Nickel improves glass-forming ability of mischmetal substituted yttrium in the Mg–Cu based alloys

•Effect of chemical changes on the GFA of Mg65Cu25Y10 metallic glass is studied.•Yttrium is replaced by cheaper Ce75La25 mischmetal.•Effects of Ni substitution over Cu are investigated.•Appropriate copper substitution leads to acceptable supercooled liquid region.

The substitution of Y by mischmetal was investigated on the Mg65Cu25Y10 metallic glass, in order to reduce pure rare earth content and improve manufacturing for potential applications. Works showed that this substitution is well accommodated by partial substitution of Cu by Ni. Alloys were prepared by planar flow melt spinning, with various amounts of mischmetal (0, 5 or 10 at.%) and Ni (0, 5, 12.5, 20 or 25 at.%). With increasing content of mischmetal and nickel, the glass forming ability, especially the width of the supercooled liquid region tends to decrease. However, an optimal substitution of Cu by Ni (12.5 at.%) in an alloy free from Y has been identified to present an appreciable glass forming ability with a supercooled liquid region of 35 K.