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Project Goal: Development of intelligent coatings for different types of mechanical tools
Current Stage: On-going
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.
Vitor F. C. Sousa; João Castanheira; Francisco J. G. Silva; José S. Fecheira; Gustavo Pinto; Andresa Baptista. Wear Behavior of Uncoated and Coated Tools in Milling Operations of AMPCO (Cu-Be) Alloy. Applied Sciences 2021, 11, 7762 .
AMA StyleVitor F. C. Sousa, João Castanheira, Francisco J. G. Silva, José S. Fecheira, Gustavo Pinto, Andresa Baptista. Wear Behavior of Uncoated and Coated Tools in Milling Operations of AMPCO (Cu-Be) Alloy. Applied Sciences. 2021; 11 (16):7762.
Chicago/Turabian StyleVitor F. C. Sousa; João Castanheira; Francisco J. G. Silva; José S. Fecheira; Gustavo Pinto; Andresa Baptista. 2021. "Wear Behavior of Uncoated and Coated Tools in Milling Operations of AMPCO (Cu-Be) Alloy." Applied Sciences 11, no. 16: 7762.
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.
F. Silva; M. Soares; L. Ferreira; A. Alves; M. Brito; R. Campilho; V. Sousa. A Novel Automated System for the Handling of Car Seat Wires on Plastic Over-Injection Molding Machines. Machines 2021, 9, 141 .
AMA StyleF. Silva, M. Soares, L. Ferreira, A. Alves, M. Brito, R. Campilho, V. Sousa. A Novel Automated System for the Handling of Car Seat Wires on Plastic Over-Injection Molding Machines. Machines. 2021; 9 (8):141.
Chicago/Turabian StyleF. Silva; M. Soares; L. Ferreira; A. Alves; M. Brito; R. Campilho; V. Sousa. 2021. "A Novel Automated System for the Handling of Car Seat Wires on Plastic Over-Injection Molding Machines." Machines 9, no. 8: 141.
The purpose of the present study consists in the development of a conceptual model to optimize assignments between staff’s and workstations with manual assembly processes. This model is planned to satisfy customers’ needs without compromising workers’ health. The development of occupational risk measurement tools is urgent and essential to prevent health problems in work teams. Staff managers should establish appropriate assignments to the characteristics of available and existing resources to complete the tasks without compromising productivity, safety, and health. A life free of work-related musculoskeletal disorders can extend career length and the number of active workers. Therefore, industrial managers need to integrate knowledge from different scientific fields into their decision-making process. They need to identify, specify and focus their efforts on the changes that characterize their productive systems (e.g., layout, workload, cycle time, occupational diseases), and follow the evolution of demographic changes, in order to adjust, with greater celerity, their actions to different dynamic problems. Hence, the implementation of an instrument of measure can contribute to increasing the wellbeing of people at industrial workplaces. Consequently, workers’ health is less compromised over the span of an entire professional career.
Arminda Pata; José Carlos Sá; Francisco José Gomes da Silva; Olga Silva; Luís Barreto; Luís Pinto Ferreira. Conceptual Model of Production Engineers’ Actions to Monitor Workers’ Exposure to Occupational Risks. Recent Advances in Computational Mechanics and Simulations 2021, 79 -87.
AMA StyleArminda Pata, José Carlos Sá, Francisco José Gomes da Silva, Olga Silva, Luís Barreto, Luís Pinto Ferreira. Conceptual Model of Production Engineers’ Actions to Monitor Workers’ Exposure to Occupational Risks. Recent Advances in Computational Mechanics and Simulations. 2021; ():79-87.
Chicago/Turabian StyleArminda Pata; José Carlos Sá; Francisco José Gomes da Silva; Olga Silva; Luís Barreto; Luís Pinto Ferreira. 2021. "Conceptual Model of Production Engineers’ Actions to Monitor Workers’ Exposure to Occupational Risks." Recent Advances in Computational Mechanics and Simulations , no. : 79-87.
