Effect of oxidation on mechanical properties of Fe-Ni alloys: Atomic insights from ReaxFF molecular dynamics simulations

Oxidation can have a significant effect on mechanical properties, depending on the degree of oxidation, temperature, alloy type and strain rate which has been widely investigated by experiments and computational analysis. The accuracy of the ReaxFF potential has been first verified using DFT comparison and applied to describe the oxidation process of the Fe25Ni75 alloy. A high temperature is essential to increase the degree of oxidation and accelerate the oxidation rate. During tensile tests, the phase transformation from FCC to BCC occurs and the resulting change in mechanical properties is classified as transformation induced plasticity. The distribution of dislocations suggests the main region where the phase transformation occurs, and the structural distortion due to oxidation may be the trigger for the phase transformation. These findings provide a novel perspective to explore the effects of oxidation on the mechanical properties of alloys from an atomistic perspective.