The disadvantages of magnesium alloy plate:
1. Flammability
Magnesium has a great affinity with oxygen, and it is easy to react with oxygen in the air at high temperature or even in a solid state, releasing a lot of heat, and the generated magnesium oxide thermal conductivity is not good, the heat can not be dispersed in time, and then promote the oxidation reaction further, forming a vicious cycle, and magnesium oxide is loose and porous, Can not effectively block the invasion of oxygen in the air.
2. Poor plasticity at room temperature
Magnesium is a densely packed hexagonal crystal structure with only one slip plane and three slip systems at room temperature, so its plastic deformation mainly depends on the coordination of slip and twinning. However, slip in magnesium crystals only occurs in some crystals where the slip plane is inclined to the direction of tension, so the process of slip will be greatly limited, and twinning is difficult to occur under this direction. So the crystal is brittle and breaks very quickly. When the temperature exceeds 250C, the additional slip plane in magnesium crystal begins to take effect, and the plastic deformation ability becomes stronger.
3. Poor corrosion resistance
Magnesium has very high chemical activity, its equilibrium potential is very low, and it is easy to have galvanic corrosion when it comes into contact with different metals, and it acts as an anode. At room temperature, magnesium surface reacts with oxygen in the air to form magnesium oxide thin film. However, due to the loose magnesium oxide thin film, its density coefficient is only 0.79, that is, the volume of magnesium oxide generated after magnesium oxidation shrinks, so the corrosion resistance is poor.
Advantages of magnesium alloy plate:
4. Magnesium alloy has low heat capacity, fast solidification speed and good die-casting performance.
5. Magnesium alloy has good toughness and strong shock absorption. The magnesium alloy is prone to large deformation under external force. But when the impact load, absorbed energy is 1.5 times of aluminum, therefore, very suitable for the impact of the parts - wheels; Magnesium alloy has high damping capacity and is an ideal material to avoid workers fatigue caused by vibration and noise.
6. Magnesium alloy has excellent machinability. Magnesium alloys are easy to work among all the commonly used metals. Machining can use high cutting speed and cheap cutting tools, low tool consumption. And without grinding and polishing, you can get a very smooth surface with cutting fluid.