MICROSTRUCTURE AND MECHANICAL PROPERTIES OF A MAGNESIUM-ALUMINIUM-ERBIUM ALLOY

摘要

Magnesium alloys with their weight saving advantage exhibit unique application potential in the automotive and aerospace industries. Recent years have seen significant progress in the development of rare earth containing Mg alloys, as rare earth addition is considered a promising route to enhance the mechanical characteristics of Mg. In the present study, a new Mg alloy containing 5.16 at. % aluminum and trace (0.05 at. %) erbium was synthesized using the disintegrated melt deposition technique followed by hot extrusion. The microstructural and mechanical properties of the developed Mg-Al-Er alloy were evaluated in comparison to that of pure Mg. Microstructural investigation revealed significant grain refinement and the presence of Mg_(17)Al_(12) intermetallic phases. Evaluation of mechanical properties under indentation loads showed significant improvement in microhardness by +50%. Under tensile loads, the developed Mg-Al-Er alloy exhibited +86%, +115% and +95% enhancement in yield strength, ultimate strength and ductility respectively. Similarly, an enhancement in yield strength by +115%, ultimate strength by +37% and ductility by +25% were observed under compressive loads. The overall effects of Al and Er addition on the mechanical properties of the Mg are discussed using structure-property relationship.