Effects of flux containing YCl3 on the yttrium loss, mechanical and corrosion properties of Mg–10Gd–3Y–0.5Zr alloy

New fluxes containing YCl3 were developed to refine Mg–10Gd–3Y–0.5Zr (GW103K) alloy, with the aim to suppress the loss of expensive heavy rare earth element Y, but also to improve the removal of nonmetallic inclusions. The Y loss, microstructure, mechanical and corrosion properties were investigated. It was found that the loss of Y in the alloy decreased with the increasing of YCl3 in the flux. Thermodynamic calculation indicated that the main reason could be attribute to the decline of the Gibbs free energy, which slows down the reaction rate between MgCl2 and Y. The study demonstrated that the fluxes containing 5 wt.% YCl3 additions also exhibited excellent capability of removing nonmetallic inclusions. This greatly improved the mechanical and corrosion properties of GW103K alloy.