塑性变形 If a material deforms plastically,it changes its shape. Correspondingly,the atoms of a crystal have to change their positions. (a) (b) 内件T子工程学院 20 School of Materials Science and Engineering材料科学与工程学院 School of Materials Science and Engineering 20 If a material deforms plastically, it changes its shape. Correspondingly, the atoms of a crystal have to change their positions. 塑性变形