图 塑性变形 Debye-Scherrer diagrams of (a) (a)undeformed and(b)deformed copper (a) (b) (b) (c) Plastic deformation of a specimen under tensile stress by slip.(a)Before deformation;(b)after deformation;(c) stretched in single crystal. 材料科学与工程学院 21 School of Materials Science and Engineering材料科学与工程学院 School of Materials Science and Engineering 塑性变形 21 Debye-Scherrer diagrams of (a) undeformed and (b) deformed copper Plastic deformation of a specimen under tensile stress by slip. (a) Before deformation; (b) after deformation; ( c) stretched in single crystal