In this paper the mass reduction potentials of steel and aluminum in automotive applications are compared. In order to determine the mass reduction potential of each material, several applications and concepts are analyzed. This is done by evaluation of the mass and the performance of these components. The results are computed based on theoretical mechanical fundamentals and vehicle requirements.
The analysis of a series of body structures indicates that aluminum may achieve 11 % to 34 % mass reduction depending on whether it is compared to recent optimized steel designs or to former (non-optimized) steel designs.
A hood benchmarking [3] study pointed out, that the substitution of steel by aluminum allows a mass reduction of approximately 36 %. This mass reduction goes along with a material cost increase. Aluminum is primarily used to decrease the mass. But, on the other hand, it is also possible to design steel bumpers that are up to 8 % lighter than a corresponding aluminum bumper.
The experimental analysis of front structures shows that a lower mass for this area of approximately 18 % is possible with aluminum. This finding is also associated with a higher number of parts (+18 %) and higher costs for material, forming and assembly (+59 %). It is also possible to decrease mass even more by using an optimized steel design. A mass reduction of about 22 % for a bumper rail system compared with a steel reference system is possible. With the steel solution, the number of parts is also decreased. [9]