Influences of particle diameter on structure and hardness of Ni-SiC composite coatings

Ni-Si C composite coatings were respectively prepared with different diameter Si C particle of 30 nm,70 nm,1 μm,4μm and 7.5 μm as reinforced phase,and the influences of particle diameter on the morphology,structure and hardness were investigated. Results show that morphology,structure and hardness of the composite coatings change with the addition of particles. Furthermore,a composite coating with smooth surface,compact structure,high hardness up to 520 HV and obvious preferred orientation at(200)grain face can be prepared when using nano- particle as reinforced phase. The reason for the improvement of morphology,structure and property is attributed to the dispersion strengthening and refined crystalline strengthening effect.