Study on texture memory effect in nickel aluminide

在退火的早期阶段，重冷轧的镍铝化物单晶的尖锐织构被分解，但它最终返回到尖锐织构，这与冷轧状态非常相似。这种有趣的现象被称为纹理记忆效应。最近，我们发现，没有织构记忆效应发生在两相合金，其中镍铝化物是共格沉淀在镍固溶体基体。本研究的目的是阐明织构记忆效应发生的必要因素。首先，我们证实了镍固溶体单相中不存在织构记忆效应。通过电镜分析，我们认为织构记忆效应的产生有两个条件：（1）冷轧过程中积累了足够的应变;（2）晶界自由移动，没有界面等障碍物。

A sharp texture of heavily cold-rolled nickel aluminide single crystals is disintegrated in an early stage of annealing, but it finally returns to the sharp texture, which is very similar to that in the cold-rolled state. This interesting phenomenon is termed as texture memory effect. Recently, we found that no texture memory effect occurs in two-phase alloys, where the nickel aluminide is coherently precipitated in a nickel solid-solution matrix. This study aimed to clarify factors necessary for the occurrence of the texture memory effect.Firstly, we confirmed that no texture memory effect occurs in a nickel solid-solution single phase. Based on the electron microscopic analyses, we concluded that there are two requisites for the occurrence of the texture memory effect: (1) enough strain is accumulated in the cold rolling process and (2) grain boundary move freely with no obstacles like intereface.