Nano-coupled heterostructure induced excellent mechanical and tribological properties in AlCoCrFeNi high entropy alloy

Abstract High strength, ductile and wear-resistant alloys are required for engineering applications. This work reports a good combination of mechanical and tribological properties in (NiAl)x(FeCr)yCo(x+y)/2 high-entropy alloys (HEAs) via adjusting A2/B2 nano-coupled heterostructure. The A2/B2 heterostructure switches from weave to network structure by increasing x:y ratio from 1:1.3 to 1:1, and eventually forms an island structure when x:y ratio is 1.3:1. Concurrently, the grain boundary FCC phase transforms from continuous to discontinuous as its fraction decreases. The island-like A2/B2 heterostructure provides (NiAl)1.3(FeCr)Co1.15 HEA a good compressive yield strength of 1.7 GPa and plasticity of 23.4%. Additionally, (NiAl)1.3(FeCr)Co1.15 HEA has the promising wear-resistance from room temperature to 800 °C, ascribing to its excellent strength and the protective tribo-layer at high temperatures.