.7.1 NATURE OF PLASTIC DEFORMATIONPlastic deformation is the deformation which is permanent and beyond the elastic rang of the material of ten , metals are worked by pfastic deformation because of the beneficial effect that is imparted to the mechanical properties by it. The necessary deformation in a metal can be achieved by application of large amount of mechanical force only or by heating the metal and then applying a small force.7.1 塑性变形本质塑性变形是超过弹性变形范围之后的一种永久变形。通常，金属采用塑性变形加工是因为可以通过其获
