Interesting talk about the all-aluminum body structure What prevents its development and popularity

Incredibly, the automotive industry's research and development of all-aluminum bodywork dates back to the 1980s. Many automakers from Europe, the United States, Japan and other countries cooperated with aluminum companies in research and development, and everyone wanted to make a breakthrough in aluminum body structure, but the difficulties seemed to be more than expected. By the time 1995 rolled around, Audi was the first to achieve mass production of aluminum bodies, but it didn't last long, due to cost factors.

Today's automotive products, aluminum alloy material body application ratio is constantly improving, but have the courage to use all-aluminum alloy material to build the body is still rare. The more famous Jaguar all-aluminum body to China is also turned into a mixture of steel and aluminum, Bentley Timberland as a sky-high price of luxury cars of course is to consume all-aluminum alloy, but the body once there is an impact can not be routinely repaired, driving is not particularly tired heart it. Now the world will be the automobile industry as "energy saving and environmental protection" as the next goal, the weight of a lighter aluminum body can be lighter in exchange for lower fuel consumption, manufacturers are still in the continuous research and development in order to reduce costs. With the continuous development of aluminum alloy body technology, although the cost has been reduced, but the distance from the full promotion of popularity is still a hundred thousand miles.

All-aluminum body does not mean that the appearance of the car is all aluminum?

What we mean by "body" structure is not the outer skin parts that can be seen and touched on the exterior of the car, but rather the body-in-white, which is called the "body of white" and is similar to the skeleton of the car. Doors, glass, interior panels, and a large number of electrical appliances, suspension, etc. are all mounted and fixed to the white body to form a complete car. An all-aluminum body means that the skeleton of these metals is made of aluminum.

The concept of an all-aluminum body also means that most of the main structure of the body is made of aluminum, not to say that no other material can be present at all. And aluminum material in this is not pure aluminum, but in the form of alloy, so as to be more robust and durable. Aluminum alloy is also divided into many types, a car is also possible to apply a variety of. At present, the international rules will be different with the aluminum alloy with the composition, such as copper, manganese, silicon, magnesium, magnesium + silicon, zinc, divided into seven categories and aluminum castings (HPDC), the theory is that the higher the level of the aluminum alloy itself, the strength of the corrosion resistance and other performance indicators will be better.

Aluminum alloy body, the use of different levels of aluminum alloys will be divided into good and bad performance, of course, the cost is also different. 5-7 series of aluminum alloy materials to meet the strength requirements of the body skeleton, the general body of 6 series of T4 aluminum alloy in the coating and drying yield strength of more than 200Mpa, the traditional cold-rolled rigid plate (SPCC/DC04) in the 150-160Mpa or so. 160Mpa or so. Look at it this way, all-aluminum alloy body is not only the quality of lighter, the strength is also very secure. The body is currently the highest and even the application of the 7 series of aviation-grade aluminum, strength and energy-absorbing effect is better, often used in the front part of the longitudinal beam, of course, is also the exclusive luxury car.

Advantages of an all-aluminum body

Lightweight: An all-aluminum body is lightweight, which should probably be common knowledge. The density of traditional rigid plate is about 7.8, while the density of aluminum alloy is only about 2.7. Vehicle every 500kg aluminum alloy to replace the body steel, can make the whole vehicle quality reduced by about 40%. This brings excellent lightweight performance for the vehicle as a whole. The reduction in overall vehicle mass also allows the vehicle's overall performance to be improved, such as fuel consumption, handling, acceleration, braking distance, etc. will have better performance.

High body strength: steel plate and aluminum alloy of the same strength, the thickness ratio is 1:1.4, while the weight ratio is only 1:0.5, in other words, the aluminum alloy only needs to increase the thickness by 0.2-0.5mm in order to achieve higher strength compared to the steel plate, but the quality is still much lower than the use of steel plate.

Strong corrosion resistance: Aluminum alloy itself is not stable, there is a certain degree of oxidation, but the surface of the aluminum alloy in contact with the outside world will be the first to oxidize, and form a layer of dense oxide layer. The stability of the oxide layer is very high, and it can form a tight protective layer on the aluminum alloy itself, giving it more excellent durability.

Disadvantages of all-aluminum body: In fact, it is because of the all-aluminum body there is a problem that is difficult to overcome - "high cost". The smelting of pure aluminum and aluminum alloy processing costs are much higher than the cost of traditional steel, there is no new cost reduction breakthroughs. This is no longer a research topic within the scope of the automotive industry, but a science in the direction of metal smelting.

In fact, the all-aluminum body also brings a big trouble to repair the car. Vehicles after a collision, but also brings more time-consuming and expensive repair costs, body pits through the traditional putty spray paint to repair is limited to its minor injuries, and we can not knock the larger depressions flat. Because of the small elasticity of the aluminum alloy material, the production is in the heat process of deformation shaping, but it is difficult to secondary shaping, pits knocked will become due to the ductility of the metal and the area of the diffusion, almost impossible to repair. As the thickness of aluminum plate is thicker than steel plate, forcing repair will lead to aluminum alloy surface rise. For aluminum alloy parts damaged, can only be deformed parts of the cut, the whole replacement, which for the luxury car is simply doomed, resale time will certainly be treated as an accident car.

This article comes from the author of the automobile home car, does not represent the views of the automobile home position.