Taking half-tube part with curvature as an example,the Impact Hydroforming(IHF)characteristics were studied by combining the actual forming experiment and numerical simulation.The IHF experiment showed that wrinkles a...Taking half-tube part with curvature as an example,the Impact Hydroforming(IHF)characteristics were studied by combining the actual forming experiment and numerical simulation.The IHF experiment showed that wrinkles appeared at the bottom of the part during single-step forming,but no wrinkles were observed during double-step forming.The thinning rate and deviation of the wall thickness of the part in each area were less than 20%and 2.7 mm,correspondingly,and the drawing depth of the part reached 45.8 mm.The effect of double-step forming was better than that of single-step forming,which was related to the IHF forming law.Besides,the characteristics of the IHF process were studied by numerical simulation.The results indicated that when double-step forming was utilized,there was almost no velocity field in the opposite direction of deformation after the bottom of the part contacted the die,and the existence of stress state at the bottom would restrain and eliminate the wrinkles.The inertia effect evolved with the driving pressure.Specially,the inertia effect can improve the flow of metal and reduce the deviation of the wall thickness of the part under double-step forming.展开更多
A novel method called thermomechanical treatment based on impact hydroforming(TTIHF)was proposed.The pre-deformation was achieved by using impact hydroforming(IHF)loading.The strengthening effect and mechanism of 2195...A novel method called thermomechanical treatment based on impact hydroforming(TTIHF)was proposed.The pre-deformation was achieved by using impact hydroforming(IHF)loading.The strengthening effect and mechanism of 2195 Al-Li alloy were investigated under various loading pre-deformation conditions.The results showed that the time for the alloy to reach peak aging was shortened under TTIHF.Compared with those of the pre-deformation method of stamping forming,the yield strength and tensile strength of the Al-Li alloy under TTIHF increased by 18.6%and 18.0%,respectively.The deformation caused by IHF loading resulted in a high density of dislocations,which served as nucleation sites for the precipitation of the T_(1)phase during aging.After TTIHF,the average diameter and thickness of the T_(1)phase in the alloy were smaller than those under other experiment conditions.Moreover,the density and distribution of the T_(1)phase were the highest and the most uniform.展开更多
基金financially supported by the National Key R&D Program of China(No.2024YFE0108800/T24KITG014)the National Natural Science Foundation of China(No:52475411)the International Partnership Program of Chinese Academy of Sciences(No.172GJHZ2022096FN)。
文摘Taking half-tube part with curvature as an example,the Impact Hydroforming(IHF)characteristics were studied by combining the actual forming experiment and numerical simulation.The IHF experiment showed that wrinkles appeared at the bottom of the part during single-step forming,but no wrinkles were observed during double-step forming.The thinning rate and deviation of the wall thickness of the part in each area were less than 20%and 2.7 mm,correspondingly,and the drawing depth of the part reached 45.8 mm.The effect of double-step forming was better than that of single-step forming,which was related to the IHF forming law.Besides,the characteristics of the IHF process were studied by numerical simulation.The results indicated that when double-step forming was utilized,there was almost no velocity field in the opposite direction of deformation after the bottom of the part contacted the die,and the existence of stress state at the bottom would restrain and eliminate the wrinkles.The inertia effect evolved with the driving pressure.Specially,the inertia effect can improve the flow of metal and reduce the deviation of the wall thickness of the part under double-step forming.
基金financially supported by the National Key R&D Program of China(Nos.2024YFE0108800,T24KITG-014)the International Partnership Program of Chinese Academy of Sciences(No.172GJHZ2022096FN)。
文摘A novel method called thermomechanical treatment based on impact hydroforming(TTIHF)was proposed.The pre-deformation was achieved by using impact hydroforming(IHF)loading.The strengthening effect and mechanism of 2195 Al-Li alloy were investigated under various loading pre-deformation conditions.The results showed that the time for the alloy to reach peak aging was shortened under TTIHF.Compared with those of the pre-deformation method of stamping forming,the yield strength and tensile strength of the Al-Li alloy under TTIHF increased by 18.6%and 18.0%,respectively.The deformation caused by IHF loading resulted in a high density of dislocations,which served as nucleation sites for the precipitation of the T_(1)phase during aging.After TTIHF,the average diameter and thickness of the T_(1)phase in the alloy were smaller than those under other experiment conditions.Moreover,the density and distribution of the T_(1)phase were the highest and the most uniform.
