Advanced Aluminum Alloy Development and In Situ Fitness-for-Service Testing for Automotive Lightweighting

Lightweighting has led to an increased use of aluminum alloys in many automotive systems, including the powertrain, body-in-white, and suspension. Fitness-for-service certification of new alloys for these applications frequently requires development of new testing methods that would subject the test components to realistic conditions of temperature and load, while studying the long-term materials’ response. As the typical lifetime of a vehicle exceeds 3000 h, the new testing methods must provide clear indication on the material’s suitability for a target application over a more realistic timeframe. An in situ study of the creep behavior using neutron diffraction quickly reveals the response of individual crystallographic planes to the applied load under the in-service operating conditions, yielding the critical information on the expected lifetime of the targeted component. This knowledge helps to identify alloy chemistry and processing conditions that result in manufacturing components capable of sustaining the thermal mechanical loads over the expected life cycle of a vehicle. Two advanced aluminum alloys, based on Al–Si and Al–Cu systems, have been the focus of this research.