Heat Treatment Simulation of Aluminum Alloy Wheels and Investigation of Process Steps

Abstract

T6 heat treatment is usually applied to Al-Si-Mg alloy parts. This process can be modeled and solved by computer simulations for reduced experimental costs and environmental effects, and more flexible design approaches because this approach can avoid a high number of experiments based on trial and error. In the first stage, microstructural and mechanical characterization studies were performed for three different conditions: as-cast, quenched and artificially aged. Also, according to the 3D scanner test results, dimensional change of three different regions was observed at all of the heat treatment steps. In the second part, the production steps of the aluminum alloy wheels were simulated for further evaluation of the heat treatment by analyzing yield strength, residual stress state and dimensional changes on the different regions of the alloy wheel’s cross section. Yield strength predictions obtained by modeling based on quench factor analysis and Shercliff–Ashby can be considered compatible with the experimental yield strength values. Although the error percentage between predicted and measured values is less than %10 in outer and inner flange regions, a more significant error value is present for the spoke region. As quench factor analysis values increased, the measured hardness values also tended to increase. Compressive residual stress is mostly observed on the wheel surface after quenching, and a slight but insufficient stress relief was observed in the artificial aging step. The dimensional change obtained by simulation is highest in the outer flange region after quenching and dimensional change increased in all regions after the artificial aging.