摘要
通过ＴＥＭ及ＳＥＭ分析研究了Ｃｕ－２５．９ｗｔ％ｚｎ－４ｗｔ％Ａｌ合金在２００～１００℃范围内等温过程中析出相的形态及内部结构的变化。初生α＿１片（贝氏体）有生长台阶，内部无层错。在其生长的第二阶段出现层错，界面处有生长台阶。第三阶段界面弯曲，层错逐渐消失，代之以位错网。片状α＿１逐步转变为块状平衡α相。实验证明，α＿１片的相变特征与各种切变长大机制不符，属扩散控制的台阶长大机制。
The morphology and fine structure of α_1 plate (bainite)in Cu-25.9%Zn-4Al alloy during isothermal transformation (from 2 00℃ to 400 ℃ ) were investigated by TEM and SEM. The growth ledges structure without stacking faults was found in the initial α_1 p1ates. But in the second growth stage the stacking faults in α_1 plates and the growth ledges in interface were dcveloped. During the third stage of growth the in terfaCe beeame wavy and the stacking faults dlsappored gradually, replaced by dislocation network,that is,plate like α_1 transformed to equllibrium rnass-like αThe experimen tresults show that the transformation characteristic of α_1 plates is inconsistent with variolis shear mechan ism of growth,but in agreement with diffusion-α_1 plates is inconsistent with various shear mechanism of 8rowth,but in agreement with dlffusion- controlled ledge mechanism.
关键词
钢锌铝合金
贝氏体
相变
Cu-Zn-Al alloy, bainite, phase transformation mechanism
