In the past 20 years, the global energy problem has become more and more serious, which makes reducing the weight of automobiles and reducing fuel consumption the key to improving the competitiveness of major automobile manufacturers. According to relevant data, for every 50kg reduction in vehicle weight, the distance traveled per liter of fuel can increase by 2km; for every 1% reduction in vehicle weight, fuel consumption decreases by 0.6% to 1%. Aluminum has the characteristics of low density and good corrosion resistance, and the plasticity of aluminum alloy is excellent. The casting, forging, and stamping processes are all suitable, and it is the most suitable for the die casting process of automobile parts production.
From the aspects of production cost, part quality, and material utilization, aluminum alloy has become an indispensable material for automobile production. At present, the United States, Japan, and Germany are the countries that use the most aluminum alloys in automobiles, such as the German Volkswagen AudiA8, A2, Japan’s NXS and other body aluminum alloys amount to 80%. Except for the aluminum used in Shanghai Santana, FAW Audi and Jetta (all imported production lines), red flags are more common in China, about 80-100kg. Some data show that replacing the traditional steel structure with an aluminum alloy structure can reduce the mass of the car by 30% to 40%, reduce the engine by 30%, and reduce the wheel by 50%. The use of aluminum alloys is one of the important ways for automobile lightweighting, environmental protection, energy saving, speed-up and efficient transportation. Therefore, research and development of aluminum alloy cars are now very necessary.
Among lightweight metals, although the density of magnesium alloys is lower than that of aluminum alloys, the cost of magnesium ingots is higher, and there are many technical obstacles in the part manufacturing process, such as the lack of high-temperature die-casting alloys and design data, poor surface treatment technology, and low level of combination Therefore, the current amount of use in automobiles is quite limited; although titanium alloys for aerospace have high mechanical strength, difficult manufacturing processes and expensive manufacturing costs, titanium alloys cannot be applied to automobile production in large quantities. Aluminum alloy has good comprehensive performance in terms of cost, manufacturing technology, mechanical properties, and sustainable development (the crust has the largest aluminum content, accounting for 8.1%). Therefore, aluminum alloy is the light metal material of choice in the automotive industry now and in the future.
The application of alloys in automobiles not only has obvious weight reduction and energy saving effects, but also meets the development trend of safety and environmental protection and automotive materials, and has significant economic and social benefits. Because the weight of the car body plays an important role in the whole vehicle, the development of high-performance and distinctive car body panels is an important link in the process of China’s automobile lightweight.
Aluminum alloy materials have the following advantages:
- Conform to the world’s environmental protection concepts. The improvement and progress of smelting technology will continue to increase productivity, so the unit price of aluminum alloys will continue to decline, and the environmental protection concepts of governments and people around the world will gradually increase. Therefore, auto manufacturers will be strongly required to adopt technology and cost changes. More aluminum alloy.
- Aluminum alloy is easy to improve stamping and forming ability. Aiming at the problem of low stamping performance of aluminum alloy sheets, on the one hand, through the study of materials science, the proportion of alloying elements in each alloy can be reasonably optimized, and the overall performance of the alloy can be improved through reasonable proportions and interactions among the elements. On the one hand, processes such as heat treatment process and rolling process can be improved to improve the stamping and forming ability of aluminum alloy plates.
- The effect of weight reduction and energy saving is obvious. Aluminum has good mechanical properties, its density is only 1/3 of that of steel, it has good thermal conductivity, second only to copper, its machining performance is 4.5 times higher than iron, and its naturally formed oxide film has good corrosion resistance. Therefore, aluminum has become the most ideal material for automobile lightweight.
- Passenger comfort and safety have been improved. Aluminum alloy cars reduce the weight of the car without reducing the capacity of the car, reduce the center of gravity of the car body, and make the car more stable and comfortable. Due to the good energy absorption of aluminum, it has obvious advantages in terms of collision safety. The deformation area at the front of the car will generate wrinkles during a collision, which can absorb a large amount of impact force, thereby protecting the driver and passengers behind.
- aluminum is easy to recycle. During the use of aluminum products, there is almost no corrosion or only slight corrosion. Among the conventional materials used in industry, the recovery rate of aluminum is the highest. During the cycle of aluminum material—aluminum products—recycled aluminum ingots—reprocessed into aluminum, the loss of aluminum is also only about 5%, and its recycling performance is higher than that of any commonly used metal.