The micromechanical behavior of a recently developed TiNb/NiTi composite during a pre-straining process was investigated to broaden the understanding of deformation mechanisms of the martensitic-transforming composite...The micromechanical behavior of a recently developed TiNb/NiTi composite during a pre-straining process was investigated to broaden the understanding of deformation mechanisms of the martensitic-transforming composites.It was found that during loading,besides inherent elastic elongation,the TiNb/NiTi composite also experienced two different categories of stress-induced martensitic transformations(SIMTs,including B2→B19’andβ→α")and slight plastic deformation.Upon the following unloading,this composite recovered elastically,and underwent simultaneously a fully reversibleα"→βSIMT as well as a partially reversible B19’→B2 SIMT.It was the incomplete B19’→B2 SIMT and the permanent plastic deformation that led to the~4.6%macroscopic residual strain after unloading.In the entire loading-unloading procedure,the growth and shrinkage of(001)compound twins in B19’martensite also contributed to the large nearlinear-elastic deformation of the present composite.展开更多
基金financially supported by the National Natural Science Foundation of China(No.52175410)the Six Talent Peaks Project in Jiangsu Province(No.2019-XCL-113)+1 种基金Zhenjiang Science&Technology Program(No.GY2020001)the Project of Faculty of Agricultural Equipment of Jiangsu University(No.NZXB20200101)。
文摘The micromechanical behavior of a recently developed TiNb/NiTi composite during a pre-straining process was investigated to broaden the understanding of deformation mechanisms of the martensitic-transforming composites.It was found that during loading,besides inherent elastic elongation,the TiNb/NiTi composite also experienced two different categories of stress-induced martensitic transformations(SIMTs,including B2→B19’andβ→α")and slight plastic deformation.Upon the following unloading,this composite recovered elastically,and underwent simultaneously a fully reversibleα"→βSIMT as well as a partially reversible B19’→B2 SIMT.It was the incomplete B19’→B2 SIMT and the permanent plastic deformation that led to the~4.6%macroscopic residual strain after unloading.In the entire loading-unloading procedure,the growth and shrinkage of(001)compound twins in B19’martensite also contributed to the large nearlinear-elastic deformation of the present composite.