Unexpected high-temperature brittleness of a Mg-Gd-Y-Ag alloy

Rare earth (RE) can produce excellent precipitation hardening in Mg alloys. However, when forming a solid solution, it also deteriorates formability, a problem that can usually be overcome by raising deformation temperature. Here we report an unexpected observation of high temperature brittleness in a Mg-Gd-Y-Ag alloy. As the temperature reached 500 degrees C, the formability decreased drastically, leading to severe intergranular fracture under only 0.5% strain. This was caused by failure of grain boundaries, which are weakened by segregated interfacial compounds. (c) 2021 Chongqing University. Publishing services provided by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ) Peer review under responsibility of Chongqing University

Automated summary

In Mg-Gd-Y-Ag alloy, high temperature brittleness may occur due to weakened grain boundaries caused by segregated interfacial compounds.