FicoCables, Lda. for his strong support. The ALGORITMI author would like to acknowledge FCT-Fundacao para a Ciencia e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020.

In several studies about ball-cratering test, a gap remains: how the ball surface texture influences the dynamic of the particles through the contact? In this paper, the influence of ball surface texture in the dragging of abrasive particles on micro-abrasion tests was studied, and the resulting wear mechanisms have been analyzed. The tests were conducted using TiN coated samples and AISI 52100 steel balls provided with different etching times (20 s, 40 s, and 60 s), which induced different balls' texture and roughness. Normal loads of 0.2 N and 0.5 N have been used, utilizing the same rotational speed. Tree different sizes of diamond particles were used: 1–2 μm, 2–4 μm and 4–6 μm. After testing, the coated samples were analyzed by SEM. The steel ball provided with longer etching time caused a slightly higher abrasive damage on the coated samples, and the balls present some embedded particles on the surface, although less than expected. Otherwise, less etched steel ball induced a less intense wear on the samples, enabling light particle sliding/rolling. In this case, the wear rate increased from 4.6 x 10-4 mm3/N·m to 1.3 x 10-3 mm3/N·m when Sa of the balls’ surface raised from 0.047 ± 0.003 μm to 0.239 ± 0.009 μm. The wear mechanisms involved progressed from rolling abrasive mechanism to grooving abrasive mechanism with the growth of the ball surface roughness and abrasive particles size.

O estudo teórico das aplicações da Biomimética nas construções e no desenvolvimento de soluções reúne métodos, conceitos e exemplos de aplicações que podem despertar a criatividade e, ao mesmo tempo, o pensamento crítico a respeito do resgate do equilíbrio entre a ação humana e a natureza. A inspiração da Biomimética pode conscientizar sobre a necessidade de adotarem-se novas tecnologias, padrões e critérios de sobrevivência, considerando o equilíbrio ambiental. Neste sentido, o objetivo deste estudo é descrever a utilização da Biomimética como agente promissor de ideias sustentáveis às problemáticas identificadas na área de ambiência na produção animal. Com uma análise sistemática da literatura, são apresentadas propostas de soluções já utilizadas/projetadas para resolver problemas existentes, por meio de analogias com sistemas naturais. Desta forma, são apontadas tecnologias menos difundidas ou em fase de pesquisa, como construções rápidas e portáteis, estruturas que favoreçam a melhoria do conforto térmico e acústico, tratamento da água e esgoto, e consumo de energia renovável. Todas estas tecnologias são promissoras no processo de otimização de estruturas para a produção animal.

The automotive industry is a pioneer in solutions that meet market expectations. However, in the automotive industry, some less environmentally friendly technologies are still used, such as electroplating. Due to legislative restrictions in several countries, thin coatings made in a vacuum have been replacing coatings traditionally made by electroplating, mainly in decorative terms. This work is more focused on the use of these coatings made in vacuum for optical applications, namely on headlights and exterior backlit components. Although these components are protected during the period of use, there may be situations of contact during the assembly of the components or their repair, necessary to safeguard and to ensure that these coatings have the scratch and wear resistance needed to withstand any treatment deficiency during the operations referred to above. Therefore, this work is essentially focused on the study of the wear resistance of Cr coatings made by PVD (Physical Vapour Deposition) on polymeric substrates. To this end, the coatings previously studied have now been subjected to micro-abrasion tests, with a view to assessing their wear resistance. For this purpose, alumina abrasive has been used, and the wear mechanisms observed in the coatings were studied. The abrasion and scratch tests showed that the most stable film has the one provided with 10-layers, showing greater wear resistance as well, greater adhesion to the substrate and less cohesive failures in the performed tests. Given the nature of the substrate and the coating, the results obtained are very promising, showing that these 10-layer Cr thin coatings can overcome any careless operation during manufacturing, assembly and repair processes, when applied in lightning or backlit components in motor vehicles.

RESUMEN Los pollos de engorde durante la primera fase deben estar protegidos del estrés por frio, especialmente en el inverno, noches y madrugadas frías. Para proteger a los animales, los avicultores han utilizado diferentes estrategias, entre ellas está el uso de varias capas de cortinas para aumentar el nivel de aislamiento térmico y disminuir las pérdidas de calor, disminuyendo también la permeabilidad con el aire externo. En este contexto, es importante dar especial atención a la calidad del aire interno de los galpones avícolas como parte de una producción bajo parámetros de bienestar animal. El presente estudio fue realizado en el municipio de Barbacena, MG, en Brasil, y tuvo como objetivo evaluar la calidad del aire al nivel de los pollos y los trabajadores, específicamente de las concentraciones de amoniaco, dióxido de carbono y monóxido de carbono, en un galpón avícola naturalmente ventilado durante la primera fase de vida de pollos de engorde en el período de inverno, y la influencia del nivel de aislamiento con cortinas laterales sobre las concentraciones de amoniaco. Durante la primera semana experimental, los niveles de amoniaco sobrepasaron los valores aceptables, y se encontró diferencia estadística entre las concentraciones de amoniaco para los diferentes niveles de aislamiento con cortinas laterales. ABSTRACT Broilers during the first phase should be protected from cold stress, especially in the winter, cold nights and early mornings. To protect animals, poultry producers have used different strategies, including the use of multilayer of curtain, to increase the thermal insulation and reduce heat losses, also decreasing the permeability to the external air. In this context it is important to give special attention to the indoor air quality of poultry sheds as part of a production under animal welfare parameters. This study was conducted in the municipality of Barbacena, MG, in Brazil, and aimed to assess air quality at the level of the chickens and workers, specifically concentrations of ammonia, carbon dioxide and carbon monoxide, in a poultry house naturally ventilated during the first phase of life of broilers in the winter period, and the influence of insulation level with side curtains on concentrations of ammonia. During the first experimental week, ammonia levels exceed acceptable values, and statistical difference was found between the concentrations of ammonia for different insulation levels with side curtains.

The objective of this study was to evaluate the efficiency of the Saraz method in order to quantify ammonia emissions generated in opened or hybrid animal production facilities, and to determine an equation for the adjustment method. To do this, we developed beacon equipment, with input and output gas sectors, hoods and absorbent porous material. After the collection, the amount of ammonia captured in the environment was determined in the laboratory. Different ammonia concentrations were evaluated in addition to the different speeds of the exhaust air. Considering the results, it can be concluded that for the situations analyzed the Saraz method is efficient, but as with other methods, with an increase of air velocity and concentration, its efficiency decreases. An equation for the adjustment of the Saraz method was generated to determine the concentration and the rate of ammonia emissions inside animal facilities.