Cultivating a comprehensive understanding of microstructural attributes and wear mechanisms in FeCrCoNiAlTix high-entropy alloy coatings on TC6 substrates through laser cladding fabrication

Abstract

Titanium effectively improves the hardness of FeCrCoNiAl high-entropy alloy (HEA) coatings. In this study, FeCrCoNiAlTix (x = 0, 0.3, 0.5, 0.8, and 1.0) high-entropy alloy coatings were successfully prepared on TC6 titanium alloy substrates via laser cladding(LC). Through the preparation of LC, the effects on the microstructure, phase composition and fretting wear behavior of coatings with different Ti molar ratios were investigated in detail. The results showed that the FeCrCoNiAlTix (x = 0, 0.3) HEA coatings consisted of face-centered cubic (FCC) and body-centered cubic (BCC) phases. With increasing Ti content of the FeCrCoNiAlTix (x = 0.5, 0.8, and 1.0) HEA coatings, a new eutectic BCC2 hard phase appeared. The FCC phase was the continuous in the microstructure, whereas the BCC and BCC2 phases formed a hard skeleton. The hardness of the FeCrCoNiAlTix HEA coatings increased with increasing Ti content, and the hardness of the Ti1.0 HEA coating reached a maximum of 848 HV0.1. The FeCrCoNiAlTix (x = 0,0.3,0.5,0.8, and 1.0) HEA coatings effectively improved the resistance of TC6 alloys to fretting by fatigue, oxidative, adhesive, and abrasive wear.