Dynamic compressive behavior of Si₃N₄ p/Al composites

Dynamic compressive behavior of Si₃ N₄ p/Al composite with 34. 4%, 46. 3% and 51. 41% of Si₃ N₄ p ceramic content in volumetric fraction prepared by pressure-free infiltration technology was examined by the Split Hopkinson Pressure Bar apparatus with different strain rate and was compared with that of ones in quasi-static state to analyze effects of strain rate and ceramic content as well as microstructure. The results reveal that dynamic compressive strength of Si₃ N₄p/Al composites is higher than quasi-static strength. Dynamic compressive response of the composites is characterized by the interaction of strain rate strengthening with hot softening, which is attributed to high strain rate loading resulting in high dislocation accumulation rate of aluminum matrix in the composites and high temperature-increment. Dynamic compressive strength of the composites is increased with increasing in the ceramic content, while hot softening is declined with increasing in the ceramic conte and decreasing in the strain rate of aluminum matrix.