  Based on both linear and non-linear estimations of work hardening rate versus
strain curves, two mathematical models have been developed to predict the flow
curves under hot working conditions up to the peak. The models were tested for
a mechanically alloyed Al6063/0.75Al2O3/0.75Y2O3 nanocomposite under different
hot forming conditions. The predicted results from both models are found to be
in accord with the experimental flow stress curves. However, the linear model
(with an average error of 0.81%) predicted the flow stress more accurate than
the non-linear model (with an average error of 1.94%).
