周 体心立方 (a) (b) BCC 尽 Body-centered cubic a 2a 材料科学与工程学院 6 3a=4R (c) School of Materials Science and Engineering
材料科学与工程学院 School of Materials Science and Engineering 体心立方 6 4R a 3a 2a 3a =4R (c) (a) (b) BCC Body-centered cubic
图 面心立方 (a) (b) FCC Face-centered cubic 4R②a 2a=4R (c) 材料科学与工程学院 7 School of Materials Science and Engineering
材料科学与工程学院 School of Materials Science and Engineering 面心立方 7 (a) (b) (c) a 4R 2a 2a = 4R FCC Face-centered cubic
图 六排密方 a hexagonal (a) (b) HCP center of atom at 211 33 Hexagonal close-packed center of atom located in next unit cell 12of an atom (c) 1 材料科学与工程学院 6 of an atom 8 School of Materials Science and Engineering
材料科学与工程学院 School of Materials Science and Engineering 8 (c) (a) (b) hexagonal c a center of atom located in next unit cell center of atom at 2 1 , 3 1 , 3 2 of an atom 12 1 6 of an atom 1 六排密方 HCP Hexagonal close-packed
周 结构材料 强度 韧性 The strength of a material is Toughness is the ability of a its ability to withstand an material to absorb energy and applied load without failure. plastically deform without fracturing. energy stress o=F/A = a de volume yield fracture X non-linear area o=f(E) linear area O=EE strain E > 材料科学与工程学院 9 School of Materials Science and Engineering
材料科学与工程学院 School of Materials Science and Engineering 结构材料 9 • The strength of a material is its ability to withstand an applied load without failure. 强度 • Toughness is the ability of a material to absorb energy and plastically deform without fracturing. 韧性
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) 件件子习工程学院 10 School of Materials Science and Engineering
材料科学与工程学院 School of Materials Science and Engineering 10 If a material deforms plastically, it changes its shape. Correspondingly, the atoms of a crystal have to change their positions. 塑性变形