Microstructure of WTaNbMo refractory high entropy alloy coating fabricated by dynamic magnetic field assisted laser cladding process

Abstract

WTaNbMo refractory high entropy alloy (RHEA) coatings were prepared by laser cladding assisted with reciprocating dynamic magnetic field on Inconel 718 substrates. The effects of dynamic magnetic field on the microstructure, defects and residual stress were discussed. The results show that the reciprocating magnetic field improves the microstructure homogeneity of the laser cladded WTaNbMo coating. The coatings are composed of WTaNbMo solid solution (BCC) and γ-(Ni, M). With reciprocating magnetic field assistance, the flow in the molten pool is accelerated, porosity is reduced. The residual stress inside the coating is depressed, thereby cracks in the coating are inhibited. The flow behavior in the molten pools was also discussed.