Work-hardening characteristics of aluminium under hot-working conditions

The stress-strain behaviour of aluminium 99.94% purity is described satisfactorily in a rational manner by combining the exponential-saturation equation earlier proposed by Voce with two different models advanced to correlate steady-state now stress data with temperature and strain rate: The Rocks model (model 1) and the Sellars-Tegart-Garofalo (STG) model (model 2). These models are extended to correlate also the finite yield stress at the onset of plastic deformation. The optimization of the flow stress parameters is carried out by means of the Newton-Gauss method which provides a satisfactory solution in few iterations.