Mechanical behaviour of metals
Mechanical behaviour of metals
复制标题
DOI：
10.1007/978-3-540-73448-2_6
复制
发表时间：
2007
期刊：
影响因子：
--
通讯作者：
J. Rösler;M. Bäker;H. Harders
中科院分区：
文献类型：
--
作者：
J. Rösler;M. Bäker;H. Harders
塑性变形是不可逆的。因此，在塑性变形过程中必须改变原子的构型，否则它们会在卸载时恢复到原来的位置。如果我们以剪切单晶为例，它可以通过滑动整层原子层来塑性变形，如图6.1所示。为了发生这种滑动，原子之间的键必须弹性拉伸，直到它们可以切换到下一个原子。这一过程所需的应力可以估计(见练习16)，约为晶体剪切模数的五分之一。因此，用这种方法预测的金属单晶的屈服强度在1 Gpa到25 Gpa之间。
Plastic deformation is irreversible. Therefore, the configuration of the atoms must be changed during plastic deformation, for otherwise they would return to their original position on unloading. If we consider shearing a single crystal as an example, it can be deformed plastically by sliding whole layers of atoms against each other as shown in figure 6.1. 1 For this sliding to happen, the bonds between the atoms have to be stretched elastically until they can switch to the next atom. The stress required for this process can be estimated (see exercise 16) and is of the order of one fifth of the shear modulus of the crystal. The yield strength predicted this way for metallic single crystals is thus between 1 GPa and 25 GPa.