Constitutive model for hot deformation behaviors of Al/Cu bimetal composites based on their components
(School of Mechanical Engineering, Arak University of Technology, Arak, Iran)
Abstract: The hot deformation behavior of Al/Cu bimetal composites was investigated using isothermal compression tests at temperatures of 400-500 °C and strain rates of 0.001-0.1 s-1 by considering the effects of volume fractions of composite components (30%-51% Al). In this regard, new proper constitutive equations were developed using Arrhenius-type and the rule of mixture (ROM) models. Experimental flow stress (FS) showed that processing parameters and volume fraction affect the flow behavior of composite as the volume fraction of copper has a more substantial impact on the flow behavior of the composite rods at elevated temperatures. The values of correlation coefficient (r) and average relative error of the developed Arrhenius-type constitutive equation and ROM model were 0.9826, 0.9742 and 0.9718, and also 0.18%, 1.69% and -0.84% for volume fractions of 51%, 42% and 30% Al, respectively. The results indicate that the newly developed constitutive model can successfully predict the hot working behavior of the considered bimetal composite. Finally, the microstructure of composites was investigated under different processing conditions. The dominant mechanisms for three considered volume fractions were identified at different temperatures, strains, and strain rates specified for the hot deformation of the Al/Cu composite.
Key words: Al/Cu bimetal composite; hot deformation; rule of mixture (ROM); constitutive equation; mechanical behavior; microstructure