The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
Gilmar Guimaraes - One of the best experts on this subject based on the ideXlab platform.
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temperature determination at the chip Tool Interface using an inverse thermal model considering the Tool and Tool holder
Journal of Materials Processing Technology, 2006Co-Authors: S R Carvalho, S Lima M M E Silva, Alisson Rocha Machado, Gilmar GuimaraesAbstract:Abstract The temperature fields generated in the cutting processes are subject of extensive research. The studies of these thermal fields in machining are very important for the development of new technologies aiming to increase the Tool lives and to reduce production costs. Since the direct temperature measurements at the chip–Tool Interface are very complex this work proposes the estimation of the temperature and the heat flux at the chip–Tool Interface using the inverse heat conduction problem technique. The thermal model is obtained by a numerical solution of the transient three-dimensional heat diffusion equation that considers both the Tool and the Tool holder assembly. To determine the solution equation the finite volume method is used. Changing in the thermal properties with the temperature and heat losses by convection are also considered. Several cutting tests using cemented carbide Tools were performed in order to check the model and to verify the influence of the cutting parameters on the temperature field.
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Temperature determination at the chip–Tool Interface using an inverse thermal model considering the Tool and Tool holder
Journal of Materials Processing Technology, 2006Co-Authors: S R Carvalho, Alisson Rocha Machado, S.m.m. Lima E Silva, Gilmar GuimaraesAbstract:Abstract The temperature fields generated in the cutting processes are subject of extensive research. The studies of these thermal fields in machining are very important for the development of new technologies aiming to increase the Tool lives and to reduce production costs. Since the direct temperature measurements at the chip–Tool Interface are very complex this work proposes the estimation of the temperature and the heat flux at the chip–Tool Interface using the inverse heat conduction problem technique. The thermal model is obtained by a numerical solution of the transient three-dimensional heat diffusion equation that considers both the Tool and the Tool holder assembly. To determine the solution equation the finite volume method is used. Changing in the thermal properties with the temperature and heat losses by convection are also considered. Several cutting tests using cemented carbide Tools were performed in order to check the model and to verify the influence of the cutting parameters on the temperature field.
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Cooling ability of cutting fluids and measurement of the chip‐Tool Interface temperatures
Industrial Lubrication and Tribology, 2002Co-Authors: Wisley Falco Sales, Alisson Rocha Machado, Gilmar Guimaraes, Emmanuel O. EzugwuAbstract:Many machining researches are focused on cutting Tools mainly due to the wear developed as a result of high temperatures generated that accelerate thermally related wear mechanisms, consequently reducing Tool life. Cutting fluids are used in machining operations to minimize cutting temperature although there is no available indicator of their cooling ability. In this study, a method to determine the cooling ability of cutting fluids is proposed. A thermocouple technique was used to verify the chip‐Tool Interface temperature of various cutting fluids during turning operation. The method consists of measuring the temperature drop from 300°C up to room temperature after heating a standardised AISI 8640 workpiece and fixing it to the chuck of a lathe and with a constant spindle speed of 150 rpm the cutting fluid was applied to a specific point. The temperature was measured and registered by an infrared thermosensor with the aid of an AC/DC data acquisition board and a PC. The convective heat exchange coeffici...
Brahim Bourouga - One of the best experts on this subject based on the ideXlab platform.
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thermal contact resistance estimation influence of the pressure contact and the coating layer during a hot forming process
International Journal of Material Forming, 2012Co-Authors: Bakri Abdulhay, Brahim Bourouga, Christine DessainAbstract:The Thermal Contact Resistance RC Estimation constitutes an encountered problem to be resolved in any forming process. To fairly simulate a part cooling during a hot stamping process, an experimental device was designed and developed by the Laboratoire de Thermocinetique de Nantes—France in collaboration with ArcelorMittal R&D Montataire—France. The object is to estimate the thermal contact resistance at the part/Tool Interface during the three stage of the hot stamping process. During hot stamping phases, different contact types occur at the part/Tool Interface. The forming phase is characterized by a dynamic contact due to the increasing effort applied by the punch. At the contact Interfaces, thermal contact resistances RC are estimated experimentally through a non-linear 1D inverse technique founded on sequential method of Beck. Experiments were carried out on hot stamping samples made of Usibor 1500P® and 22MnB5 galvanized steel. The range of prospected stamping pressure varies from 10 to 30 MPa. The analysis of the effort curves shows the same mechanical resistance law of the part during the forming phase, whatever the consign effort settled to reach the maximum stamping pressure. The RC value estimated for the galvanized steel is 33% lower than the one estimated for Usibor 1500P®. It is due to a higher harmonic thermal conductivity of the coated material. Results have been established as correlation of type: RC = f(P) to be used for numerical simulation.
