CuAlMnZnZr合金拉伸变形及其宽滞后效应

Tensile Deformation of CuAlMnZnZr Alloy and its Wide Transformation Hysteresis Effect

利用拉伸试验、电阻—温度曲线测量、光镜、Ｘ射线衍射及透射电镜分析方法研究了Ｃｕ－Ａｌ１０．２－Ｍｎ４．９－Ｚｎ４．６－Ｚｒ０．３合金的宽滞后效应。结果表明，随着应变的增大，该合金相变滞后增宽，马氏体可逆转变量减少。在应力下合金组织变化如β→２Ｈ转变、１８Ｒ→２Ｈ转变、某些变体择尤长大，变体间的合并是主要变形机制。这些运动导致了交叉组织、带状组织、锯齿状边界、孪晶碎片及位错缠结的产生，破坏了变体间界面共格关系，使得其在热激活作用下难以运动。这可能是产生宽滞后效应和使可逆马氏体量减少的主要原因。

The deformation characteristic of Cu-Al10. 2-Mn4. 9-Zn4. 6-Zr0. 3 alloy and its wide transformation hysteresis effect were studied by means of tensile test, electrical resistance measurement, X ray diffraction and optical metalloscope and TEM observation. It is shown that the transformation hysteresis increases and the reversible martensite amount decreases as the increasing of the strain. The structure changes of the alloy under stress, such as β1→2H and 18R→2H transformation, preferentical growth of some variants and coalescence of variants, are main deformation mechanisms. These movements create the cross structure, band structure, serrated boundaries, twin debris and tangled dislocations, destroy the coherent boundaries between the variants and make them difficult to move under thermal activation, which may contribute its share to the wide transformation hysteresis effect and make the reversible martensite amount decrease.