Microstructure and dynamic compression properties of PM Al6061/B4C composite

Abstract

Aluminum 6061 matrix composite reinforced by 35 wt% B4C particle was fabricated by power metallurgy method. Then, the as-deformed composite was tested by quasi-static (0.001 s-1) and dynamic (760-1150 s-1) compression experiments. The Johnson-Cook plasticity model was employed to model the flow behavior. The damage mechanism of composite was analyzed through the microstructure observations. The results showed that the B4C particles exhibited uniform distribution and no deleterious reaction product Al4C3 was found in the composite. Al6061/B4C composite showed high yield strength, moderate strain rate sensitivity and strain hardening under the dynamic loading, and a constitutive model under dynamic compression was established based on Johnson-Cook model, and accorded well with experimental results. The microstructure damage was dominated by particle fracture and interface debonding, and the dislocation was observed in the composite at a higher strain rate.