The manual assembly processes and the dynamic industrial environment usually requires fast adjustments between work teams and workstations to accomplish customers’ needs. Sometimes, activities are scheduled without considering occupational health of work teams. Those occurrences can compromise work conditions and employee’s health. Thus, the specific objective of this study was to develop a mathematical programming model, to permit monitoring the exposure to occupational risks of workers teams. The mathematical model proposed was validated through solutions generated via the CPLEX® optimization software and OPL language, which was applied in an assembly line of bicycle handlebar where 6 employees produce 800 units per day. First, the results for the original scenario were generated considering the people all the time in the same workstation. The solution was achieved in 12 ms and provided as solution OF = 26153. Then, to allow a deeper perception about the importance of monitoring people exposure at the shop floor, limits of subjection were established. The assignments between work teams and workstations were generated considering those limits. An admissible solution OF = 17888 with the potential to ensure the same output of bicycle handlebar was found in 14 ms. It is expected that the balanced employees’ exposure to the work conditions may contribute to minimize occupational diseases, increase the active aging and ensure future healthy generations, in different manual assembly processes.
Arminda Pata; José Carlos Sá; Gilberto Santos; Francisco José Gomes da Silva; Luís Pinto Ferreira; Luís Barreto. Mathematical Model to Monitory Exposure of People to Occupational Risk in Manual Assembly Processes. Recent Advances in Computational Mechanics and Simulations 2021, 122 -134.
AMA StyleArminda Pata, José Carlos Sá, Gilberto Santos, Francisco José Gomes da Silva, Luís Pinto Ferreira, Luís Barreto. Mathematical Model to Monitory Exposure of People to Occupational Risk in Manual Assembly Processes. Recent Advances in Computational Mechanics and Simulations. 2021; ():122-134.
Chicago/Turabian StyleArminda Pata; José Carlos Sá; Gilberto Santos; Francisco José Gomes da Silva; Luís Pinto Ferreira; Luís Barreto. 2021. "Mathematical Model to Monitory Exposure of People to Occupational Risk in Manual Assembly Processes." Recent Advances in Computational Mechanics and Simulations , no. : 122-134.
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.
Andresa Baptista; Gustavo Pinto; Francisco Silva; Andreia Ferreira; Arnaldo Pinto; Vitor Sousa. Wear Characterization of Chromium PVD Coatings on Polymeric Substrate for Automotive Optical Components. Coatings 2021, 11, 555 .
AMA StyleAndresa Baptista, Gustavo Pinto, Francisco Silva, Andreia Ferreira, Arnaldo Pinto, Vitor Sousa. Wear Characterization of Chromium PVD Coatings on Polymeric Substrate for Automotive Optical Components. Coatings. 2021; 11 (5):555.
Chicago/Turabian StyleAndresa Baptista; Gustavo Pinto; Francisco Silva; Andreia Ferreira; Arnaldo Pinto; Vitor Sousa. 2021. "Wear Characterization of Chromium PVD Coatings on Polymeric Substrate for Automotive Optical Components." Coatings 11, no. 5: 555.
Though new manufacturing processes that revolutionize the landscape regarding the rapid manufacture of parts have recently emerged, the machining process remains alive and up-to-date in this context, always presenting itself as a manufacturing process with several variants and allowing for high dimensional accuracy and high levels of surface finish
Francisco Silva. Metal Machining—Recent Advances, Applications, and Challenges. Metals 2021, 11, 580 .
AMA StyleFrancisco Silva. Metal Machining—Recent Advances, Applications, and Challenges. Metals. 2021; 11 (4):580.
Chicago/Turabian StyleFrancisco Silva. 2021. "Metal Machining—Recent Advances, Applications, and Challenges." Metals 11, no. 4: 580.
