Production and characterization of Ni-B/TiC nanocomposite coatings by electrodeposition method for friction surfaces of internal combustion engines

Applying coatings to the frictional surfaces of internal combustion engine parts is a very efficient method to make the material more resistant to wear and corrosion. In scope of this study, stainless steel substrate material was coated with TiC ceramic nano-particle reinforced Ni-B alloy matrix composite film by electrochemical deposition method. In the coating process, Watts type nickel electrolyte was taken as basis, and suitable materials were added to the bath in order to obtain alloy and composite coatings. The enhanced properties of the produced Ni-B/TiC nanocomposite coatings were investigated by comparing them with stainless steel substrate, pure nickel, Ni-B alloy and Ni/TiC coatings. The effects of TiC particle bath concentration, boron source trimethylamine borane (TMAB) bath concentration and deposition current density variation on nanocomposite coatings, which are among the electrodeposition production parameters, were investigated. In order to characterize the properties of these new types of materials, their wear and corrosion behavior and crystal structures were analyzed, microhardness measurements were carried out, and the morphology and chemical contents of the coatings were investigated. In addition, electrochemical analyzes of the electrolytes from which the coatings produced were also carried out. Moreover, model development studies were carried out so as to predict the experimentally measured microhardness and crystal grain size values of the obtained coatings by artificial neural network (ANN) method. According to the results gained in this study, the nanocomposite coatings produced have improved significantly in mechanical and corrosion properties compared to stainless steel substrate, pure nickel, Ni-B alloy and Ni/TiC coatings, and it has been proven to be a suitable alternative for machine parts especially in hard operating conditions. Key words: TiC, Ni-B alloy, electrodeposition, wear, corrosion