Microstructure And Mechanical Properties Of Ceramic Nanoparticles Embedded Ni-P Composite Coating

TiN monocrystal nanoparticles had been prepared by a DC arc discharge method in a mixture atmosphere of hydrogen and nitrogen. The crystal structure and microstructures were studied by means of XRD and TEM. The oxidability of nanoparticles was studied by TGA-DTA. It was indicated that the TiN nanoparticles were monocrystal. At 774 K, TiN nanoparticles were oxidated.TiN nanoparticles embedded Ni-P/TiN nano-composite coating were prepared by electro-brush plating. The morphology and microstructures were studied by means of XRD and SEM. The micro-hardness and tribological properties of the nano-composite coatings were also investigated. Ni-P/TiN nano-composite coating had about 3 times higher micro-hardness than Ni-P coating and its wear resistance was also improved.α-Al2O3 nanoparticles embedded Ni-P/Al2O3 nano-composite coating were also prepared and tested by the same method. Compared with Ni-P coating, Ni-P/Al2O3 nano-composite coating was annealed at 200℃,400℃, and 600℃in vacuum for 1 h. The effect of the temperature was studied. The composite coating has been crystallized at 400℃. Ni-P/Al2O3 nano-composite coating annealed at 400℃had the best mechanical properties.