Purpose: This study was carried out in a cork company and its purpose was to observe and analyze the practices and methods used during the tools/series change moments and to propose improvements and alternatives to these same procedures so that the time needed to carry out the setup is reduced by 15% in both lines. Methodology/Approach:The methodology included the following phases: 1st - historical data collection and setup video recording, 2nd - footage analysis and conduction of informal interviews with employees, 3rd - flow, Gantt, and spaghetti charts creation and making of an action plan based on the waste and improvement opportunities identified in video analysis, 4th - validation with the line workers of the new operating mode created with the Single Minute Exchange of Dies (SMED) tool and communication to the Maintenance department about their role in this project, 5th - making and placement of plasticized cards on the cutting lines to ensure that new operating mode is followed and carrying out the actions identified in the action plan. Findings: Throughout this project using observations, video recording and its subsequent analysis, as well as interviews to the workers operating in the line, it was found the existence of several actions carried out by them during the setups which did not add value to the product, lack of adequate tools for the work to be performed and lack of work tools in general Research Limitation/implication: The study was limited by the lines and products under study and by the duration of the curricular internship, which was about five months. Originality/Value of paper: The article demonstrates the added value in terms of product quality and production output rate that SMED methodology can bring to companies that adopt the lean philosophy and in particular this continuous improvement tool.
Alexandre Silva; José C. Sá; Gilberto Santos; Francisco J.G. Silva; Luís P. Ferreira; Maria T. Pereira. A Comparison of the Application of the SMED Methodology in Two Different Cutting Lines. Quality Innovation Prosperity 2021, 25, 124 -149.
AMA StyleAlexandre Silva, José C. Sá, Gilberto Santos, Francisco J.G. Silva, Luís P. Ferreira, Maria T. Pereira. A Comparison of the Application of the SMED Methodology in Two Different Cutting Lines. Quality Innovation Prosperity. 2021; 25 (1):124-149.
Chicago/Turabian StyleAlexandre Silva; José C. Sá; Gilberto Santos; Francisco J.G. Silva; Luís P. Ferreira; Maria T. Pereira. 2021. "A Comparison of the Application of the SMED Methodology in Two Different Cutting Lines." Quality Innovation Prosperity 25, no. 1: 124-149.
Tires are a highly relevant component in the industry of global mobility. Also, in the automotive industry, they play a key role. They are a composite structure formed by multiple layers of different materials such as rubber compounds, steel wires and polyamide cords. Between the tire tread and steel belts, a cap ply layer is used to restrict the tire’s expansion due to centrifugal forces. The cap ply is manufactured by a process where polyamide cords are impregnated with a rubber compound, which is extruded. When the extrusion phase of the rubber compound is poorly controlled, the cap ply belts show premature vulcanization or lack of impregnation signs. These defects compromise the overall quality of the tire, as well as its safety features to its user. To improve the production process of cap ply, a CFD (Computational Fluid Dynamics) analysis was performed to study the flow of the rubber compound inside the extruder head by using two different temperature controls. The vulcanization and rheological properties of the rubber compound were studied to support numerical analysis data. Through thermographic imaging and data collection with a portable device (Arduino UNO) connected to sensors and modules, experimental data related to the temperature distribution was analyzed together with the numerical analysis. By critically analyzing all the data obtained, a new temperature control was created, which proved to be extremely efficient, reducing the amount of scrap and electric energy consumed.
André Silva; Francisco J.G. Silva; Raul D.S.G. Campilho; Pedro M.P.F. Neves. A new approach to temperature control in the extrusion process of composite tire products. Journal of Manufacturing Processes 2021, 65, 80 -96.
AMA StyleAndré Silva, Francisco J.G. Silva, Raul D.S.G. Campilho, Pedro M.P.F. Neves. A new approach to temperature control in the extrusion process of composite tire products. Journal of Manufacturing Processes. 2021; 65 ():80-96.
