Flow stress of an aluminium alloy in the warm working range

The effect of temperature and processing history on the flow stress of a two-phase aluminium (Al-6% Cu) alloy was investigated. The flow stress was determined from the changes in dimensions of flat, ring-shaped specimens using Avitzur’s upper bound theorem. The results indicate that the flow stress increases with the degree of deformation irrespective of the specimen history considered and this tendency is in general more pronounced at large deformations. The flow stress of this alloy at large deformation is considerably lower at 573 K than at the lower temperatures tested. The morphology and distribution of the second phase particles of this alloy changed considerably depending upon the processing history, temperature and deformation.