From Face‐Centered Cubic–Body‐Centered Cubic Dual Phases to Single Body‐Centered Cubic: Effect of Cr Content on the Phase Structure and Wear Mechanism of Laser‐Cladded FeCoCrNiAl High‐Entropy Alloy Coatings

The FeCoCrNiAl high‐entropy alloy powder was mixed with Cr powder at different mass fractions, and a series of coatings were fabricated by laser cladding. The effects of Cr addition on the phase composition, microstructure, microhardness, and tribological properties of the coatings were systematically investigated. The results show that the FeCoCrNiAl coating without Cr addition consists of coexisting face‐centered cubic (FCC) and body‐centered cubic (BCC) phases. With increasing Cr content, a complete phase transformation from FCC to BCC occurs, resulting in a single BCC structure. The average grain size exhibits a nonmonotonic evolution with increasing Cr content, initially increasing and subsequently decreasing, reaching 12.64 μm at 30% Cr. Correspondingly, the microhardness increases from 475.55 HV 1 to 635.12 HV 1 , mainly due to the combined effects of phase‐transformation strengthening, solid‐solution strengthening, and grain refinement. Although the wear rate initially increases, it decreases at higher Cr contents. At 30% Cr, the coating exhibits the lowest wear rate, showing a reduction of approximately 57.14%.