Abstract:Deformation behaviors of CNTs/Al alloy composite fabricated by the method of flake powder metallurgy were investigated by hot compression tests, which were performed in the temperature range of 300-550 °C and strain rate range of 0.001- 10 s^-1 with Gleeble-3500 thermal simulator system. Processing maps of the CNTs/Al alloy at different strains were calculated to study the optimum processing domain. Microstructures before and after hot compressions were characterized by electron backscattered diffraction (EBSD) method. Stress-strain curves indicate that the flow stress increases with the increase of strain rate and the decrease of temperature. The processing maps of the CNTs/Al alloy at different strains show that the optimum processing domain is 500-550 °C, 10 s^-1 for hot working. EBSD analysis demonstrates that fully dynamic recrystallization occurs in the optimum processing domain (high strainrate 10 s^-1), whereas the main soften mechanism is dynamic recovery at low strain rate (0.001 s ^-1).

Key words: CNTs/Al alloy composite; flake powder metallurgy; recrystallization; processing map; flow stress