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Thermal contact resistance estimation: influence of the pressure contact and the coating layer during a hot forming process
International Journal of Material Forming, 2012Co-Authors: Bakri Abdulhay, Brahim Bourouga, Christine DessainAbstract:The Thermal Contact Resistance R _ C Estimation constitutes an encountered problem to be resolved in any forming process. To fairly simulate a part cooling during a hot stamping process, an experimental device was designed and developed by the Laboratoire de Thermocinétique de Nantes—France in collaboration with ArcelorMittal R&D Montataire—France. The object is to estimate the thermal contact resistance at the part/Tool Interface during the three stage of the hot stamping process. During hot stamping phases, different contact types occur at the part/Tool Interface. The forming phase is characterized by a dynamic contact due to the increasing effort applied by the punch. At the contact Interfaces, thermal contact resistances R _ C are estimated experimentally through a non-linear 1D inverse technique founded on sequential method of Beck. Experiments were carried out on hot stamping samples made of Usibor 1500P® and 22MnB5 galvanized steel. The range of prospected stamping pressure varies from 10 to 30 MPa . The analysis of the effort curves shows the same mechanical resistance law of the part during the forming phase, whatever the consign effort settled to reach the maximum stamping pressure. The R _ C value estimated for the galvanized steel is 33% lower than the one estimated for Usibor 1500P®. It is due to a higher harmonic thermal conductivity of the coated material. Results have been established as correlation of type: R _ C = f ( P ) to be used for numerical simulation.
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development of estimation procedure of contact heat transfer coefficient at the part Tool Interface in hot stamping process
Heat Transfer Engineering, 2011Co-Authors: Bakri Abdulhay, Brahim Bourouga, Christine Dessain, Gilles Brun, Joel WilsiusAbstract:Energy efficiency, a high level of passenger safety, and weight reduction of the vehicles still constitute the main functional elements for the design of modern car body structures. Toward this objective, the usage of advanced sheet-metal forming technologies like hot stamping of quenchable boron manganese steel is developing nowadays. Hot stamping is a combination of hot forming and simultaneously quenching and hardening of the blank. In this article, an experimental procedure developed to estimate the thermal conductance at the part–Tool Interface during a hot stamping procedure is presented. The Tools set (punch and die) has been designed to form omega-shaped samples. This work represents the first stage of the procedure development where the standard experiment is a simple compressive load of sample in the bottom of the omega-shape die, considering the real hot-stamping conditions. Tests are carried out under different contact pressure values for two different blank materials (Usibor 1500P and a mater...
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Development of Estimation Procedure of Contact Heat Transfer Coefficient at the Part–Tool Interface in Hot Stamping Process
Heat Transfer Engineering, 2011Co-Authors: Bakri Abdulhay, Brahim Bourouga, Christine Dessain, Brun Gilles, Joel WilsiusAbstract:Energy efficiency, a high level of passenger safety, and weight reduction of the vehicles still constitute the main functional elements for the design of modern car body structures. Toward this objective, the usage of advanced sheet-metal forming technologies like hot stamping of quenchable boron manganese steel is developing nowadays. Hot stamping is a combination of hot forming and simultaneously quenching and hardening of the blank. In this article, an experimental procedure developed to estimate the thermal conductance at the part–Tool Interface during a hot stamping procedure is presented. The Tools set (punch and die) has been designed to form omega-shaped samples. This work represents the first stage of the procedure development where the standard experiment is a simple compressive load of sample in the bottom of the omega-shape die, considering the real hot-stamping conditions. Tests are carried out under different contact pressure values for two different blank materials (Usibor 1500P and a mater...
