Investigation of microstructure and tribological properties of CoFeNi1.5VZrx eutectic high entropy alloys optimized by tunning Zr content

Abstract

This study investigates the influence of Zr on the microstructural evolution, mechanical and tribological properties of CoFeNi1.5VZrx (x = 0–0.6) eutectic high entropy alloys (EHEAs). The main composition evolutes from single FCC to FCC and Laves phase with increasing Zr content. Simultaneously, the microstructure changed from hypoeutectic to eutectic and then to hypereutectic with decreasing in grain size. The increase in Zr content improves the wear resistance of EHEAs at 25–800 °C. The rise in strength and hardness is the main reason for improved room-temperature wear resistance of EHEAs. The formation of gradient nano-tribo-layer and the transformation of the wear subsurface layer components from the FCC phase to the highly wear-resistant Laves phase help to enhance the high-temperature wear resistance of the EHEAs.