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利用电子显微镜研究了近等原子比TiNi合金及Fe-Ni-V-C合金中的位移型相变。研究表明:应力(包括内应力)明显地影响点阵的稳定性。张应力有利于与R相及马氏体相形核有关的软模。证实了电子衍射谱上漫散射条纹的出现是由于具有〈111〉极化的声子模软化。R相形核于Ti_(11)Ni_(14)处,其规则外形是畸变能与界面能的综合效果。Fe-Ni-V-C合金中的特殊位错组态-在长环形位错内塞积着较高密度的短位错列-是蝶状马氏体的核胚。此类位错组态提供了马氏体相变所必需的二次切变。
The phase transition of TiNi alloy and Fe-Ni-V-C alloy at near atomic ratio was studied by electron microscope. Research shows that stress (including internal stress) significantly affects the stability of the lattice. Tensile stress is beneficial to the soft molds associated with the nucleation of R phase and martensite. It was confirmed that the appearance of diffusely scattered fringes in the electron diffraction spectrum was due to softening of the phonon mode with <111> polarization. R phase nucleation at Ti_ (11) Ni_ (14), its regular shape is the combined effect of distortion energy and interface energy. The special dislocation configuration in the Fe-Ni-V-C alloy - a high density of short dislocations in the long ring dislocations - is the nuclei of butterfly martensite. This dislocation configuration provides the necessary secondary shear for martensitic transformation.