Chicago/Turabian StyleAndré Silva; Francisco J.G. Silva; Raul D.S.G. Campilho; Pedro M.P.F. Neves. 2021. "A new approach to temperature control in the extrusion process of composite tire products." Journal of Manufacturing Processes 65, no. : 80-96.
Grade P91 is a relatively new class of steel, which has received special attention from designers because it presents extremely interesting characteristics for specific applications. This steel exhibits ideal properties for demanding applications, especially involving high temperature and pressure, being employed in facilities such as power plants and other equipment, such as heat exchangers. P91 welds usually need heat treatments, which are already parameterized in the codes. However, standardized treatments are time-consuming and harmful to the environment, as they massively consume energy. Some attempts have been made in the past to reduce the time and energy spent on these treatments. This work aims to extend this study, now presenting better solutions than those obtained previously. This work presents four new conditions for the heat treatment of joints carried out on P91 steel, with a view to reducing processing time, reducing energy consumption, and an even better balance between mechanical strength and elongation after failure. Heat treatment conditions were established in which there was a loss of about 14% in Ultimate Tensile Strength (UTS), but in which a gain of about 50% in elongation was obtained, compared to welding without any treatment, but also with 10% losses in the UTS and 30% gains in elongation when compared to the solution recommended as more correct in the codes, saving a lot of time and energy in the treatment process. Thus, these solutions may be adopted in the future with gains in terms of productivity and economic and environmental sustainability.
Vitor Sousa; Francisco Silva; António Pinho; António Pereira; Olga Paiva. Enhancing Heat Treatment Conditions of Joints in Grade P91 Steel: Looking for More Sustainable Solutions. Metals 2021, 11, 495 .
AMA StyleVitor Sousa, Francisco Silva, António Pinho, António Pereira, Olga Paiva. Enhancing Heat Treatment Conditions of Joints in Grade P91 Steel: Looking for More Sustainable Solutions. Metals. 2021; 11 (3):495.
Chicago/Turabian StyleVitor Sousa; Francisco Silva; António Pinho; António Pereira; Olga Paiva. 2021. "Enhancing Heat Treatment Conditions of Joints in Grade P91 Steel: Looking for More Sustainable Solutions." Metals 11, no. 3: 495.
To remain competitive, companies must continuously improve the processes at hand, be they administrative, production, or logistics. The objective of the study described in this paper was to develop a decision-making tool based on a simulation model to support the production of knits and damask fabrics. The tool was used to test different control strategies for material flow, from the raw material warehouse to the finished product warehouse, and thus can also be used to evaluate the impacts of these strategies on the productivity. The data upon which the decision support tool was built were collected from five sectors of the plant: the raw material warehouse, knit production, damask production, finishing work, and the finished product warehouse. The decision support tool met the objectives of the project, with all five strategies developed showing positive results. Knit and damask production rates increased by up to 8% and 44%, respectively, and a reduction of 75% was observed in the waiting time on the point of entry to the finishing work area, compared to the company’s existing system.
Vítor Silva; Luís Ferreira; Francisco Silva; Benny Tjahjono; Paulo Ávila. Simulation-Based Decision Support System to Improve Material Flow of a Textile Company. Sustainability 2021, 13, 2947 .
AMA StyleVítor Silva, Luís Ferreira, Francisco Silva, Benny Tjahjono, Paulo Ávila. Simulation-Based Decision Support System to Improve Material Flow of a Textile Company. Sustainability. 2021; 13 (5):2947.
Chicago/Turabian StyleVítor Silva; Luís Ferreira; Francisco Silva; Benny Tjahjono; Paulo Ávila. 2021. "Simulation-Based Decision Support System to Improve Material Flow of a Textile Company." Sustainability 13, no. 5: 2947.
