Microstructure based modelling of Al-Mg-Si alloys in development of local heating processes for automotive structures

This work addresses the exploitation of local heating on automotive parts of age hardening aluminium alloys. Local heating can be applied for many purposes, e.g. correction of geometrical shapes, reduction of the flow stress in forming operations, and manipulation of the yield strength and the ultimate strain (i.e. local material design). One particularly promising application of local material design is in controlling the buckling behaviour during a crash situation by deliberately imposing local soft zones (i.e. thermally induced triggers). The use of an appropriate modelling tool is essential for a successful industrial implementation of such local heating processes. A finite element model with an integrated numerical model for precipitates has been developed, where constitutive equations incorporate the effect of the evolving microstructure on flow stress and work hardening. The model is applied in simulations of induction heating for creating thermally induced triggers and finally to simulate the effect of these triggers on the initial buckling performance of a crash box.