Simulation of Microporosity in Gravity Die Cast Al-Si Foundry Alloys

摘要

A combined experimental and numerical approach to the analysis of microporosity formation in an A356rnalloy cast in a step mould is presented. A model for porosity formation and growth based on microscale gas diffusion!rntransport in the melt, coupled with a model for feeding flows and pressures during solidification, has shown good agreementrnwith available experimentally measured porosity distributions for directionally solidified samples. In this work, the application ofrnthis modelling approach for gravity shape castings is investigated. Careful casting experiments with controlled hydrogenrnlevels were designed and carried out. The reproducibility of these experiments was assessed by performing two experimentsrnunder identical conditions on two different days. The experimental results were compared with the predicted porosity levels.rnThe results show good agreement between measured and simulated porosity profiles for a 0.2 mL/100 g melt hydrogenrncontent The experimental validation carried out is essential for assisting and further development of the modelling tools.