Additive manufacturing (AM) is a unique manufacturing process that disrupted completely the way which components are made, since this process is capable of producing complex parts layer after layer. As a matter of fact, one of its distinct technologies is metal laser beam powder bed fusion (mLB-PBF), also known as selective laser melting (SLM) or direct metal laser sintering (DMLS), which creates metallic parts with the aid of a high-energy laser beam. One of the most employed superalloys in this technology is the Inconel 718 (IN718), a precipitation-hardened alloy that is used in the marine, nuclear power plants, gas turbines, and aerospace field due to its capacity of retaining good mechanical properties at high temperatures. The research novelty of this review manuscript is the compilation of all kinds of information from the last 15 years of investigation about IN718 parts produced via mLB-PBF, namely, information related to distinct heat treatments and the influence they have in increasing mechanical properties of the manufactured components, as well as reducing residual stresses (RS) and part porosity. Throughout the review, it can be seen that the expected microstructure in the as-built state is characterized by fine columnar grains and a saturated γ matrix with the presence of the Laves phase and carbides. However, distinct heat treatments can be employed which lead to the dissolution of the undesired phases (Laves and carbides), the precipitation of the strengthening phases (γ’ and γ”), and the porosity decrease. Furthermore, it was also shown that heat treatments as well as optimized process parameters can be held accountable for lowering the RS of the IN718 manufactured parts. Nevertheless, there are still some problems to overcome, namely, the mechanical properties variability when subjecting IN718 powder to different process parameters. Moreover, the RS evolution under different heat treatments needs to be further investigated.
Óscar Teixeira; Francisco J. G. Silva; Eleonora Atzeni. Residual stresses and heat treatments of Inconel 718 parts manufactured via metal laser beam powder bed fusion: an overview. The International Journal of Advanced Manufacturing Technology 2021, 113, 3139 -3162.
AMA StyleÓscar Teixeira, Francisco J. G. Silva, Eleonora Atzeni. Residual stresses and heat treatments of Inconel 718 parts manufactured via metal laser beam powder bed fusion: an overview. The International Journal of Advanced Manufacturing Technology. 2021; 113 (11-12):3139-3162.
Chicago/Turabian StyleÓscar Teixeira; Francisco J. G. Silva; Eleonora Atzeni. 2021. "Residual stresses and heat treatments of Inconel 718 parts manufactured via metal laser beam powder bed fusion: an overview." The International Journal of Advanced Manufacturing Technology 113, no. 11-12: 3139-3162.
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.
A. Baptista; F.J.G. Silva; G. Pinto; J. Porteiro; J. Míguez; R. Alexandre; V.F.C. Sousa. Influence of the ball surface texture in the dragging of abrasive particles on micro-abrasion wear tests. Wear 2021, 203730 .
AMA StyleA. Baptista, F.J.G. Silva, G. Pinto, J. Porteiro, J. Míguez, R. Alexandre, V.F.C. Sousa. Influence of the ball surface texture in the dragging of abrasive particles on micro-abrasion wear tests. Wear. 2021; ():203730.
Chicago/Turabian StyleA. Baptista; F.J.G. Silva; G. Pinto; J. Porteiro; J. Míguez; R. Alexandre; V.F.C. Sousa. 2021. "Influence of the ball surface texture in the dragging of abrasive particles on micro-abrasion wear tests." Wear , no. : 203730.
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.
Andreia A. Ferreira; Francisco J. G. Silva; Arnaldo G. Pinto; Vitor F. C. Sousa. Characterization of Thin Chromium Coatings Produced by PVD Sputtering for Optical Applications. Coatings 2021, 11, 215 .
AMA StyleAndreia A. Ferreira, Francisco J. G. Silva, Arnaldo G. Pinto, Vitor F. C. Sousa. Characterization of Thin Chromium Coatings Produced by PVD Sputtering for Optical Applications. Coatings. 2021; 11 (2):215.
Chicago/Turabian StyleAndreia A. Ferreira; Francisco J. G. Silva; Arnaldo G. Pinto; Vitor F. C. Sousa. 2021. "Characterization of Thin Chromium Coatings Produced by PVD Sputtering for Optical Applications." Coatings 11, no. 2: 215.