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Thermal contact resistance estimation at the blank/Tool Interface: experimental approach to simulate the blank cooling during the hot stamping process
International Journal of Material Forming, 2010Co-Authors: Bakri Abdul Hay, Brahim Bourouga, Christine DessainAbstract:In the present paper, an experimental device designed and developed to estimate the thermal contact resistance (R _ C ) at the blank/Tool Interface is presented along with the simulation chain used to validate the experimental results. The designed stamping Tool is composed of a die and a punch made in Z160CDV12 steel and presenting an omega shape. Sample and Tools are thermally instrumented with thermocouples type K sheathed with silky glass, forming heat flux-meters in the most interesting locations in the Tools. Hot stamping tests are carried out under different contact pressure values covering the range from 5 to 30 MPa . Tested blank material is a C-Mn steel, named Usibor 1500P. Temperatures measurement in the Tool and the blank allow the estimation of Rc evolution for every contact pressure. Experiments were carried out in the same conditions of the industrial process. The recorded blank temperature shows systematically a slope change around 400°C; it is linked to the microstructure transformation from austenite to martensite. This metallurgical transformation is also observed on the R _ C evolution curve. Linked to the microstructure transformation, this singularity tends to vanish with increasing pressure. That is due to the increasing of the cooling velocity with the stamping pressure increasing. Results have been established as correlation of type: R _ C = R _ C ( P ) to be used for numerical simulation through Pam-Stamp and Abaqus. Experimental and numerical parameters have been compared and the small temperature difference shows the good quality of results.
Christine Dessain - One of the best experts on this subject based on the ideXlab platform.
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Thermal contact resistance estimation: influence of the pressure contact and the coating layer during a hot forming process
International Journal of Material Forming, 2012Co-Authors: Bakri Abdulhay, Brahim Bourouga, Christine DessainAbstract:The Thermal Contact Resistance R _ C Estimation constitutes an encountered problem to be resolved in any forming process. To fairly simulate a part cooling during a hot stamping process, an experimental device was designed and developed by the Laboratoire de Thermocinétique de Nantes—France in collaboration with ArcelorMittal R&D Montataire—France. The object is to estimate the thermal contact resistance at the part/Tool Interface during the three stage of the hot stamping process. During hot stamping phases, different contact types occur at the part/Tool Interface. The forming phase is characterized by a dynamic contact due to the increasing effort applied by the punch. At the contact Interfaces, thermal contact resistances R _ C are estimated experimentally through a non-linear 1D inverse technique founded on sequential method of Beck. Experiments were carried out on hot stamping samples made of Usibor 1500P® and 22MnB5 galvanized steel. The range of prospected stamping pressure varies from 10 to 30 MPa . The analysis of the effort curves shows the same mechanical resistance law of the part during the forming phase, whatever the consign effort settled to reach the maximum stamping pressure. The R _ C value estimated for the galvanized steel is 33% lower than the one estimated for Usibor 1500P®. It is due to a higher harmonic thermal conductivity of the coated material. Results have been established as correlation of type: R _ C = f ( P ) to be used for numerical simulation.
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thermal contact resistance estimation influence of the pressure contact and the coating layer during a hot forming process
International Journal of Material Forming, 2012Co-Authors: Bakri Abdulhay, Brahim Bourouga, Christine DessainAbstract:The Thermal Contact Resistance RC Estimation constitutes an encountered problem to be resolved in any forming process. To fairly simulate a part cooling during a hot stamping process, an experimental device was designed and developed by the Laboratoire de Thermocinetique de Nantes—France in collaboration with ArcelorMittal R&D Montataire—France. The object is to estimate the thermal contact resistance at the part/Tool Interface during the three stage of the hot stamping process. During hot stamping phases, different contact types occur at the part/Tool Interface. The forming phase is characterized by a dynamic contact due to the increasing effort applied by the punch. At the contact Interfaces, thermal contact resistances RC are estimated experimentally through a non-linear 1D inverse technique founded on sequential method of Beck. Experiments were carried out on hot stamping samples made of Usibor 1500P® and 22MnB5 galvanized steel. The range of prospected stamping pressure varies from 10 to 30 MPa. The analysis of the effort curves shows the same mechanical resistance law of the part during the forming phase, whatever the consign effort settled to reach the maximum stamping pressure. The RC value estimated for the galvanized steel is 33% lower than the one estimated for Usibor 1500P®. It is due to a higher harmonic thermal conductivity of the coated material. Results have been established as correlation of type: RC = f(P) to be used for numerical simulation.
