微量添加元素对Monel K—500合金的高温塑性的作用

发现微量Ｍｇ，Ｃｒ和Ｃｏ元素对Ｍｏｎｅｌ Ｋ－５００型的高温塑性具有明显的改善作用，实验合金在高温下表现出一定的超塑性。测定了超塑性的应变速率敏感指数ｍ值和形变激活能，发现合金在超塑性变形时激活艰较低，超塑性变形可能是一个扩散所控制的过程。

Effects of Minor Additive Elements on the High temperature Plasticity of Monel K 500 Alloy

Monel K 500 alloy has been modified by adding a small amount of Mg,Cr and Co elements to improve the mechanical property The test results show that the high temperature plasticity of the experimental alloy is much higher than the commercial Monel K 500 alloy and superplasticity appears at high temperature The index m of strain rate sensitivity and the activation energy Q of high temperature deformation were measured It is found that Q is small in the superplastic condition,It is suggested that the superplastic deformation is a diffusion controlled process The influence of Mg,Cr,Co additions on the fracture energy of the grain boundary has been calculated The results show that these minor elements increase the adhesion energy of grain boundary ,so the high temperature plasticity of Ni Cu base alloy is improved.