THE ROLE OF AS-CAST POROSITY, STRESS AND STRAIN ON HOT TEARING IN DIRECT CHILL CAST AA5182

摘要

This paper presents a review of two recent publications describing comprehensive mathematical and experimental studies on the subject of hot tearing and aluminum alloys-one which predicts hot tearing in DC cast aluminum extrusion billets and the second which examines hot tearing in rolling ingots- and identifies areas for improvement. The paper goes on to present summaries of two experimental studies focused on understanding mechanistically how hot tears form in aluminum alloys. Finally, a method for quantifying semi-solid deformation behaviour based on a virtual material model will be presented. The data generated using the model has been described together with its use to formulate an empirical relationship to account for the effects of fraction solid, grain size and volume fraction porosity on the stress- strain response of semi-solid AA5182. To conclude, it is proposed that incorporation of such a model could significantly improve the predictive capabilities of thermal-stress process models.