Magnesium alloy after solid solution treatment without artificial aging can increase the tensile strength and elongation, and obtain the maximum toughness and impact resistance. Due to slow diffusion of alloy magnesium alloy elements, and therefore requires a longer heating time to ensure the full solid solution strengthening phase. Magnesium alloy sand thick walled casting solution for the longest time. The second is thin-walled castings or metal mold casting, magnesium alloy is the shortest. The diffusion of alloy elements and phase decomposition process is slow, so the quench sensitivity of magnesium alloy low, quenching without rapid cooling, cooling airflow in the still air or forced flow in the artificial. But the vast majority of magnesium alloy is not sensitive to the natural aging, after quenching can keep at room temperature solid state for a long time.