Large elastic strains and ductile necking of W nanowires embedded in TiNi matrix

• 作 者: Daqiang Jiang Zhenghao Jia Hong Yang Yinong Liu Fangfeng Liu Xiaohua Jiang Yang Ren Lishan Cui
• 机 构: Department of Materials Science and Engineering,China University of Petroleum-Beijing,Beijing,Changp
• 出 处: 材料科学技术（英文版）
• 发表日期: 2021年1期
• 关键词: Tungsten Nanowire In-situ TEM Elastic strain

The deformation behaviors of W nanowires embedded in a TiNi matrix were investigated by means of in-situ synchrotron high energy X-ray diffraction (HEXRD) and in-situ transmission electron microscopy (TEM) analysis during tensile deformation. The HEXRD measurement indicated that the W nanowires exhibited an average lattice strain of about 1.50％, whereas the TEM examination revealed a local elastic strain of about 4.59％in areas adjacent to the TiNi matrix where stress-induced martensitic transforma-tion occurred. This strain corresponds to a stress of～ 15 GPa for the W nanowires. In addition, in areas adjacent to the TiNi matrix where plastic deformation and cracking were generated, the W nanowire showed significant ductile necking with～ 80％reduction in cross-section area. The ductile necking of W nanowire is attributed to the lack of protection from the stress-induced martensitic transformation of the TiNi matrix.