1. Application abroad
Volkswagen is the first automobile company to apply magnesium alloy on a large scale in automobiles. As early as the 1930s, Volkswagen began to use magnesium alloy, especially since the 1990s, Germany has been in the leading position in the field of magnesium alloy. Mercedes Benz is the first company to apply magnesium alloy pressureto automobile seat bracket, Audi is the first company to launch magnesium alloy pressure casting dashboard. In recent years, AZ91D magnesium alloy has been used in the gearbox shell of Passat, Audi A4 and Audi A6, which is 25% less than aluminum alloy parts.
During 1948-1962, the United States produced millions of magnesium alloy castings by pressure casting for automobile use [8,9]. In the past decade, Ford, GM, Chrysler and other automobile companies in the United States have been committed to the development and application of magnesium alloy automobile castings, such as bogie, clutch housing, intake pipe, clutch plate, cylinder head, seat frame, oil filter housing, etc., with obvious substitution effect, greatly promoting the development of magnesium alloy.
Japan has developed a magnesium alloy low pressure casting manufacturing device, thus, after research, a series of magnesium alloy pressure casting products have been developed successively , for example, Toyota Motor Company first manufactured magnesium alloy automobile wheel hub, steering shaft system, cam cover and other parts, at present, each Japanese Automobile Company has produced and applied a large number of magnesium alloy shell type pressure casting parts.
2. Domestic application overview
In China, casting magnesium alloy has been used for more than 30 years, but it was mainly used for shell, wheel and frame of aerospace industry [5,8] at first. It started relatively late in the automobile industry. At present, only about 100 enterprises are engaged in the production and research of magnesium alloy pressure casting parts. SAIC, FAW, Dongfeng Motor Company and Chang’an automobile have played an important role in the research and development of magnesium alloy applications in the automotive field.
In the early 1990s, SAIC was the first to apply magnesium alloy to automobiles in China. For the first time, it used magnesium alloy transmission case cover, case and clutch case on Santana car. At present, the production and application technology of magnesium alloy automobile transmission shell is very mature. The casting of magnesium alloy motor shell is being tested on the electric vehicle.
FAW has developed high-performance magnesium alloy, which can be used to manufacture automobile power system components under high temperature load. It has also successfully developed magnesium alloy pressure casting parts such as foot pedal, cylinder cover, supercharger shell, steering wheel, transmission case cover, and has been applied to production.
Dongfeng Automobile Co., Ltd. has developed a complete set of technology of magnesium alloy cold chamber pressureto produce automobile parts in combination with the current situation of the equipment of the automobile parts pressure casting production enterprises in China.
Under the support of national science and technology support plan , Chang’an automobile has completed the design, analysis, mold development and manufacturing and sample production of large and complex magnesium alloy pressure casting parts, such as magnesium alloy transmission shell, oil pan and cylinder head cover. It has successfully developed the first magnesium alloy seat in China and has passed the test verification of laws and regulations, And developed magnesium alloy wheel hub by squeeze casting with Chongqing University.
3. Typical parts
At present, there are more than 100 kinds of magnesium alloy parts used in automobile, which can be divided into two categories:
a. Shell type, such as clutch shell, valve cover, valve plate, transmission shell, instrument panel, crankcase, engine front cover, cylinder box, instrument panel, filter shell, etc., which can not only reduce the weight of the whole vehicle, but also reduce the noise of the vehicle during operation due to the strong damping and attenuation ability of magnesium alloy;
b. Supports, such as steering bracket, steering wheel, lamp bracket, brake, clutch pedal bracket, brake bracket, seat frame, mirror bracket, distribution bracket and wheel hub, have good impact toughness, greatly improving the stability and safety of the car during driving.
With the development of magnesium alloy automobile parts, the application of magnesium alloy in automobile has the following characteristics , from small parts to large parts; from simple structure parts to complex parts; from simple stress parts to parts that meet special performance requirements; from component assembly to integrated design.