扩展位错攀移的高温蠕变机制

THE MECHANISM OF HIGH TEMPERATURE CREEP ASSOCIATED WITH THE CLIMB OF EXTENDED DISLOCATIONS

本文研究了扩展位错攀移的高温蠕变机制。在文献[1]提出的扩展割阶束集模型的基础上,求出了在外加应力作用下割阶束集所需的时间和扩展位错的攀移速率,从而推导出稳态蠕变速率的表达式。根据此表达式,稳态蠕变速率与层错能的三次方成正比。这与一般实验结果相符。文中还指出了在某些情况下偏离三次方关系的可能原因。

The mechanism of high temperature creep associated with the climb of extended dislocations is investigated. Based on the model for the contraction of extended jogs [1], the time needed for the contraction under the action of applied stress and the climb velocity of extended dislocations are derived. And consequently, an expression of the steady state creep rate is obtained. According to this expression, the creep rate is shown to be proportional to the third power of the stacking fault energy. This is consistent with the majority of experimental results. The possible reason for the deviation from the third power relation in some cases is also discussed.