Phase Field Simulation of the effect of Aging Precipitates on Grain Growth in Aluminum Alloys

Abstract

Aluminum alloy skin for automobile is the focus of development, application and research of aluminum alloy for automobile. At present, the problems such as aging stability, formability, concavity resistance and bake hardening of anti-baking paint need to be solved urgently. The aging precipitates of baking varnish have the effect of pinning grain boundaries and refining grains. In this study, the topological transformation law of polycrystalline evolution during normal grain growth was analyzed by continuous phase field model, and the influence of different size, morphology and volume fraction of precipitated phase particles on polycrystalline growth were simulated. By verifying the Zener relationship between the particle size of the precipitate and the limit radius of the grain, an exponential function relationship different from the growth law of the ideal spherical particle pinned polycrystals was obtained. This research has an important scientific guiding role in the aging modification design of automobile skin and in improving the service life of aluminum alloy sheets.