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用高压透射电镜对 Ti-54wt%Ni 形状记忆合金进行了组织观察和结构分析。结果表明材料的高温相组织为单相组织,由具有 CsCl 结构的 B_2相组成。B_2相选区电子衍射花样由衍射斑点和漫射条纹组成。漫射条纹穿过基本衍射斑点。但是不穿过中心斑点和超结构衍射斑点。倾斜样品使衍射斑点消失后,仍然可观察到漫射条纹。经冷处理的薄膜样品的组织由马氏体组成,马氏体片内含有孪晶。观察过程中,样品因被电子束照射而加热,使马氏体转变为 B_2相。转变分瞬间和连续两种方式进行。前者是分阶段进行的,表现为“万花筒”式。
High-pressure transmission electron microscopy Ti-54wt% Ni shape memory alloy were observed by microstructure and structure analysis. The results show that the high-temperature phase structure of the material is single-phase structure, consisting of B_2 phase with CsCl structure. The B 2 phase selection electron diffraction pattern consists of diffraction spots and diffuse stripes. Diffuse stripes through the basic diffraction spots. But not through the center spot and the superstructure diffraction spot. After tilting the sample so that the diffraction spots disappear, diffusion streaks are still observed. The microstructure of the cold-treated film consists of martensite and the martensite contains twins. During the observation, the sample was heated by the electron beam and transformed the martensite into the B_2 phase. Change points instantaneous and continuous two ways. The former is carried out in stages, manifested as “Kaleidoscope” type.