WC particles reinforced steel matrix surface composites were fabricated successfully through adding proper ferro-molybdenum powder in the preformed composite layer to control interface by the vacuum full-mold infiltration casting process under negative pressure.The phase compositions

microstructure and hardness of the composite layer were characterized by optical microscope（OM）

scanning electron microscopy（SEM）

X-ray diffraction（XRD）and micro-hardness tester.The results show that

the interface structure and mechanical properties as well as the cast-infiltration effects of the composite layer are improved significantly by adding 16.67 % ferro-molybdenum powder in the preform.Meanwhile

cast-infiltration layer thickness is increased.With the volume fraction of alloy carbide increase

the composites layer hardness is nearly 2 times higher than that of the matrix

greatly enhancing the wear resistance of the WCP/steel composites.