Fabrication of FeCoCrNiMnAl0.5-FeCoCrNiMnAl gradient HEA coating by laser cladding technique

Abstract

In this study, an FeCoCrNiMnAl 0.5 -FeCoCrNiMnAl gradient high-entropy alloy (HEA) coating was fabricated by laser cladding. The gradient HEA coating was subjected to compression at 600 °C, and the phase structure, grain orientation, recrystallization state, grain boundary distribution, dislocation content and plastic deformation resistance of the coating were systematically studied by EBSD technology. The gradient HEA coating had a compression strength of 504 MPa with an elongation of 82% at 600 °C, and the surface of the FeCoCrNiMnAl cladding layer exhibited no obvious cracks. The gradient HEA coating exhibited an excellent balance between strength and toughness. The FeCoCrNiMnAl cladding layer formed a fiber texture parallel to the compression direction, and its body-centered cubic (BCC) structure had a high stacking fault energy and more continuous dynamic recrystallization. The FeCoCrNiMnAl 0.5 cladding layer formed a slab texture perpendicular to the compression direction, and this cladding layer with a face-centered cubic (FCC) structure had low stacking fault energy, which formed deformed grains that stored many dislocations. The FeCoCrNiMnAl 0.5 cladding layer reduced the energy of the FeCoCrNiMnAl cladding layer by storing dislocations, and its cracking tendency during high temperature compression was decreased, thereby extending the service life of the coating surface. • The FeCoCrNiMnAl 0.5 -FeCoCrNiMnAl gradient HEA coating was prepared by laser cladding. • FCC phase in the FeCoCrNiMnAl 0.5 cladding layer had low stacking-fault energy and high dislocation storage capacity. • Cracking tendency of the FeCoCrNiMnAl cladding layer was effectively reduced. • The gradient HEA coating achieved an effective strength-toughness balance.