Abnormal Effects of Temperature and Strain Rate on the Ductility of a Carbon Nanotubes Reinforced Al Alloy Composite

Carbon nanotubes reinforced aluminum alloy (CNTs/Al alloy) composite was fabricated by the method of flake powder metallurgy. With Gleeble-3500 system, hot compression tests at different temperatures and strain rates were conducted to investigate the effect of temperature and strain rate on the deformation behaviors of the CNTs/Al alloy composite. Experimental results show that the composite’s ductility is worse at higher deformation temperature within range of 300 oC-450 oC. Additionally, the composite’s ductility is better at higher strain rate, which is against general knowledge. The microstructure before and after deformation were characterized by SEM and TEM. It demonstrates that the grain size of the composite is always in the nanoscale. The abnormal effects of temperature and strain rate on the ductility may be explained by the evolution of work hardening capability at different deformation conditions.