Aluminum alloys and the thermal processing associated with automotive sheet

This paper considers the different processing issues involved for automotive sheet in the 5000 and 6000 series alloys, with the non-heat treatable alloys being batch annealed to provide O-temper sheet while the 6000 series alloys are solutionised on a continuous heat treat Line to provide T4 properties. After fabrication to the final form the material is subjected to a painting cycle, involving recovery and precipitation reactions which determine the final properties. The paper considers how the paint bake cycle can be modelled to predict the properties in the final part. By appropriate use of mechanical and thermal models it is possible to estimate the properties of the sheet in service.