Constitutive equations for elevated temperature flow behavior of commercial purity aluminum

In order to study the high-temperature flow stress of commercial purity aluminum (AA1070), isothermal hot compression tests were conducted at the deformation temperatures varying from 350 to 500 degrees C and strain rates ranging from 0.005 to 0.5 s(-1). The results showed that the flow stress of AA1070 was evidently affected by both the deformation temperature and strain rate. The influence of strain was also incorporated in the constitutive equation by considering the effects of strain on material constants which are consist of beta, alpha, n.A and activation energy Q. The predicted flow stress curves using the proposed constitutive equations well agree with the experimental results of the flow stress for AA1070. (C) 2012 Elsevier B.V. All rights reserved.