可压缩粉末烧结材料塑性变形与屈服条件

The plastic deformation and yield criterion for compressible sintered powder mat erials

本文分析了粉末烧结材料塑性变形的基本规律 ,指出了现有粉末烧结材料屈服条件与实际情况不相符的问题。通过烧结铜圆柱体试样单向压缩实验 ,确定了粉末烧结材料真实应力应变关系 ,建立了普适的粉末烧结材料屈服条件和塑性本构关系。本文的屈服条件不仅用统一的函数形式表示了粉末烧结材料初始屈服和后继屈服 。

The basic plastic deformation laws of compressible s in tered powder materials such as volume change, mass constancy, small Poisson rati o, hydrostatic stress affecting on yield etc. are analyzed. The cases about pres ent yield criterion for compressible sintered powder materials violating practic e facts are pointed out. The real stress-strain equation, a general yield criter ion and plastic constitutive equations for compressible sintered powder material s are determined based on the single axial compression of sintered copper cylind er specimens. The general yield criterion, which not only reflects both the init ial yield and following yield of compressible sintered powder materials, but als o includes the effects of both initial situation and deformation densification o f compressible sintered powder materials on yield, is expressed in one unified y ield function.