The deformation characteristic in the forming process of aluminum alloy 7075 cross valve under multi-way loading was investigated by numerical simulation method. The results indicate that there exist 4 deformation pat...The deformation characteristic in the forming process of aluminum alloy 7075 cross valve under multi-way loading was investigated by numerical simulation method. The results indicate that there exist 4 deformation patterns in the multi-way loading forming process of cross valve, such as forward extrusion, backward extrusion, forward-lateral extrusion and backward-lateral extrusion; one or several patterns occur at different forming stages depending on loading path. In general, the main deformation pattern is forward extrusion or backward extrusion at the initial stage; the main deformation pattern is backward extrusion at the intermediate stage, and the backward extrusion and forward-lateral extrusion occur at the final stage. In order to improve the cavity fill and reduce the forming defects, the lateral extrusion deformation should be increased at the initial and intermediate stages, and the forward extrusion deformation at the final forging stage should be reduced or avoided.展开更多
The hot deformation behavior of a Ta-particle reinforced TiAl composite was studied.Ti-48Al-2Cr-2Nb-0.2 W(at.%)/20 vol.%Ta metal matrix composite was fabricated by spark plasma sintering.The deformation behavior was i...The hot deformation behavior of a Ta-particle reinforced TiAl composite was studied.Ti-48Al-2Cr-2Nb-0.2 W(at.%)/20 vol.%Ta metal matrix composite was fabricated by spark plasma sintering.The deformation behavior was investigated by hot compression tests at the temperature ranging from 1050 to 1200℃ and the strain rate ranging from 1×10-3 to 1 s-1.The constitutive equation containing true strain variables was established.The values of activation energy Q under different strain degrees are between 240 and 280 kJ/mol,which are lower than that of pure TiAl.Based on dynamic material modeling,the processing maps at various strain degrees were established,and the optimized parameters for hot working are 1050-1100℃ and 0.005-0.01 s-1.The microstructural evolution during deformation was characterized,which indicated that the dynamic recrystallization plays an important role in this process.展开更多
基金Project(2011ZX04016-081)supported by the National Science and Technology Major Project of China
文摘The deformation characteristic in the forming process of aluminum alloy 7075 cross valve under multi-way loading was investigated by numerical simulation method. The results indicate that there exist 4 deformation patterns in the multi-way loading forming process of cross valve, such as forward extrusion, backward extrusion, forward-lateral extrusion and backward-lateral extrusion; one or several patterns occur at different forming stages depending on loading path. In general, the main deformation pattern is forward extrusion or backward extrusion at the initial stage; the main deformation pattern is backward extrusion at the intermediate stage, and the backward extrusion and forward-lateral extrusion occur at the final stage. In order to improve the cavity fill and reduce the forming defects, the lateral extrusion deformation should be increased at the initial and intermediate stages, and the forward extrusion deformation at the final forging stage should be reduced or avoided.
基金Project(51625404)supported by the National Natural Science Foundation for Distinguished Young Scholar of China
文摘The hot deformation behavior of a Ta-particle reinforced TiAl composite was studied.Ti-48Al-2Cr-2Nb-0.2 W(at.%)/20 vol.%Ta metal matrix composite was fabricated by spark plasma sintering.The deformation behavior was investigated by hot compression tests at the temperature ranging from 1050 to 1200℃ and the strain rate ranging from 1×10-3 to 1 s-1.The constitutive equation containing true strain variables was established.The values of activation energy Q under different strain degrees are between 240 and 280 kJ/mol,which are lower than that of pure TiAl.Based on dynamic material modeling,the processing maps at various strain degrees were established,and the optimized parameters for hot working are 1050-1100℃ and 0.005-0.01 s-1.The microstructural evolution during deformation was characterized,which indicated that the dynamic recrystallization plays an important role in this process.
