Study on the characteristics of Ni-W-P composite coatings containing nano-SiO2 and nano-CeO2 particles

The aim of this research work was to co-deposit nano-SiO2 and nano-CeO2 particles into the Ni-W-P alloy coating in order to improve the surface properties further. Ni-W-P-SiO2-CeO2 composite coatings were prepared by co-deposition of nickel, tungsten, phosphorus, nano-SiO2 and nano-CeO2 particles on the surface of 15 steel from the electroplating bath which nano-SiO2 and nano-CeO2 particles were suspended by high speed mechanical stirring. The characteristics of the composite coatings were assessed by micro hardness test, Taber Abrader test, scanning electron microscopy and X-ray diffraction. The results obtained in this study indicate that the nano-SiO2 and nano-CeO2 particles were dispersed evenly within the Ni-W-P alloy coating and the bonding between the matrix metal and nano-SiO2 and nano-CeO2 particles is compact. That the co-deposition of nickel, tungsten, phosphorus, nano-SiO2 and nano-CeO2 particles leads to uniform Ni-W-P-SiO2-CeO2 composite coatings possessing better micro hardness and abrasion resistance properties when heat-treated at 400 °C for 3 h. In addition, that nano-CeO2 and nano-SiO2 particles can increase the thermal stability of Ni-W-P alloy coating at high temperature.