Microstructure and mechanical properties of AZ31 alloy ingot fabricated by semi-continuous casting

Abstract

The AZ31 alloy ingot with diameter of 110 mm and length of 3500 mm was fabricated successfully. The compositions and microstructure morphologies of the ingot at different locations were performed, which indicated that the chemical composition distributed homogeneously through the whole alloy ingot and the average grain size increased from the surface to the center. The results of the EDS and element face-scanning illustrated that the eutectic compounds mainly consisted of β-Mg₁₇Al₁₂ and a small amount of β-Mg₁₇(AlZn)₁₂. Furthermore, slight improvements of the strength and ductility were observed from the center to the surface along the axial direction of the alloy ingot, while both the strength and elongation to failure of the samples along the radial direction are higher than that along the axial direction. The fine grain strengthening was the main contributors to the strength of the as-casted AZ31 alloy.

Keywords

semi-continuous casting method / microstructure / mechanical properties / fine grain strengthening

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