Volume 1, Issue 1
Quenching Simulation of Aluminum Alloys Including Mechanical Properties of the Undercooled States
Age hardening is the most important heat treatment to strengthen aluminum alloys. It consists of solution annealing, quenching, and aging. During quenching, a supersaturated solid solution is formed which is necessary for the following precipitation of strengthening particles. During quenching, thermal gradients occur in components, which can generate residual stresses and distortion. The finite element method (FEM) has become a very efficient tool in understanding the complex mechanisms of thermal stresses and distortions during heat treatment. Reliable numerical simulations require accurate material properties and realistic constitutive laws. In the case of quenched aluminum alloys, material properties mean the behavior of the undercooled states depending on temperature and microstructure respectively cooling rate. The mechanical properties of these non-equilibrium microstructures are not available yet. Therefore, compression tests and also tension/compression tests of undercooled aluminum alloy EN-AW A6082 (AlSi1MgMn) were performed in a quenching and deformation dilatometer. Samples have been solution annealed and quenched in the dilatometer to varying temperatures with varying cooling rates. Immediately after quenching, deformation tests on quenching temperature have been performed. The results were implemented in the material model of the FEM-Software SYSWELD. Quenching in warm water of an extruded 6082 L-profile with different legs was simulated to understand and predict residual stress and distortion generation. Using the presented model enables to simulate this complex geometry and inhomogeneous heat transfer. The experimental results of quenched 6082 L-profiles verified the above simulations.