Microstructure and tensile properties of sand cast and die cast AE44 magnesium alloy

The AE44 magnesium alloy was prepared by gravity and die casting methods. The microstructure and mechanical properties were investigated. The results demonstrated that microstructure of sand casting consist of large grains of α solid solution and needle-shaped Al ₁₁RE ₃ phase, globular particles of Al ₁₀RE ₂Mn ₇ and small volume fraction of Al ₂RE. Die casting process caused significant refinement of structure and change of phase composition. Die cast AE44 alloy consists of Al ₁₁RE ₃ phase and precipitates of A1 ₂RE and Al _2.12RE _0.88 compounds. The mechanical properties at room and elevated temperature of the sand cast alloy are relatively low due to coarse-grain structure. Die-casting process increases the ultimate tensile strength, yield strength and elongation of AE44 magnesium alloy.