Interphase Boundary Structure and Transformation Mechanism of Phase Transformations in Solids

用常规和高分辨电子显微镜研究了包括扩散相变(沉淀)和马氏体相变产物在内的界面原子结构。围绕析出物片层和马氏体片层的界面都是半共格的。因此，在每种类型的相变中，保持了原子位的对应。在扩散相变(析出)中，生长台阶的形核和迁移由替代溶质原子的扩散控制，导致相变位错的虚拟位移。它还伴随着静止失配位错的攀升和滑行的调节位错的滑动。因此，沉淀/基质边界的迁移是一个非保守的过程。另一方面，马氏体和基体之间的界面是完全光滑的，因此可以保守地移动。

The atomic structure of the interphase boundaries enclosing the products of diffusional transformations (precipitation) and martensitic transformations was examined by means of conventional and high-resolution transmission electron microscopy. The interphase boundaries enclosing the precipitates plate and the martensite plate are both semi-coherent. Thus, in each type of phase transformations, an atomic site correspondence is maintained. In diffusional transformations (precipitation) , the nucleation and migration of growth ledges, which are controlled by diffusion of substitutional solute atoms, result in the vitual displacement of transformation dislocations. It also accompanies the climb of sessile misfit dislocations and the glide of glissile accommodation dislocations simultaneously. Thus, the migration of the precipitate/matrix boundary is a non-conservative process. On the other hand, theinterphase boundary between the martensite and the matrix is fully glissile and, thus, can move conservatively.