BEIJING--July 12, 2012: As the demand for lightweight vehicles expands, aluminum has become the best alternative material for automobile construction due to its good mechanical property, processability, corrosion-resistance and weldability. With a density only one third of that of steel, the aluminum body of a passenger vehicle weighs 46% less than a traditional steel one, which also improves safety and fuel efficiency.
Stable growth of demand in the automobile market lays a solid foundation for aluminum application.
In 2011, the growth rate of China's automobile sales volume shrank dramatically to 2.45% only, partly due to the state's suspension of auto consumption incentive policies. However, the factors driving the growth of China's automobile market remained unchanged. The progress of urbanization and the upgrade of the consumption structure will continue to boost the automobile consumption. It is estimated that China's automobile market will keep a stable growth from 2012 to 2015, with a compound annual growth rate of 8.1%. The sales volume is expected to reach 25.287 million by 2015.
Forecast on China's Auto Sales Volume and Growth Rate
Source: China Association of Automobile Manufacturers & CCID Consulting
Specifically, aluminum sheets for automobile body will be the most promising sector. Currently among all aluminum parts used in automobile construction, including castings, forgings, section bars and sheets, castings take up the biggest share. Aluminum has been used in automobile body, mainly for engine cabin covers, doors and trunk lids, in Europe, North America, Japan and South Korea, represented by Audi's A8 and A2, Chrysler's Prowler and Jeep, Subaru's Legacy and Hyundai's Motors Genesis. However, China has seen a slow growth of aluminum application in automobile due to technical bottlenecks. Once technical breakthroughs are achieved, massive application of aluminum sheets in automobile construction can be expected. CCID Consulting estimates that the passenger vehicle market will need at least 1.802 million tons of aluminum sheets annually, assuming that aluminum replaces 15% of the steel used in automobile manufacturing by 2015. Even if aluminum only replaces 5% of the steel, the demand will still be as large as 601,000 tons.
The key is to improve aluminum sheets' performance and make breakthroughs in application technologies.
As a result of the technical bottlenecks concerning aluminum sheets' performance and application, the domestic automobile manufacturers are facing high costs of aluminum application and are reluctant to use aluminum sheets. Meanwhile, as foreign-owned aluminum enterprises like Novelis have geared up for the Chinese market, the domestic research institutes, aluminum companies and automobile manufacturers will have to unite and accelerate the R&D process to make technical breakthroughs in the two aspects.
Aluminum alloys currently used in automobile body include Al-Cu-Mg (2000 series), Al-Mg (5000 series) and Al-Mg-Si (6000 series). The 5000-series alloys boast low cost and good shaping property, but they will leave traces of tensile strain after being shaped and need re-polishing with abrasive materials. In response to this, aluminum materials suppliers have developed the 6000-series alloys, which are preferred by automobile manufacturers for their better performance in extension, stretching and anti-pit ability. However, being thick and expensive, aluminum alloy sheets currently found in the Chinese market still cannot meet the requirements of the automobile manufacturers.
Regarding the application technologies, including preprocessing, thermal treatment, shaping, soldering, spray finishing and baking, the key is to have the aluminum companies and automobile manufacturers conduct R&D cooperation and develop such techniques as spray finishing and selection of paint colors. In addition, automobile manufacturers also need to purchase required devices such as soldering devices if they decide to use aluminum sheets.