Two types of 50vol%B4Cp/2024Al composites with the particle size of 25 μm and 50 μm were prepared by squeeze casting. The density

hardness

flexural strength

quasi-static compressive strength

KIC of composites was tested

and the dynamic compressive strength under high strain rate load was examined by Split Hopkinson Pressure Bar system. The results show that: The density of 50vol%B4Cp/2024Al composite is 2.7 g/cm3

and the hardness is 60 HRA; When the size of B4C particles is 25 μm

the composite’s flexural strength is 527 MPa

KIC is 13.56 MPa·m1/2 and the quasi-static compressive strength is 797.5 MPa

distinctly higher than that of the composite with particle size of 50μm. In addition

the dynamic compressive strength of fine-particle reinforced composite is relatively higher than that coarse-particle reinforced one. Strain dependent damage evolution leads to the strain softening

and rate dependent damage evolution caused the insensibility of strain rate or even negative strain rate effect.