Thermal stability, mechanical properties and corrosion behavior of a Mg–Cu–Ag–Gd metallic glass with Nd addition

By the minor addition of Nb to a Mg–Cu–Ag–Gd alloy, a Mg–Cu–Ag–Gd–Nb bulk metallic glass (BMG) with improved thermal stability and corrosion resistance as well as good mechanical properties was developed. Mg₅₄Cu_26.5Ag_8.5Gd_11−xNb_x (x = 0, 1) BMGs with a diameter of 2 mm were fabricated by copper-mold casting. The Mg₅₄Cu_26.5Ag_8.5Gd₁₀Nb₁ BMG exhibits enlarged supercooled liquid region of 58 K. Electrochemical measurements indicate that the addition of Nb improves the corrosion resistance of the Mg-based BMG in NaCl solution evidenced by the increased corrosion potential, though no significant effect of Nb on the corrosion behavior of the BMG in NaOH solution is observed. The Mg–Cu–Ag–Gd–Nb BMG also shows high compressive strength up to 890 MPa and elastic strain of about 1.9%.