Coatings usually play an important role in terms of machining tool behaviour and lifespan. TiAlN is a well-known PVD coating but, the permanent need for improved performance is inducing new compositions around this coating. In this work, the wear behaviour of different PVD coated tools with different geometries was analysed, in the milling of pre-hardened tool steel. The selected tools had two different geometries, namely ball nose end mill and end mill tools. Additionally, these were coated with two different PVD coatings, TiAlSiN and TiAlN. These tools were employed in milling operations of W 1.2711 pre-hardened tool steel. The cutting parameters were defined in a way to enable a valid comparison between the milling tools, varying only feed and cutting length, to analyse the influence of these parameters on the tool's wear mechanisms. Cutting force data was collected during the milling tests using a dynamometer in order to identify the different wear stages of the tool, and surface roughness was measured after each test. Furthermore, after the milling tests the tools were submitted to a SEM analysis, in order to analyse the wear mechanisms of each coated tool. The main wear mechanisms that were identified in both coatings are adhesion and abrasion, followed by coating delamination. Moreover, the analysed wear was less significant in the TiAlSiN PVD coated tools used, mainly in the ball-nose tools, providing as well very good surface roughness of the machined surface. The surface morphology of the tool and the direction of the grooves left on the tool surface after grinding operations of the uncoated tool showed a significant influence on the coating wear mode. The best machining conditions have been established, taking into account the lowest surface roughness obtained on the machined surface and the lowest wear rate of the tool.
Vitor F.C. Sousa; F.J.G. Silva; R. Alexandre; J.S. Fecheira. Study of the wear behaviour of TiAlSiN and TiAlN PVD coated tools on milling operations of pre-hardened tool steel. Wear 2021, 476, 203695 .
AMA StyleVitor F.C. Sousa, F.J.G. Silva, R. Alexandre, J.S. Fecheira. Study of the wear behaviour of TiAlSiN and TiAlN PVD coated tools on milling operations of pre-hardened tool steel. Wear. 2021; 476 ():203695.
Chicago/Turabian StyleVitor F.C. Sousa; F.J.G. Silva; R. Alexandre; J.S. Fecheira. 2021. "Study of the wear behaviour of TiAlSiN and TiAlN PVD coated tools on milling operations of pre-hardened tool steel." Wear 476, no. : 203695.
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.
Vitor Sousa; Francisco Da Silva; Gustavo Pinto; Andresa Baptista; Ricardo Alexandre. Characteristics and Wear Mechanisms of TiAlN-Based Coatings for Machining Applications: A Comprehensive Review. Metals 2021, 11, 260 .
AMA StyleVitor Sousa, Francisco Da Silva, Gustavo Pinto, Andresa Baptista, Ricardo Alexandre. Characteristics and Wear Mechanisms of TiAlN-Based Coatings for Machining Applications: A Comprehensive Review. Metals. 2021; 11 (2):260.
Chicago/Turabian StyleVitor Sousa; Francisco Da Silva; Gustavo Pinto; Andresa Baptista; Ricardo Alexandre. 2021. "Characteristics and Wear Mechanisms of TiAlN-Based Coatings for Machining Applications: A Comprehensive Review." Metals 11, no. 2: 260.
Micro-abrasion remains a test configuration hugely used, mainly for thin coatings. Several studies have been carried out investigating the parameters around this configuration. Recently, a new study was launched studying the behavior of different ball materials in abrasive particles’ dynamics in the contact area. This study intends to extend that study, investigating new ball materials never used so far in this test configuration. Thus, commercial balls of American Iron and Steel Institute (AISI) 52100 steel, Stainless Steel (SS) (AISI) 304 steel and Polytetrafluoroethylene (PTFE) were used under different test conditions and abrasive particles, using always the same coating for reference. Craters generated on the coated samples’ surface and tracks on the balls’ surface were carefully observed by Scanning Electron Microscopy (SEM) and 3D microscopy in order to understand the abrasive particles’ dynamics. As a softer material, more abrasive particles were entrapped on the PTFE ball’s surface, generating grooving wear on the samples. SS AISI 304 balls, being softer than the abrasive particles (diamond), also allowed particle entrapment, originating from grooving wear. AISI 52100 steel balls presented particle dynamics that are already known. Thus, this study extends the knowledge already existing, allowing to better select the ball material to be used in ball-cratering tests.
