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 11 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 11 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
图 塑性变形 “Theoretical shear strength”is much higher than observed strength values. Tmax=G/10 max Formation motion of dislocations was postulated to explain this. Dislocations can be much easier to move as applied stress just makes a few atoms move a small distance b) 材料科学与工程学院 12 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 12
③ 位错Dislocation dislocation line dislocation line Burgers vector,b b是 材料科学与工程学院 13 School of Materials Science and Engineering
材料科学与工程学院 School of Materials Science and Engineering 位错 Dislocation 13
图 位错观测 (a) TEM (c) () (b) Dislocation core C STM (a) () 材料科学与工程学院 14 School of Materials Science and Engineering
材料科学与工程学院 School of Materials Science and Engineering 位错观测 14 TEM STM
图 位错观测 10 jm b) 10 um a) c) 材料科学与工程学院 15 School of Materials Science and Engineering
材料科学与工程学院 School of Materials Science and Engineering 位错观测 15 d d d d a) b) c)