A Through Process Model for Extruded AA3xxx Aluminum Alloys

The application of extruded AA3xxx aluminum tubing in automotive heat exchanger systems is a growth area. This work involves the development of a series of linked mathematical models which describe microstructure evolution as a function of processing conditions including homogenization, hot extrusion and the final brazing heat treatment. It is necessary to link the processes and track microstructure through the processes in order to predict final microstructure and properties of the aluminum in heat exchanger applications. For example, the homogenization step is critical to control the morphology, shape and spatial distribution of second phase particles, i.e. dispersoids and constituent particles. The results of i) a chemistry dependent finite difference model for homogenization, ii)a finite element based hot extrusion model and iii) a model for cold work and annealing model will be described with emphasis on the successes of the model but the challenges for future work will also be addressed.