Gustavo Pinto; Andresa Baptista; Francisco Silva; Jacobo Porteiro; José Míguez; Ricardo Alexandre. Study on the Influence of the Ball Material on Abrasive Particles’ Dynamics in Ball-Cratering Thin Coatings Wear Tests. Materials 2021, 14, 668 .
AMA StyleGustavo Pinto, Andresa Baptista, Francisco Silva, Jacobo Porteiro, José Míguez, Ricardo Alexandre. Study on the Influence of the Ball Material on Abrasive Particles’ Dynamics in Ball-Cratering Thin Coatings Wear Tests. Materials. 2021; 14 (3):668.
Chicago/Turabian StyleGustavo Pinto; Andresa Baptista; Francisco Silva; Jacobo Porteiro; José Míguez; Ricardo Alexandre. 2021. "Study on the Influence of the Ball Material on Abrasive Particles’ Dynamics in Ball-Cratering Thin Coatings Wear Tests." Materials 14, no. 3: 668.
The main purpose of this paper was to introduce procedural changes based on a type of human resources management tool using Lean Leadership (LL). We sought to determine which Lean Tools (LTs) are able to promote a rapid impact on a company; namely, we aimed to determine which LTs are able to facilitate fast and positive results for companies after their implementation, thus allowing for quick wins. This study was conducted at a medium-sized Portuguese company in the metalworking sector. Results were assessed from two surveys (involving 17 people) regarding perceptions of employee awareness in the machining area for Quality, Maintenance/Equipment, Process/Products, Leadership/Management by Objectives, and Trust and Training. The surveys were conducted at the beginning of the study and at the end of a quarterly period. LTs were used over a period of three months, thus enabling changes to the company’s manufacturing processes which could lead to improved organization, orientation, consistency and viability. Three months were considered an adequate time period to measure whether the tools were effective in the production of quick wins or not. LL allowed for greater awareness of the importance of LTs, the most important feature of which is the aggregation of all of the employees’ energies, which culminates in better operational efficiency and an increase in the employees’ overall positive perceptions of their company’s principles and mindset. The introduction of LL, as well as the implementation of 10 LTs, which are considered to be Quick-Win Tools, enabled employees to improve their perceptions of their company by 6.1%. Lean tools can be implemented quickly and are easily understood by their intended users. These benefits provide additional motivation for their use and for the achievement of highly satisfactory operating results across production areas. This study aims to identify which lean tools allow companies to obtain benefits/gains quickly. This outcome is the main contribution of this study to the scientific community and to companies. A Quick Win means a rapid improvement in a short period of time. As such, lean tools that provide Quick Wins also contribute to economic development. Due to the restricted time period imposed by the main purpose of this study, statistical analysis of the results was unfeasible.
Jorge Rodrigues; José Carlos Sá; Francisco J. G. Silva; Luís Pinto Ferreira; Genett Jimenez; Gilberto Santos. A Rapid Improvement Process through “Quick-Win” Lean Tools: A Case Study. Systems 2020, 8, 55 .
AMA StyleJorge Rodrigues, José Carlos Sá, Francisco J. G. Silva, Luís Pinto Ferreira, Genett Jimenez, Gilberto Santos. A Rapid Improvement Process through “Quick-Win” Lean Tools: A Case Study. Systems. 2020; 8 (4):55.
