摘要
分析和计算了ｆｃｃ金属｛１１１｝<１１０>滑移和｛１１１｝<１１２>孪生的单晶共生屈服应力状态（屈服顶点），求出了相应的活化系及５个独立活化系的组合数，结果表明，只有当孪生与滑移的临界切应力之比为１／≤ξ≤２／时，滑移和孪生才可能同时发生；证明了在此范围内仅存在两种类型的屈服应力状态，并且求出了相应的解析表达式当／２＜ξ＜２／时，总共有２５９种应力状态，在应力空间按晶体结构对称性加以分类，可分为２１组；当１／＜ξ＜／２时，也有２５９种共生屈服应力状态，但分为１９组在这两种类型的屈服应力状态中，１３９种是相同的，１２０种不同，它们分别活化５；６或８个滑移或孪生系，依赖于结晶学上不等价的滑移及孪生系组。
The co-yield stress states (co-yield vertices), the corresponding active systems and the number of sets of 5 independent active systems in fee single crystal for slip on {ill}<110> and twinning on {111}<112> systems have been analyzed systematically. The results demonstrated that only if the ratio ξ of the critical resolved shear stress for twinning to that for slip is within the range of 1/3 ≤5ξ≤ 2/3, slip and twinning can occur together. There are only two types of co-yield stress states and the corresponding analytical expressions are also derived. One type consists of 259 co-yield stress states when 3/2 <ξ < 2/3, which can be classified into 21 groups in stress space and another 259 co-yield stress states as well when 1/3 < f < 3/2, which can be subdivided into 19 groups according to the crystal symmetry. Of the two types of the co-yield stress states, 139 ones are common and 120 ones are different. Each of the groups activates 5, 6 or 8 slip or twinning systems respectively, depending on crystallographically non-equivalent slip and twinning systems groups.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2000年第2期217-221,共5页
Acta Metallurgica Sinica
基金
国家自然科学基金!59971067
关键词
共生屈服顶点
滑移
孪生
应力空间
塑性变形
co-yield venice, {111} <110> slip, {111} <112> twinning, stress space, plastic deformation