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development of estimation procedure of contact heat transfer coefficient at the part Tool Interface in hot stamping process
Heat Transfer Engineering, 2011Co-Authors: Bakri Abdulhay, Brahim Bourouga, Christine Dessain, Gilles Brun, Joel WilsiusAbstract:Energy efficiency, a high level of passenger safety, and weight reduction of the vehicles still constitute the main functional elements for the design of modern car body structures. Toward this objective, the usage of advanced sheet-metal forming technologies like hot stamping of quenchable boron manganese steel is developing nowadays. Hot stamping is a combination of hot forming and simultaneously quenching and hardening of the blank. In this article, an experimental procedure developed to estimate the thermal conductance at the part–Tool Interface during a hot stamping procedure is presented. The Tools set (punch and die) has been designed to form omega-shaped samples. This work represents the first stage of the procedure development where the standard experiment is a simple compressive load of sample in the bottom of the omega-shape die, considering the real hot-stamping conditions. Tests are carried out under different contact pressure values for two different blank materials (Usibor 1500P and a mater...
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Development of Estimation Procedure of Contact Heat Transfer Coefficient at the Part–Tool Interface in Hot Stamping Process
Heat Transfer Engineering, 2011Co-Authors: Bakri Abdulhay, Brahim Bourouga, Christine Dessain, Brun Gilles, Joel WilsiusAbstract:Energy efficiency, a high level of passenger safety, and weight reduction of the vehicles still constitute the main functional elements for the design of modern car body structures. Toward this objective, the usage of advanced sheet-metal forming technologies like hot stamping of quenchable boron manganese steel is developing nowadays. Hot stamping is a combination of hot forming and simultaneously quenching and hardening of the blank. In this article, an experimental procedure developed to estimate the thermal conductance at the part–Tool Interface during a hot stamping procedure is presented. The Tools set (punch and die) has been designed to form omega-shaped samples. This work represents the first stage of the procedure development where the standard experiment is a simple compressive load of sample in the bottom of the omega-shape die, considering the real hot-stamping conditions. Tests are carried out under different contact pressure values for two different blank materials (Usibor 1500P and a mater...
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Thermal contact resistance estimation at the blank/Tool Interface: experimental approach to simulate the blank cooling during the hot stamping process
International Journal of Material Forming, 2010Co-Authors: Bakri Abdul Hay, Brahim Bourouga, Christine DessainAbstract:In the present paper, an experimental device designed and developed to estimate the thermal contact resistance (R _ C ) at the blank/Tool Interface is presented along with the simulation chain used to validate the experimental results. The designed stamping Tool is composed of a die and a punch made in Z160CDV12 steel and presenting an omega shape. Sample and Tools are thermally instrumented with thermocouples type K sheathed with silky glass, forming heat flux-meters in the most interesting locations in the Tools. Hot stamping tests are carried out under different contact pressure values covering the range from 5 to 30 MPa . Tested blank material is a C-Mn steel, named Usibor 1500P. Temperatures measurement in the Tool and the blank allow the estimation of Rc evolution for every contact pressure. Experiments were carried out in the same conditions of the industrial process. The recorded blank temperature shows systematically a slope change around 400°C; it is linked to the microstructure transformation from austenite to martensite. This metallurgical transformation is also observed on the R _ C evolution curve. Linked to the microstructure transformation, this singularity tends to vanish with increasing pressure. That is due to the increasing of the cooling velocity with the stamping pressure increasing. Results have been established as correlation of type: R _ C = R _ C ( P ) to be used for numerical simulation through Pam-Stamp and Abaqus. Experimental and numerical parameters have been compared and the small temperature difference shows the good quality of results.
