Semisolid mold forging is a major type of semisolid processing, which isdifferent from neither traditional mold forging nor traditional permanent casting. However,processing defects are often seen in work pieces becau...Semisolid mold forging is a major type of semisolid processing, which isdifferent from neither traditional mold forging nor traditional permanent casting. However,processing defects are often seen in work pieces because of lacking available rules for the processdesign and control. Some basic rules for the process design and control, simply named the shortestflowing length, pressure filling and the minimum uplifting mold pressure, are advanced in the paperbased on amount of researches and experiments. The equations to determine the major processparameters are given out such as the filling pressure, forming pressure and locking mold pressurefor the process design and control. The rules and equations are experimentally proved available andapplicable by several actual work pieces produced by the semisolid forging process.展开更多
Quick material change is often encountered for the different colors or kinds of polymer in hot runner injecting molding process. Time costing and incompleteness of material change process often affects the quality and...Quick material change is often encountered for the different colors or kinds of polymer in hot runner injecting molding process. Time costing and incompleteness of material change process often affects the quality and productivity of products. In the practical production, multi injection or white material as the transition material is often adopted for quick material change. Based on the rheological behavior of the new and the previous plastic melt, the researches on the related problems were carried out. The concept of drag material change was originally presented. The physical and mathematical model on the simultaneous flow process of the new and the previous plastic melt in hot runner were built up, which can well explain the influence of the injection speed, pressure, viscosity difference, temperature and mold structure on the drag material change efficiency. When temperature in different position in the mold was increased and adjusted, the viscosity difference between the two kinds of melt can be controlled. Therefore the material change ability can be greatly improved during the whole material change process, getting rid of more and more difficult changing in the late stage.展开更多
Efective Selective Laser Melting(SLM)molding methods for femur implant design and molding can improve femur implant surgerysucess rates and enhance patients quality of life.In this study,an individualized femur implan...Efective Selective Laser Melting(SLM)molding methods for femur implant design and molding can improve femur implant surgerysucess rates and enhance patients quality of life.In this study,an individualized femur implant and individualized biological fixed-typefenur implant were designed using the parametric modeling method.The implants were then directly manufactured via SLM moldingtechnology as the forming process was carefuly analyzed.The results indicate that the proposed implant allows for favorable conjunctionof the reconstructed implant model with the surrounding bone tissues under the premise of a relatively small amount of bone-cutting.Theproposed implant also shows even pore distribution,good overall connectivity,relatively high bearing capacity,favorable overlappingbetween supports,and strong inter-pore connectivity.Only a small amount of powder adheres onto the surface and can be directly usedafter simple sand blasting and polishing.The comprehensive analyses of fenur implant modeling and molding methods given in this papermay provide a sound foundation for the design and direct manufacture of individualized femur implants in the future.展开更多
文摘Semisolid mold forging is a major type of semisolid processing, which isdifferent from neither traditional mold forging nor traditional permanent casting. However,processing defects are often seen in work pieces because of lacking available rules for the processdesign and control. Some basic rules for the process design and control, simply named the shortestflowing length, pressure filling and the minimum uplifting mold pressure, are advanced in the paperbased on amount of researches and experiments. The equations to determine the major processparameters are given out such as the filling pressure, forming pressure and locking mold pressurefor the process design and control. The rules and equations are experimentally proved available andapplicable by several actual work pieces produced by the semisolid forging process.
文摘Quick material change is often encountered for the different colors or kinds of polymer in hot runner injecting molding process. Time costing and incompleteness of material change process often affects the quality and productivity of products. In the practical production, multi injection or white material as the transition material is often adopted for quick material change. Based on the rheological behavior of the new and the previous plastic melt, the researches on the related problems were carried out. The concept of drag material change was originally presented. The physical and mathematical model on the simultaneous flow process of the new and the previous plastic melt in hot runner were built up, which can well explain the influence of the injection speed, pressure, viscosity difference, temperature and mold structure on the drag material change efficiency. When temperature in different position in the mold was increased and adjusted, the viscosity difference between the two kinds of melt can be controlled. Therefore the material change ability can be greatly improved during the whole material change process, getting rid of more and more difficult changing in the late stage.
基金funded by the Henan Provincial Science and Technology Project(212102310859)the Start-up Funds for High Level Talents of Zhoukou Normal University(ZKNUC 72019).
文摘Efective Selective Laser Melting(SLM)molding methods for femur implant design and molding can improve femur implant surgerysucess rates and enhance patients quality of life.In this study,an individualized femur implant and individualized biological fixed-typefenur implant were designed using the parametric modeling method.The implants were then directly manufactured via SLM moldingtechnology as the forming process was carefuly analyzed.The results indicate that the proposed implant allows for favorable conjunctionof the reconstructed implant model with the surrounding bone tissues under the premise of a relatively small amount of bone-cutting.Theproposed implant also shows even pore distribution,good overall connectivity,relatively high bearing capacity,favorable overlappingbetween supports,and strong inter-pore connectivity.Only a small amount of powder adheres onto the surface and can be directly usedafter simple sand blasting and polishing.The comprehensive analyses of fenur implant modeling and molding methods given in this papermay provide a sound foundation for the design and direct manufacture of individualized femur implants in the future.
