Properties Comparison of α-Al₂O₃ Particles and γ-Al₂O₃ Particles Reinfcrced Ni-P Nano-composite Coatings

The α-Al2O3/Ni-P and γ-Al2O3/Ni-P nano-composite coatings were prepared by electroless deposition with embedded nanometer-sized α-Al2O3 and γ-Al2O3 particles.The phase structure,surface morphology and element distribution of nano-coatings were studied by means of XRD,SEM,EPMA.The micro-hardness,tribological properties and corrosion resistance were investigated and compared with those of Ni-P coating.The retults show that in comparison to the conventional Ni-P coating,the structure of the coating was not changed due to the addition of nano α-Al2O3 particles,but the co-deposited nano-coatings had higher micro-hardness.The wear resistance and corrosion resistance of the coating with nano α-Al2O3 particles were improved,but that with γ-Al2O3 were decreased.