Tribology behavior in laser cladded dual-phase AlxCoCrFeNiMn(1-x) high entropy alloys influenced by hierarchical interface architecture

Dual-phase high-entropy alloys (HEAs), having the potential to overcome the strength-plasticity trade-off, are expected to possess exceptional tribological properties in a wide temperature range. AlxCoCrFeNiMn(1−x) (x = 0 to 1.0) HEA coatings were synthesized by laser cladding to explore the microstructural evolution and dry sliding wear behavior of the HEA coatings with dual solid-solution phases. The significant improvement in microhardness at x = 0.8 is attributed to the dual-phase microstructure featured by the hierarchical interface architecture and multi-scale dislocation network. The wear resistance of single-phase coatings with body-centered cubic (BCC) or face-centered cubic (FCC) lattice is better than that of dual-phase coatings at room temperature. At 20 °C, the volume wear rate reaches 4.54 × 10−5 mm3/(N·m) at x = 0 and 7.19 × 10−4 mm3/(N·m) at x = 0.6. Nevertheless, dual-phase coatings have better high-temperature wear resistance than single-phase coatings. At 600 °C, the volume wear rate is 7.24 × 10−5 mm3/(N·m) at x = 0 and 5.13 × 10−5 mm3/(N·m) at x = 0.6. The abundant interfaces and high-density dislocations provide oxygen element fast channels to migrate and diffuse and then facilitate the formation of an enamel layer that improves high-temperature wear resistance. This paper offers a novel avenue for the design of dual-phase HEA coating for high-temperature wear resistance.