Compression Deformation Flow Stress Behavior and Prediction of Pure Copper

Abstract

The deformation characteristics of pure copper have been investigated by compression tests in the temperature range of 20 °C~900 °C and strain rate range of 0.001 s-1~1 s-1. The results showed that the flow stress of pure copper increased with increasing strain rate and decreasing deformation temperature. Three types of strain-contained flow stress prediction models were developed. The flow stress prediction models based on parameters such as α, Q, lnA and n were related to deformation temperature, strain rate and strain, the prediction accuracy of the flow stress was deeply influenced by the cumulative error of multi-parameter fitting. The flow stress prediction model based on σ, , ε and T constitutive relations and the flow stress prediction model based on GA+BP possessed less correlation with microscopic deformation mechanism, proving to have high prediction accuracy, in which GA+ BP-based flow stress prediction model is in very good agreement with true stress curve, which is of significance to the guidance of hot working of pure copper.