Microstructural Changes During Annealing of Aluminum Alloy: Modeling

Abstract

Determination of microstructural events during heat treatment operations is an important task to obtain the desired microstructures and mechanical properties. Accordingly, during heat treatment of materials that have high stalking fault energy such as aluminum alloys, concurrent occurrence of recovery and recrystallization needs to be considered. On the other hand, the annealing processes may be performed under non-isothermal conditions in which a part of softening process is carried out during heating and/or cooling stage, particularly for the case of large-scale products. Thus, for estimation of softening fraction and microstructural events, different types of problems need to be taken into account such as the deformation analysis, the kinetics of metallurgical events, and heat conduction problem. In this entry, a combined analysis is discussed to manage the above-mentioned phenomena employing the finite element analysis together with cellular automata (CA) modeling. For this purpose, the distribution of plastic strain and the stored energy after cold rolling are determined utilizing finite element formulation, while they are considered as the initial conditions for the microstructural modeling. In the next stage, a two-dimensional CA coupled with a first-order equation is used to assess the softening rate, while a thermal finite element analysis is simultaneously employed to define temperature distribution during non-isothermal annealing. The model is then examined on softening behavior of cold-rolled AA1050 plate.