The flow stress curve correction and constitutive equation of 6082 aluminum alloy under thermal deformation

Thermal compression tests of 6082 aluminum alloy were carried out by using Gleeble3500 thermal simulator, and the flow stress behavior was investigated under the temperature ranging from 300℃ to 450℃ with the strain rates from 0.001 s^-1 to 1 s^-1. The material's strain constitutive equation was obtained based on the theory of friction correction and the optimization of friction correction method. The results indicate that the fluctuation of the temperature is small and has less influence on the stress when the strain rate is 1 s^-1. The stress fluctuation caused by the temperature fluctuations is less than 1 MPa. The flow strain hardening coefficient n is 5.78 and the deformation activation energy Q is 155.98 kJ·mol^-1 were evaluated by linear regression analysis. And the strain constitutive equation of the 6082 aluminum alloy during hot compression was built up. The flow stress was predicted with the maximum error less than 10%, and the average value of relative error is 1.52%.