Mechanical Milling Prepared Nano-Sized Al₂O₃ Particles Utilized in Electroless Plating Ni-P- Al₂O₃ Composite Coatings

In this paper, nano-sized Al2O3 particles were prepared by mechanical milling, and Ni-P-Al2O3 composite coatings were plated on Q235 steel substrates, which plating solutions were containing different concentrations Al2O3 particles. The morphology, phase and particle size distribution of the as-prepared Al2O3 particles, and the properties of the coatings were investigated. The results show that, the morphology of the as-prepared Al2O3 particles were spherical and almost size under 100nm, the coatings were uniformly thickness and the Al2O3 particles were uniformly dispersed in the coatings, after heat treatment, the micro-hardness and wear resistance of the coatings were significantly improved, compared with the chemical method prepared Al2O3 particles, the mechanical method prepared Al2O3 particles had the same performance in improving the micro-hardness of the coatings.