Chicago/Turabian StyleJorge Rodrigues; José Carlos Sá; Francisco J. G. Silva; Luís Pinto Ferreira; Genett Jimenez; Gilberto Santos. 2020. "A Rapid Improvement Process through “Quick-Win” Lean Tools: A Case Study." Systems 8, no. 4: 55.
This project was carried out at a company in the electric mobility sector, which manufactures chargers for electric vehicles, specifically in the wiring section. The main objective of the developed work was to improve the production processes in order to enhance responsiveness to the growing demand. After analyzing the processes in the section, the objectives were outlined to enable the improvement of some practices in the production department, such as the ones related to the organization of the raw material supermarket, as well as the calculation of the wiring consumption by chargers, and the implementation of a production control system. After the improvement actions were implemented, it was possible to observe a 14,9% reduction in the changeover process of the cable cutting process; weekly wiring consumptions were estimated, and procedures were defined to generate orders of raw material and supply to the workstation, which led to the elimination of stock shortages. In addition, worker autonomy increased and production downtime was reduced.
R. Pena; L.P. Ferreira; F.J.G. Silva; J.C. Sá; N.O. Fernandes; T. Pereira. Lean manufacturing applied to a wiring production process. Procedia Manufacturing 2020, 51, 1387 -1394.
AMA StyleR. Pena, L.P. Ferreira, F.J.G. Silva, J.C. Sá, N.O. Fernandes, T. Pereira. Lean manufacturing applied to a wiring production process. Procedia Manufacturing. 2020; 51 ():1387-1394.
Chicago/Turabian StyleR. Pena; L.P. Ferreira; F.J.G. Silva; J.C. Sá; N.O. Fernandes; T. Pereira. 2020. "Lean manufacturing applied to a wiring production process." Procedia Manufacturing 51, no. : 1387-1394.
The products related to automotive industry need to be extremely competitive. The metallic wire ropes used to open doors in the vehicles are based on a braided wire rope provided with accessories. The more expensive is the vehicle, the more complex is the required final wire rope. In order to prevent the corrosion and reduce noise, the internal metallic cable can be coated with a polymer via extrusion. However, this coating needs to be removed from the extremities of the metallic cable, allowing the zamak injection of the mechanical terminals, preventing die casting defects. Nevertheless, the standard machines able to produce the mechanical terminals by die casting process were always prepared to work only with non-coated metallic cable. Customers demanding coated metallic cables impose the need to adapt the standard machines to this new reality. Thus, new systems needed to be added to the standard machine, allowing the metallic cable strip operation. Moreover, this operation needs to be added to the process but without repercussions on the cycle time. Different approaches were studied and tested in order to find the best solution. The new device was designed and produced, allowing its test in real conditions. The system based on just one blade did not show satisfactory results, being necessary the use of a system based on multiple blades. The new device, when connected to the standard machine, allows to produce wire ropes up to 2.5 meters long, striped in both sides, letting the die casting injection of the zamak terminal in one extremity, with a cycle time of 7 seconds (1000 wire ropes per hour, as they are produced in couples).
D. Figueiredo; F.J.G. Silva; R.D.S.G. Campilho; A. Silva; C. Pimentel; J.C.O. Matias. A new concept of automated manufacturing process for wire rope terminals. Procedia Manufacturing 2020, 51, 431 -437.
AMA StyleD. Figueiredo, F.J.G. Silva, R.D.S.G. Campilho, A. Silva, C. Pimentel, J.C.O. Matias. A new concept of automated manufacturing process for wire rope terminals. Procedia Manufacturing. 2020; 51 ():431-437.
Chicago/Turabian StyleD. Figueiredo; F.J.G. Silva; R.D.S.G. Campilho; A. Silva; C. Pimentel; J.C.O. Matias. 2020. "A new concept of automated manufacturing process for wire rope terminals." Procedia Manufacturing 51, no. : 431-437.