Encyclopedia of Magnesium Alloys

Editor: Yang Daxin Technology

Magnesium alloy is an alloy composed of magnesium as the basis and other elements added. Its characteristics are: low density (about 1.8g/cm3 magnesium alloy), high strength, large elastic modulus, good heat dissipation, good shock absorption, greater ability to withstand impact loads than aluminum alloy, and good resistance to organic matter and alkali corrosion. The main alloying elements include aluminum, zinc, manganese, cerium, thorium, and a small amount of zirconium or cadmium. The most widely used currently is magnesium aluminum alloy, followed by magnesium manganese alloy and magnesium zinc zirconium alloy. Mainly used in industrial sectors such as aviation, aerospace, transportation, chemical industry, rockets, etc. Magnesium is the lightest metal in practical applications, with a specific gravity of approximately 2/3 that of aluminum and 1/4 that of iron. It is the lightest metal among practical metals, with high strength and rigidity.

characteristic

Low density, good specific performance, good shock absorption performance, good electrical and thermal conductivity, good processability, poor corrosion resistance, easy oxidation and combustion, and poor heat resistance.

Its processing, corrosion and mechanical properties have many characteristics: fast heat dissipation, light weight, good rigidity, certain corrosion resistance and dimensional stability, impact resistance, wear resistance, good attenuation performance, and easy recycling; In addition, it has the characteristics of high thermal and electrical conductivity, non-magnetic, good shielding, and non-toxic.

Application scope: Magnesium alloys are widely used in portable equipment and the automotive industry to achieve lightweight goals.

Product Features

There are many characteristics in the processing process, corrosion and mechanical properties: fast heat dissipation, light weight, good rigidity, certain corrosion resistance and dimensional stability, impact resistance, wear resistance, good attenuation performance, and easy recycling; In addition, it has the characteristics of high thermal and electrical conductivity, non-magnetic, good shielding, and non-toxic.

Application scope: Magnesium alloys are widely used in portable equipment and the automotive industry to achieve lightweight goals

Magnesium alloy castings 1

Although the specific gravity of magnesium alloy is heavier than that of plastic, its strength and elasticity per unit weight are higher than those of plastic. Therefore, in the case of components with the same strength, magnesium alloy components can be made thinner and lighter than plastic components. In addition, due to the higher specific strength of magnesium alloys compared to aluminum alloys and iron, the weight of aluminum or iron components can be reduced without reducing their strength.

Magnesium alloy has the highest relative strength (strength to mass ratio). The specific stiffness (the ratio of stiffness to mass) is close to that of aluminum alloy and steel, and much higher than that of engineering plastics.

Within the elastic range, magnesium alloys absorb half the energy of aluminum alloy components when subjected to impact loads, thus exhibiting excellent seismic and noise reduction performance.

Magnesium alloy has a lower melting point than aluminum alloy and better die-casting performance. The tensile strength of magnesium alloy castings is comparable to that of aluminum alloy castings, generally reaching 250MPA and up to over 600 Mpa. The yield strength and elongation are not significantly different from aluminum alloys.

Magnesium alloy also has good corrosion resistance, electromagnetic shielding performance, and radiation resistance, which can achieve 100%

Magnesium alloy castings 2

Recycling and reusing.

The stability of magnesium alloy parts is higher than that of high-pressure castings, and the dimensional accuracy of the casting line is higher, which can be used for high-precision mechanical processing.

Magnesium alloy has excellent die-casting performance, with a minimum wall thickness of 0.5mm for die-casting parts. It is suitable for manufacturing various types of die-casting parts for automobiles.

But the coefficient of linear expansion of magnesium alloy is very large, reaching 25-26 μ m/m ℃, while that of aluminum alloy is 23 μ m/m ℃, brass is about 20 μ m/m ℃, structural steel is 12 μ m/m ℃, cast iron is about 10 μ m/m ℃, rocks (granite, marble, etc.) are only 5-9 μ m/m ℃, and glass is 5-11 μ m/m ℃.

Magnesium alloy is an alloy composed of magnesium as the basis and other elements added. Its characteristics are: low density, high specific strength, high elastic modulus, good shock absorption, greater ability to withstand impact loads than aluminum alloy, and good corrosion resistance. The main alloying elements include aluminum, zinc, manganese, cerium, thorium, and a small amount of zirconium or cadmium. The most widely used currently is magnesium aluminum alloy, followed by magnesium manganese alloy and magnesium zinc zirconium alloy.

Magnesium alloy has the lightest specific gravity among all structural alloys, so it can reduce the weight of aluminum or iron components without reducing their strength. The specific strength of magnesium alloy is significantly higher than that of aluminum alloy and steel, while its specific stiffness is comparable to that of aluminum alloy and steel. Within the elastic range, magnesium alloys absorb more energy than aluminum alloy components when subjected to impact loads, therefore magnesium alloys have good seismic and noise reduction performance. Under the same load, the vibration damping performance is 100 times that of aluminum and 300-500 times that of titanium alloy. Excellent electromagnetic shielding, the casing of 3C products (mobile phones and computers) should provide superior electromagnetic protection, while the magnesium alloy casing can fully absorb electromagnetic interference with frequencies exceeding 100db. Good texture, magnesium alloy has an excellent appearance and tactile texture, making the product more luxurious, and it is less prone to corrosion in the air.

The heat dissipation of magnesium alloy has an absolute advantage compared to alloys. For heat sinks made of magnesium alloy and aluminum alloy materials with the same volume and shape, the heat (temperature) produced by a certain heat source is more easily transferred from the root of the heat sink to the top by magnesium alloy, and the top is more likely to reach high temperatures. The temperature difference between the root and top of the radiator made of aluminum alloy material is smaller than that of the radiator made of magnesium alloy material. This means that the temperature difference between the air at the base and top of the heat sink made of magnesium alloy material is greater than that of the heat sink made of aluminum alloy material, thus accelerating the diffusion and convection of air inside the heat sink and improving the heat dissipation efficiency. Therefore, at the same temperature, the heat dissipation time of magnesium alloy is less than half that of aluminum alloy.

So, magnesium alloy is an ideal material for LED and other lighting fixtures, automotive application components, and other accessories that require high quality, high strength, and high toughness.