Tailoring microstructures: A technical note on an eco-friendly approach to weight reduction through heat treatment

Abstract

The number of vehicles, globally, will approach two billion by the year 2030. The impact which these vehicles will have on world energy consumption will be substantial. In anticipation, auto companies are putting a lot of effort into reducing the weight of these vehicles. Several car manufacturers have set up lightweight structure divisions and laboratories, because the weight taken out of a car improves its performance, handling and fuel economy. Automakers are investigating many options for weight reduction, including replacing steel with other, more lightweight, materials such as aluminum or carbon fiber, or improving the design of each component. This technical note proposes a unique method of weight reduction through specialized heat treatment, while maintaining steel as the base of the body-in-white (BIW) and suspension system. The method proposed here is to evaluate the functions of the parts and the types of stress experienced at particular locations and to subsequently select the appropriate microstructure. Therefore, one part does not necessarily have one type of homogeneous microstructure, instead it has multi-microstructures. This technical note attempts to contribute to a new concept for weight reduction without the need for material substitution for lightweight constructions. Instead, it proposes an economically reasonable microstructure tailoring with heat treatment manipulation. As an example, a stabilizer bar is evaluated and a homogenization technique is suggested for computing the properties of the object.