Study of tribological property of laser-cladded FeCoCrNiMnx high-entropy alloy coatings via experiment and molecular dynamics simulation

Abstract

Laser cladding was used to fabricate the high entropy alloy (HEA) coating of FeCoCrNiMnx (x = 0, 0.5, 1). Coatings were studied to determine how Mn affected the microstructure, microhardness, and tribological property. Molecular dynamics simulations were used to examine the atomic-scale deformation and wear behavior of FeCoCrNiMn HEA coatings. FeCoCrNiMnx HEA coatings were composed of single FCC-type solid solution. Friction reduction and wear resistance are improved with Mn doping. When compared to the substrate and FeCoCrNi coating, the wear resistance of Mn1 coating is superior by 69.34% and 25.05%, respectively (wear rate is 3.74 ×10−5 mm3/N·m). The findings of molecular dynamics simulations demonstrate that Mn-doping significantly enhances strain hardening by the friction-induced FCC phase transition to the HCP phase. The deformation mechanism of Mn1 coating, as determined by the dislocation evolution pattern, is twinning induced plasticity, which improves the plasticity, strength, and work-hardening rate of coating all at once.