Mathematical and Experimental Study on Hot Tearing of AA5182 Aluminum Alloy

Hot tearing is a severe defect in the casting process. One common method used for predicting the hot tearing susceptibility for an alloy is the RDG (Rappaz–Drezet–Gremaud) criterion. The RDG criterion was improved by including all strains in three different directions, and a mathematical model was built to improve the accuracy in predicting hot tearing. Prediction results were compared with experimental results and those of several other commonly used criteria, such as stress-based, Niyama, and Clyne and Davies criteria. Results showed that the improved RDG criterion presents optimal prediction accuracy. The prediction results of the improved RDG criterion are consistent with the experimental results. Furthermore, the improved RDG criterion was used to investigate the influence of casting conditions on hot tearing susceptibility. It is found that selecting suitable casting and mold preheating temperatures is necessary to reduce the susceptibility to hot tearing.