Magnesium alloy castings are characterized by light weight, good rigidity, corrosion resistance, dimensional stability, shock resistance, abrasion resistance, good attenuation property and easy recycling. In addition, they also have excellent thermal conductivity and electrical conductivity, no magnetism and good shielding property. Therefore, magnesium alloy castings are widely applied in portable apparatus and automobile industry.
Compared with plastic parts, magnesium alloy castings are heavier but have higher strength and elasticity per unit weight. Under the same strength condition, they are thinner and lighter than plastic parts. They have higher specific strength than aluminum alloy parts and iron parts. Hence, to achieve equivalent specific strength to magnesium alloy castings, weight of aluminum alloy parts and iron parts can be reduced without reducing the strength of parts, for specific strength is the ratio of strength to mass. Magnesium alloy castings have specific stiffness, namely the ratio of stiffness to density, nearly equivalent to that of aluminum and steel parts but far higher than engineering plastics.
In elastic range, on account of absorbing more energy when subject to impact load, magnesium alloy castings have better shock resistance and noise reduction performance than aluminum alloy castings. They have lower melting point than aluminum alloy castings and hence are relatively easily formed. Similar to aluminum alloy castings, they usually have 250MPA (even up to over 600MPA) of tensile strength, and yield strength and ductility. They have corrosion resistance performance, electromagnetic shielding property and radiation-proof property and can be certainly recycled and reused. They are more stable than high-pressure castings and have high dimensional precision and their wall thickness can be minimized to 0.5mm, so they are suitable for various castings for automobiles.
