The effect of die forging on the microstructure evolution and deformation behavior of metastable β-titanium alloy Ti55511 was investigated by electron backscatter diffraction.Before die forging,the alloy Ti55511 was ...The effect of die forging on the microstructure evolution and deformation behavior of metastable β-titanium alloy Ti55511 was investigated by electron backscatter diffraction.Before die forging,the alloy Ti55511 was subjected to multi-pass forging to optimize the microstructural heterogeneity(texture)which can cause mechanical behavior anisotropy of titanium alloys.Results show that after die forging,Ti55511 components exhibit different microstructures and textures in different local areas.No<100>fiber texture is found in all areas with different degrees of deformation.Dynamic recrystallization occurs in the area where large strain occurs during the early stage of die forging.Basket-weave microstructure forms in most local areas.展开更多
The finite element analysis was applied to evaluate the respective influences of die geometry and process conditions on plastic strain distribution for β-titanium (Ti-13V11Cr3Al) alloy during the equal channel angula...The finite element analysis was applied to evaluate the respective influences of die geometry and process conditions on plastic strain distribution for β-titanium (Ti-13V11Cr3Al) alloy during the equal channel angular extrusion (ECAE). It was found that optimum equal channel angular extrusion die geometry is strongly material dependent. Optimal strain homogeneity in the Ti-13V11Cr3Al alloy may be achieved at r (inner radius)=5 mm, R (outer radius)=3 mm. The equivalent plastic strain increases with increasing friction coefficient. And the better homogeneity of the equivalent plastic strain distribution can be achieved when friction coefficient value is lower. The faster the ram speed is, the lower the homogeneity of the equivalent plastic strain distribution is and the influence is slight. The back-pressure does not help to improve the plastic strain homogeneity, and the increasing temperature has a slightly favourable effect on the plastic strain homogeneity between 400 and 600 ℃.展开更多
To develop novel β-type biomedical titanium alloys,a series of Ti-15Mo-xNb alloys（x=0,5,10 and 15,mass fraction in%） were designed and prepared by using vacuum arc melting method.The present study focused on the ef...To develop novel β-type biomedical titanium alloys,a series of Ti-15Mo-xNb alloys（x=0,5,10 and 15,mass fraction in%） were designed and prepared by using vacuum arc melting method.The present study focused on the effect of Nb addition on the microstructure,mechanical properties and castability of Ti-15 Mo alloy.Phase analysis and microstructure observation show that all the alloys consist of single β phase and the equiaxed β grain is refined with increasing Nb content.These β-type Ti-15Mo-xNb alloys exhibit good plasticity and rather low compression elastic modulus（in the range of 18.388-19.365 GPa）.After Nb addition,the compression yield strength of the alloys increases.With increasing Nb content,the micro-hardness of the alloys decreases.The alloys exhibit obvious fibrous strip microstructure after cold compression deformation.The castability test shows that the castability of the alloys after Nb addition decreases and that of the Ti-15 Mo alloy is the highest（92.01%）.展开更多
基金National Science and Technology Project of China(JPPT-135-GH-2-017)Fellowship of China Postdoctoral Science Foundation(2022M720399)。
文摘The effect of die forging on the microstructure evolution and deformation behavior of metastable β-titanium alloy Ti55511 was investigated by electron backscatter diffraction.Before die forging,the alloy Ti55511 was subjected to multi-pass forging to optimize the microstructural heterogeneity(texture)which can cause mechanical behavior anisotropy of titanium alloys.Results show that after die forging,Ti55511 components exhibit different microstructures and textures in different local areas.No<100>fiber texture is found in all areas with different degrees of deformation.Dynamic recrystallization occurs in the area where large strain occurs during the early stage of die forging.Basket-weave microstructure forms in most local areas.
基金Item Sponsored by National High-Tech Research and Development Program (863 Program) of China (2006AA03A204)Postdoctoral Science Foundation of Central South University of China (BSH201115)Youth Scientific Research Foundation of Central South University of Forestry Technology of China (QJ2010001A)
文摘The finite element analysis was applied to evaluate the respective influences of die geometry and process conditions on plastic strain distribution for β-titanium (Ti-13V11Cr3Al) alloy during the equal channel angular extrusion (ECAE). It was found that optimum equal channel angular extrusion die geometry is strongly material dependent. Optimal strain homogeneity in the Ti-13V11Cr3Al alloy may be achieved at r (inner radius)=5 mm, R (outer radius)=3 mm. The equivalent plastic strain increases with increasing friction coefficient. And the better homogeneity of the equivalent plastic strain distribution can be achieved when friction coefficient value is lower. The faster the ram speed is, the lower the homogeneity of the equivalent plastic strain distribution is and the influence is slight. The back-pressure does not help to improve the plastic strain homogeneity, and the increasing temperature has a slightly favourable effect on the plastic strain homogeneity between 400 and 600 ℃.
基金Project(QN2010-04)supported by the Youth Startup Fund of the Second Affiliated Hospital of Harbin Medical University,ChinaProject(2010-156)supported by the Medical Scientific Research Foundation of Heilongjiang Province Health Department,ChinaProject(HIT.NSRIF.2012002)supported by the Fundamental Research Funds for the Central Universities,China
文摘To develop novel β-type biomedical titanium alloys,a series of Ti-15Mo-xNb alloys（x=0,5,10 and 15,mass fraction in%） were designed and prepared by using vacuum arc melting method.The present study focused on the effect of Nb addition on the microstructure,mechanical properties and castability of Ti-15 Mo alloy.Phase analysis and microstructure observation show that all the alloys consist of single β phase and the equiaxed β grain is refined with increasing Nb content.These β-type Ti-15Mo-xNb alloys exhibit good plasticity and rather low compression elastic modulus（in the range of 18.388-19.365 GPa）.After Nb addition,the compression yield strength of the alloys increases.With increasing Nb content,the micro-hardness of the alloys decreases.The alloys exhibit obvious fibrous strip microstructure after cold compression deformation.The castability test shows that the castability of the alloys after Nb addition decreases and that of the Ti-15 Mo alloy is the highest（92.01%）.
