Forming Limit Evaluation for AA5182 Aluminum Alloy at Warm Temperatures Based on M–K Model

The M–K method is used to predict the forming limit of AA5182 aluminum alloy to study the effect of temperature, strain rate sensitivity index and strain hardening exponent. Three kinds of yield criterion Yld2000, Barlat’s 1989 and Hill’s 1948 are introduced into the model, respectively, to find which one is most suitable for predicting the forming limit of AA5182 at different temperatures. The forming limit experiment of AA5182 aluminum alloy under different temperatures is carried out to verify the accuracy of the prediction. As results show that both Barlat’s 1989 and Yld2000 can get the ideal prediction results for the forming limit of AA5182. However, since Barlat’s 1989 can be implemented with fewer parameters, it is considered to be more convenient and suitable for predicting forming limit of AA5182 than the other two yield criteria. Then, influence of parameters in the flow stress model is analyzed. It indicates that strain rate sensitivity index has great influence on the material forming limit and the effect of strain hardening exponent is negligible.