Since 1990, the application of magnesium in automobiles has been increasing at a relatively rapid rate. The "magnesium" used in automobiles has developed rapidly at an average annual growth rate of 20%. Magnesium alloys have become an important field in the development of automobile material technology.
1. Application advantages of magnesium alloys in automobiles
Compared with other metals, magnesium alloy has many performance characteristics:
①The density is small. For example, the density of AZ91 magnesium alloy is 1.81g·cm-3, which is about 2/3 of aluminum and 1/4 of steel, which is close to the density of engineering plastics.
②Tensile strength, yield strength and elongation are equivalent to aluminum alloy castings.
③It has good electromagnetic shielding performance, anti-radiation performance, high-precision machining, and good thermal conductivity. Used on die-cast automobile wheels, it can effectively dissipate braking friction heat and improve braking stability;
④It has good die-casting performance and dimensional stability, and the minimum wall thickness of die-casting parts can reach 0.15 mm, which is suitable for manufacturing all kinds of automobile die-casting parts;
⑤Has a good damping coefficient, the shock absorption performance is better than aluminum alloy and cast iron, used in the shell can reduce noise, used in the seat, rim can reduce vibration, and improve the safety and comfort of the car;
⑥Easy to recycle and regenerate. The recovered magnesium alloy can be directly melted and then cast without reducing its mechanical properties.
Relevant research conclusions: for every 100kg reduction in vehicle quality, the fuel consumption per 100 kilometers can be reduced by 0.7L, and the vehicle's own weight can be reduced by 10%, and the fuel efficiency can be improved by 5.5%. The increasingly serious energy crisis and increasingly stringent environmental protection laws and regulations have led to rising demands for weight reduction and energy conservation in modern automobiles. Lightweight has become the main development direction of automobile material selection. Magnesium alloy has become a lightweight material for automobiles, and its development and application have attracted the attention of all countries.
2. Magnesium alloy die castings that have been used in automobiles
With the in-depth implementation of the "Magnesium Alloy Application Development and Industrialization" project, the automobile industry has benefited a lot from this project, with obvious effects, and many companies have made considerable progress. The Auto parts aluminum die casting that have been developed and applied are as follows:
Interior components: instrument panel, seat frame, steering wheel, steering column, steering column bracket, seat lifter, control platform, airbag cover, lock device cover, radio shell, small tool box door, window motor cover, Brake and clutch pedal bracket, pneumatic bracket pedal, etc.
Car body components: door frames, tail panels, roof frames, roof panels, IP beams, etc.
Engine and transmission system: valve cover, cam cover, four-wheel drive transmission body, manual shift transmission, clutch housing piston, intake pipe, oil pan, AC motor bracket, transmission housing, gear box housing, oil filter connector , Motor cover, cylinder head cover, distribution plate bracket, oil pump housing, fuel tank, oil filter bracket, left half crankcase, right half crankcase, empty hood, left exhaust pipe, right exhaust pipe, etc.
Chassis: wheels, engine brackets, front and rear booms, tail plate brackets.