价电子结构与合金元素对NiAl力学性能的影响

Effects of Valence Electron Structure and Alloying Elements on NiAl Mechanical Properties

运用固体与分子经验电子理论,计算了添加几种常用合金元素M(M=Cr,Mn,Fe,Co,Cu)的合金(NiM)Al相空间价电子结构,并采用相结构因子nA、ρLV表征和评判了合金元素M对NiAl金属间化合物塑性和硬度的影响。研究结果表明,采用宏合金化的方法虽然可以提高合金的硬度,却降低了合金的塑性。合金化后NiAl硬度增加的次序为(Ni0.875Mn0.125)Al>(Ni0.875Co0.125)Al>(Ni0.875Fe0.125)Al>(Ni0.875Cr0.125)Al>(Ni0.875Cu0.125)Al>NiAl,塑性降低次序则与硬度增加次序相反。

Based on the empirical electron theory of solid and molecule （EET）, the valence electron structure （VES） of （NiM）A1 is calculated. Several parameters of mechanical properties involved in nλ and pA^L are used to characterize and assess the effect of alloying elements on the ductility and hardness of NiA1 intermetallic compound. The results show that the addition of alloying element M can improve the hardness of NiA1 as following order： （Ni0.875Mn0.125）Al〉（Ni0.875Co0.125）Al〉（Ni0.875 Fe0.125）Al〉（Ni0.875Cr0.125）Al〉（Ni0.875 Cu0.125）Al〉NiA1. On the contrary, the ductility of NiA1 induced by alloying element M decreases as the above order.