Influence of the content of Si_3N_4 in electrolytic nickel composite coatings on changes of their tribological properties

摘要

In the present study the relation between the content of Si_3N_4 and tribological properties of nickel-silicon nitride surface coatings, produced by the electrochemical process on a steel substrate, has been examined. Investigations of the morphology and the phase composition of Si_3N_4 powder are performed. Suitable parameters for the deposit process of Si_3N_4 coatings are determined. A detailed analysis of the structure of the manufactured composite coatings has been presented. The volumetric content of the disperse phase in the deposited coatings has been examined. Results of examinations of the wear resistance and hardness of the Ni and Ni-Si_3N_4 coatings, respectively, are reported. Increase of microhardness with the volumetric content of the ceramic phase in the composite coating is exhibited. Changes of tribological properties with the content of Si_3N_4 in the studied coatings are demonstrated.