Molecular dynamics study on nanoscale scratch characteristics of FeNiCrCoAl high-entropy alloy

Abstract

The preparation process of FeNiCrCoAl high-entropy alloy at the atomic scale was simulated using molecular dynamics, and its microstructure was analyzed to study its micro-mechanical properties during nanoscale scratching. The simulation results showed that FeNiCrCoAl primarily experienced main frictional forces from the [010] direction and radial frictional forces from the [001] direction during the nanoscale scratching process. All three frictional forces exhibited certain fluctuations, which were partly attributed to the formation of face-centered cubic and hexagonal close-packed atomic structures during frictional wear. In addition, plastic flow was observed continuously within the high-entropy alloy matrix. Furthermore, the effects of temperature and Fe atomic content on the nanoscale scratch characteristics of FeNiCrCoAl high-entropy alloy were investigated. The results indicated that an increase in temperature resulted in a nonlinear decrease in frictional forces and a reduction in the quantity of the two types of phase-transition atomic structures formed. Increasing the Fe atomic content induced lattice distortion effects in the high-entropy alloy, leading to an increase in the potential energy of the matrix and the formation of more phase-transition atomic structures, thus hindering the frictional wear process of FeNiCrCoAl high-entropy alloy.