Novel Ultrafine-Grain Mg-Gd/Nd-Y-Ca Alloys with an Increased Ignition Temperature

Two novel ignition-resistant magnesium alloys, Mg-2Gd-2Y-1Ca and Mg-2Nd-1Y-1Ca, were prepared in the ultrafine-grain condition by equal channel angular pressing (ECAP). In addition, four commercial alloys-AZ31, AX41, AE42 and WE43-were prepared similarly as a reference. The microstructure, mechanical properties and ignition temperature were thoroughly investigated. Both novel alloys exhibited a mean grain size of similar to 1 mu m and dense distribution of small secondary phase particles. The mechanical strength measured by the tensile deformation test showed that the novel alloys are much stronger (similar to 290 MPa) than all commercial alloys except WE43. However, Ca segregation into the grain boundaries caused a significant decrease in ductility (<6%). The ignition temperature of the novel alloys (similar to 950 degrees C) was considerably improved by the presence of Gd/Nd, Y and Ca. This study showed that both novel alloys exhibit high strength and high ignition temperature in the ultrafine-grain condition.

Automated summary

Two novel ignition-resistant magnesium alloys, Mg-2Gd-2Y-1Ca and Mg-2Nd-1Y-1Ca, were prepared by ECAP and compared with four commercial alloys. The novel alloys exhibited a mean grain size of around 1μm and a dense distribution of small secondary phase particles. Mechanical testing showed that the novel alloys had significantly higher strength than the commercial alloys (except WE43), but lower ductility due to Ca segregation. The ignition temperature of the novel alloys was considerably improved (around 950°C) by the presence of Gd/Nd, Y and Ca. This study demonstrated the high strength and high ignition temperature of the novel alloys in the ultrafine-grain condition.