Gd contents, mechanical and corrosion properties of Mg-10Gd-3Y-0.5Zr alloy purified by fluxes containing GdCl3 additions

The effects of GdCl3 in flux on the loss of Gd, microstructure, mechanical and corrosion properties of Mg-10 wt.% Gd-3 wt.% Y-0.5 wt.% Zr (GW103K) alloy were investigated. The results indicate that the loss of Gd in the alloy decreased when the melts were refined by fluxes containing GdCl3 additions. Thermodynamic analysis revealed that the decline of Gibbs free energy is the main reason, which slows down the reaction rate between MgCl2 and Gd in melts. In as-cast condition, after treated with 5 wt.% GdCl3 additions, tensile yield strength, ultimate tensile strength and elongation of the alloy could reach the peak value of 201.51 MPa, 154.68 MPa and 2.56% respectively. 5 wt.% NaCl aqueous solution immersion test shows that the corrosion rate of GW103K alloy decreased to 0.437 mg cm−2 d−1 after refined by JDMJ + 5 wt.% GdCl3. However GdCl3 additions have no effects on microstructure and fracture pattern of GW103K alloy.