Plaston?Elemental Deformation Process Involving Cooperative Atom Motion
Plaston?Elemental Deformation Process Involving Cooperative Atom Motion
复制标题
涉及原子协同运动的塑性元素变形过程
DOI：
10.1007/978-981-16-7715-1_6
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Kishida Kyosuke
中科院分区：
文献类型：
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作者：
Inui Haruyuki;Kishida Kyosuke
人们对同时具有高强度和高延展性/韧性的结构材料的需求不断增加。然而，在任何材料中都很难实现这一点，因为强度和延展性通常处于权衡关系中。高强度的材料通常表现出低延展性/韧性（如在许多陶瓷中），反之亦然。晶体材料的塑性变形通常是通过沿着某一特定晶面的剪切变形来实现的（称为滑移），使得晶体的一部分相对于另一部分发生剪切（通过称为“滑移矢量”的矢量）（称为“滑动面”），这种滑动通常是（在许多情况下）由称为"位错"的晶格缺陷携带，它被定义为晶面（滑移面）上滑移区和非滑移区之间的边界（线缺陷）（图6.1）。位错可以在所施加的剪切应力下在滑移面上移动，通过称为“伯格斯矢量”的矢量使晶体的一部分相对于另一部分移位。如果移动位错所需的应力高，则材料的强度高，但由于位错运动的困难，延展性低。相反，如果移动位错所需的应力较低，则材料的强度较低，但由于位错运动的容易性，延展性较高。位错是一种线缺陷，其特征在于伯格斯矢量和线矢量。根据定义，晶体中沿着位错线的一部分的所有原子都是
There is an ever-increasing demand for structural materials that simultaneously possess high strength and high ductility/toughness. It is, however, very difficult to achieve this in any material because strength and ductility are in general in the trade-off relationship. The material of high strength generally exhibits low ductility/toughness (as in many ceramics) and vice versa. Plastic deformation of crystalline materials usually occurs by shear deformation along a particular crystallographic plane (referred to as slip) so that the shearing of one portion of a crystal occurs with respect to another (by the vector called ‘slip vector’) upon the crystallographic plane (called ‘slip plane’), and such slip is usually (in many cases) carried by a lattice defect called ‘dislocation’, which is defined as the boundary (line defect) between slipped and unslipped regions on the crystallographic plane (slip plane)(Fig. 6.1). The dislocation can move on the slip plane under the exerted shear stress, displacing one portion of a crystal with respect to another by the vector called ‘Burgers vector’. If the stress required to move dislocations is high, the strength of the material is high but the ductility is low because of the difficulty in the dislocation motion. If the stress required to move dislocations is low, in contrast, the strength of the material is low but the ductility is high due to the ease in the dislocation motion.‘Dislocation’is a line defect characterized by the Burgers vector and line vector. By definition, all atoms of one portion of a crystal along the dislocation line are