Elastic Constants and Properties of B2-type FeAl and Fe-Cr-Al Alloys from First-Principles Calculations

摘要

The elastic constants (c_(ij)) and elastic properties of B2-phase FeAl intermetallic compounds and Fe-Cr-Al ternary alloys are studied by performing first-principles density functional theory calculations. The stable structures of Fe-Cr-Al and the elastic constants of FeAl and Fe-Cr-Al are predicted within the local density approximation (LDA) and PBE formulations of the generalized gradient approximation (GGA). It is found that more precise calculations of the c_(ij) values of Fe-Cr-Al can be performed using the GGA-PBE method by comparing with experimental results. The predicted c_(ij) values of Fe-Cr-Al will help in predicting the elastic properties of Fe-Cr-Al. The electronic structures of FeAl and Fe-Cr-Al are analyzed to determine the micro mechanism of the two compounds.