The casting products of magnesium alloy manufacturers can be roughly divided into three stages:

(1) The first stage is a basic stage. Aluminum and zinc, that is, Mg-A1-Zn alloy, are mainly added to magnesium. Such alloys provide similar tensile strength to cast aluminum alloys. China's ZM5, Britain's L121 and the United States' AM80A belong to this type of alloy. The main additive element is aluminum, while the zinc content is low, mainly because the zinc content is prone to microscopic porosity.

(2) The second stage is a modification stage. Zirconium is added to magnesium. The common zirconium-containing alloys are Mg-Zn-Zr, Mg-RE-Zr and the like. The main role of zirconium in magnesium alloys is to refine the grain of magnesium alloy, thereby increasing the yield strength of magnesium alloy and making magnesium alloy have good fatigue resistance and low notch sensitivity. The disadvantage is still that the crystallization interval is wide, and the tendency of microscopic porosity and hot cracking tends to occur. Therefore, the most widely used is the zirconium die-cast magnesium alloy Mg-Al. In addition, in order to improve the high temperature creep resistance of the magnesium alloy, a magnesium alloy containing rare earth elements as a main component is produced.

(3) The third stage is the improvement stage. Silver is added to the magnesium alloy. After silver alloying, the aging strengthening effect can be enhanced, and the high temperature strength and creep resistance of the magnesium alloy are greatly improved, but the corrosion resistance of the alloy is lowered.