The macroscopic and microscopic mechanical behaviors of TiB

2

particle reinforced iron matrix composites were characterized by room temperature uniaxial stretching

microhardness

nanoindentation and scanning electron microscopy.The results reveal that as the volume fraction of high modulus TiB

2

particles increased from15%to 25%

the tensile strength and elastic modulus of the composites are increased from 531.0 MPa and 215.5 GPa to 659.0 MPa and 247.0 GPa

respectively

and the specific stiffness is gradually increased from 28.8 GPa·cm

-3

·g

-1

to 34.7 GPa·cm

-3

·g

-1

and the total elongation is decreased from 22.0% to 7.9%.The fracture mechanism undergoes the transition from ductile microporous aggregation to brittle transgranular cleavage

while the dominant strengthening mechanism might be fine grain strengthening and dislocation proliferation.