Improving microstructure and frictional wear behavior of plasma cladding FeCoCrNiMo high-entropy alloy layers by annealing treatment

The application of high-strength, wear-resistant materials for the restoration of large-scale coal development equipment is pivotal in ensuring efficient production and energy conservation within the industry. In this study, FeCoCrNiMo high-entropy alloy (HEA) cladding layers were fabricated on Q235 steel using plasma cladding techniques and subsequently subjected to annealing at 700°C, 800°C, 900°C, and 1000°C, respectively. The microstructural evolution, hardness, and wear resistance of the annealed cladding layers were thoroughly investigated. The results indicated that the microstructure of FeCoCrNiMo HEAs predominantly consisted of alternating eutectic formations of FCC, σ, and μ phases. The content of σ phase initially increased and then decreased with the increase of the annealing temperature. As the σ phase increased, both the microhardness and wear resistance were enhanced. Compared to HEA layers annealed at other temperatures, the HEA layer annealed at 900°C exhibited the highest hardness (700 HV). The wear mechanisms of the cladding layers were predominantly characterized by oxidative wear and adhesive wear. Notably, a stable oxide film was observed on the surface of the cladding layer treated at 900°C, with a wear rate as low as 1.27×10−7 mm3N−1mm−1. This study provided a technological basis and theoretical support for the repair of coal equipment. [Display omitted] •The FeCoCrNiMo HEA cladding layers were fabricated on Q235 steel using plasma cladding techniques.•The σ phase significantly improve microhardness and wear resistance of FeCoCrNiMo HEA coatings.•The wear mechanisms of the FeCoCrNiMo HEA cladding layer mainly include oxidative wear and abrasive wear.