Mechanical and fracture behaviour of aluminium-based discontinuously reinforced composites at hot working temperatures

An investigation is presented on hot deformation behaviour under tensile conditions of Al 6061/20%Al2O3, Al 2618/20%Al2O3, and Al 2618/20%SiC particle reinforced composites and of an unreinforced Al 6061 reference alloy. The materials were investigated in the temperature range 350–500 C and in the strain rate range 103–101 s1. The data were numerically processed to draw workability maps for the different materials. Microstructural and fractographic analyses on deformed and on broken specimens revealed marked differences in particle damage behaviour during composite straining as a function of test temperature ad material. The overall high-temperature composite performance was thus interpreted in terms of straining and damage behaviour.