Jens Twiefel - One of the best experts on this subject based on the ideXlab platform.
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Contact mechanics and friction processes in ultrasonic wire bonding - Basic theories and experimental investigations
Journal of Sound and Vibration, 2020Co-Authors: Yangyang Long, Jens Twiefel, Jörg WallaschekAbstract:Abstract Even though ultrasonic (US) wire bonding has been a popular interconnection technique in electronic packaging industry for decades, the contact and friction conditions during the bonding processes have not been well understood. In this work, the relative motion at the wire/substrate Interface and the wire/Tool Interface, and the influences of oxides and microwelds on the friction at the wire/substrate Interface are brought together to systematically and comprehensively analyze the contact and friction at the two Interfaces. Specifically for the analysis at the wire/substrate Interface, the contact was divided into three different areas where different oxide removal and microweld formation conditions exist. The theoretical analysis was then validated by real-time observations from both side and bottom view. Both analyses show that in the beginning stage, the Tool and the wire are well coupled. The wire gross-slides on the substrate and the most substantial friction takes place in the inner peripheral region. The shift of the Tool equilibrium position was experimentally observed during this stage. As the process goes on, the contact area between the wire and the substrate gets larger. Within the contact area, the oxide layer is broken into particles and then transported to the peripheral contact region. Microwelds are formed in the oxide-free areas. Sliding friction and microweld connections coexist at the wire/substrate Interface. As more oxides are removed and more microwelds are formed, the relative displacement at the wire/substrate Interface becomes smaller while the relative displacement at the wire/Tool Interface becomes larger. Finally, microwelds cover the majority of the contact. The understanding on the contact and friction during US wire bonding leads to a potential enhancement of the processes in industry production.
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a deeper understanding on the motion behaviors of wire during ultrasonic wedge wedge bonding process
International Symposium on Microelectronics, 2016Co-Authors: Yangyang Long, Folke Dencker, Marc Christopher Wurz, Armin Feldhoff, Jens TwiefelAbstract:Abstract Ultrasonic wire bonding is a dominating interconnection technique that has been applied in packaging industry for decades. The phenomena at the wire/substrate Interface and the wire/Tool Interface, however, are not clear yet. Specifically, the motion behaviors of the wire during the bonding process have to be deeply understood. In this project, the relative motion amplitudes at the wire/Tool Interface and the self-cleaning efficiency at the wire/substrate Interface are investigated via the analysis of an artificially coated layer. For each experiment, a thin layer made of a specific material was coated onto the surface of a 400 μm wire by physical vapor deposition. The change of thicknesses of the layer was observed by a scanning electron microscope after the bonding process. The results indicated a complex relative motion behavior at the wire/Tool Interface. The relative motion amplitude at the fillets contact regions is higher than that at the other contact perimeter regions while the amplitude...
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A deeper understanding on the motion behaviors of wire during ultrasonic wedge-wedge bonding process
International Symposium on Microelectronics, 2016Co-Authors: Yangyang Long, Folke Dencker, Armin Feldhoff, Marc Wurz, Jens TwiefelAbstract:Abstract Ultrasonic wire bonding is a dominating interconnection technique that has been applied in packaging industry for decades. The phenomena at the wire/substrate Interface and the wire/Tool Interface, however, are not clear yet. Specifically, the motion behaviors of the wire during the bonding process have to be deeply understood. In this project, the relative motion amplitudes at the wire/Tool Interface and the self-cleaning efficiency at the wire/substrate Interface are investigated via the analysis of an artificially coated layer. For each experiment, a thin layer made of a specific material was coated onto the surface of a 400 μm wire by physical vapor deposition. The change of thicknesses of the layer was observed by a scanning electron microscope after the bonding process. The results indicated a complex relative motion behavior at the wire/Tool Interface. The relative motion amplitude at the fillets contact regions is higher than that at the other contact perimeter regions while the amplitude at the central area is the lowest. The insignificant influence of a 200 nm aluminum oxide layer on the bonding quality demonstrated the high self-cleaning efficiency of the wedge-wedge bonding process.
