提出了关于应力时效(高温及作用应力)引起溶质原子的晶界非平衡偏聚或贫化机理的一个新模型.此模型基于如下假设:晶界相对于完整晶体而言在强度上是弱化区.当多晶体受到一个在弹性范围内的作用应力时,晶界优先变形. 若压应力作用时,晶界作为源发射空位;若拉应力作用时,晶界作为阱吸收空位.应力引起的过饱和空位与溶质原子形成复合体,此复合体在基体中的扩散速率远高于溶质原子.作用应力对晶界溶质偏聚或贫化的影响,是由复合体的扩散和溶质原子的反向扩散之间的平衡所决定.根据此模型,应力时效过程中存在一个临界时间,在此时间,应力引起的晶界偏聚或贫化程度将达到一个极大值.此模型已由Shinoda T等所作的磷在钢中的应力时效实验和Mis ra R D K所作的硫在钢中的应力时效实验结果所证实.
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