Die Casting Material: Introduction of Magnesium Alloy
Magnesium alloys are alloys based on magnesium and added to other elements. The main alloying elements are aluminum, zinc, manganese, cerium, lanthanum and a small amount of zirconium or cadmium. Currently the most widely used is magnesium-aluminum alloy, followed by magnesium-manganese alloy and magnesium-zinc-zirconium alloy.
Characteristics:
1. Light weight, high specific stiffness and specific strength
The density of magnesium alloy is 1.74g/cm 3 , which is only equivalent to 25% of cast iron and about 64% of aluminum alloy. It is the lightest material among the commonly used metals.
Although the specific gravity of magnesium alloy is heavier than plastic, the strength and modulus of elasticity per unit weight are higher than that of plastic. Therefore, in the case of the same strength parts, the parts of magnesium alloy can be made thinner and lighter than plastic. In addition, since the specific strength of the magnesium alloy is also higher than that of the aluminum alloy and the iron, the weight of the aluminum or iron component can be reduced without reducing the strength of the component.
Therefore, magnesium alloys are widely used in portable devices and the automotive industry to achieve lightweighting.
2. Strong thermal conductivity
Although the thermal conductivity of magnesium alloys is not as good as that of aluminum alloys, it is several times higher than that of plastics. Therefore, magnesium alloys are used in electrical products to effectively dissipate internal heat to the outside of the casing.
For example, magnesium alloy is used on the outer casing and heat dissipating components of computers and projectors that generate high temperatures inside, and the use of magnesium alloy on the outer casing of the television can achieve no heat dissipation holes.
3. Excellent electromagnetic wave shielding performance
The electromagnetic wave shielding performance of the magnesium alloy is better than that of the plating film on the plastic. Therefore, the use of the magnesium alloy can eliminate the electroplating process of the electromagnetic wave shielding film.
4. Good impact resistance and compression resistance
Compared with other metals, magnesium alloy has high deformation resistance and good absorption of vibration energy. After impact, it can absorb impact energy without breaking.
Therefore, a magnesium alloy is used for parts in the vicinity of the vibration source of the hard disk drive reading device or the like, and a magnesium alloy is used on the fan blades to reduce vibration and achieve low noise. In addition, magnesium alloys are used on the steering wheel and the seat in order to increase the impact absorption and weight reduction after the automobile is impacted.
The following table: Comparison of physical properties of various materials