Suhas S Joshi - One of the best experts on this subject based on the ideXlab platform.
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modeling of variable friction and heat partition ratio at the chip Tool Interface during orthogonal cutting of ti 6al 4v
Journal of Manufacturing Processes, 2020Co-Authors: Siddharam Mane, Shyamprasad Karagadde, Suhas S Joshi, Shiv G. KapoorAbstract:Abstract The extreme contact conditions and temperature at the Tool-chip Interface in machining make it difficult to access the region and evaluate their tribological properties. To overcome this issue, in the author's earlier work, a new ‘pin-on-workpiece’ tribometer was developed that replicates machining tribological conditions and evaluates the velocity-dependent adhesive coefficient of friction (CoF) and heat partition ratio (HPR). In this work, a 2-D finite element model for orthogonal cutting is developed using ABAQUS TM that takes into account the effect of variable CoF and HPR and assesses their effect on cutting forces and temperature. It is observed that as feed rate increases, the location of maximum temperature along chip-Tool Interface shifts from 1 mm away from the Tool-tip, to closer to the Tool-tip. Using the variable CoF, the maximum Tool temperature reduces to 490 ∘ C from 750 ∘ C using the constant friction condition. Also, using the variable CoF, the error in cutting force model is reduced to 13 % from 22 % for the constant friction model.
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modeling of chip Tool Interface friction to predict cutting forces in machining of al sicp composites
International Journal of Machine Tools & Manufacture, 2009Co-Authors: Uday A. Dabade, Dilip Dapkekar, Suhas S JoshiAbstract:Abstract In Al/SiCp metal matrix composites, in addition to machine, Tool and process-related parameters, a change in composition (size and volume fraction of reinforcement) has a influence on machining force components. In the analytical models in the literature, the effect of abrasive reinforcement particles, which affects the coefficient of friction and consequently the friction angle, has not been considered while predicting cutting forces in machining of MMCs. In this paper, chip–Tool Interface friction in machining of Al/SiCp composites has been considered to involve two-body abrasion and three-body rolling caused due to presence of reinforcements in composites. The model evaluates resulting coefficient of friction to predict the cutting forces during machining of Al/SiCp composites using theory of oblique cutting. Further, the model considers various frictional forces on the wiper geometry on the cutting edge that has been found to improve the integrity of machined surface on composites. The predicted cutting force values were found to agree well with the corresponding experimental values for finer reinforcements composites with the assumption that 40% of the reinforcement particles contribute to the abrasion at chip–Tool Interface. However, for the coarser reinforcement composites, assumption that the 60% of the particles contribute to the abrasion yields better results.
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Modeling of chip–Tool Interface friction to predict cutting forces in machining of Al/SiCp composites
International Journal of Machine Tools and Manufacture, 2009Co-Authors: Uday A. Dabade, Dilip Dapkekar, Suhas S JoshiAbstract:Abstract In Al/SiCp metal matrix composites, in addition to machine, Tool and process-related parameters, a change in composition (size and volume fraction of reinforcement) has a influence on machining force components. In the analytical models in the literature, the effect of abrasive reinforcement particles, which affects the coefficient of friction and consequently the friction angle, has not been considered while predicting cutting forces in machining of MMCs. In this paper, chip–Tool Interface friction in machining of Al/SiCp composites has been considered to involve two-body abrasion and three-body rolling caused due to presence of reinforcements in composites. The model evaluates resulting coefficient of friction to predict the cutting forces during machining of Al/SiCp composites using theory of oblique cutting. Further, the model considers various frictional forces on the wiper geometry on the cutting edge that has been found to improve the integrity of machined surface on composites. The predicted cutting force values were found to agree well with the corresponding experimental values for finer reinforcements composites with the assumption that 40% of the reinforcement particles contribute to the abrasion at chip–Tool Interface. However, for the coarser reinforcement composites, assumption that the 60% of the particles contribute to the abrasion yields better results.