Effect of Al addition to Rapidly Solidified Mg-Cu-Rare Earth Alloys

Abstract

Rapidly solidified Mg based alloys are of interest for industrial applications as a structural material and for hydrogen storage. Mg-Cu-Rare Earth alloys have shown high glass forming ability; full amorphous structure with thickness of mm size can be obtained within these systems. However, their brittle behavior limits their industrial applications. In the present work, the Al effect in substitution of Cu in the Mg 65 Cu 25 MM 10 (at%, MM: mischmetal) was studied. Samples up to 15at% Al were prepared by splat cooling and their microstructure, stability and mechanical properties were characterised. The crystallization temperature increases with the Al addition; the amorphous phase with different Al content has a Young's modulus of ~55GPa; the microhardness increases with the Al content in the amorphous and crystallized samples and the fracture of the alloy containing 10at% Al showed ductile vein patterns characteristics of ductile metallic glasses. The partial Cu substitution by Al can improve the stability and mechanical properties of the amorphous Mg 65 Cu 25 MM 10 alloy.

Quantitative microstructure study of melt-spun Mg65Cu25Y10

“…4 and were analyzed, namely, T g and T x were detected and the enthalpy variation during the crystallization was calculated by integrating the curve in the vicinity of the crystallization peak. The values of T g , T x and the enthalpy variations during the crystallization and melting processes Comparing the crystallization behavior observed in the current study with some other DSC studies reported over the last few years [4,[25][26][27] it comes that the current study is in line with some of the reported results of other researchers. The value of T x for the as-cast material, as can be seen from Table 1, is 179.4 °C and the value of ΔT x obtained is 41.4 °C.…”

“…Although studying a different composition, they noted the appearance and growth Mg 2 Cu phase accompanying the crystallization process, the first stage of which started at 178 °C, and the second one started at 220 °C, the existence of Mg 2 Cu phase is well supported by the current study. Rozenberg et al [27] studied rapidly solidified Mg-Cu-RE alloys, they pointed at the positive role of Y on the GFA of such alloys and found that for the Mg 65 Cu 25 Y 10 alloy, T x was 184 °C and T g was 152 °C so that ΔT x was found to be 32 °C.…”