Nickel-based nanocoatings were prepared on AISI-1045 steel sheet by
electro-brush plating. The average grain size and microstructure
of the nickel nanocoatings heated at different temperatures for 2 h were examined by means of X-ray diffraction and atomic force microscopy. The microhardness and wear behavior of the nanocoatings were investigated. The worn surface morphologies of the nanocoatings were observed using a scanning electron microscope. It was found that the average grain size, the hardness, and wear-resistance of the
Ni-based nanocoatings were greatly dependent on the heat treatment temperature. Namely, the heat treatment at a proper temperature led to a decrease in the grain size of the Ni-based nanocoatings, while the hardness and wear-resistance of the nanocoatings were greatly increased after the heat treatment. This led to a change in the wear mechanisms of the untreated and heat-treated nanocoatings as well. In other words, the untreated Ni-based
electro-brush plating coating was dominated by severe adhesion wear and scuffing, while the coating heated at 300 ℃ for 2 h was dominated by brittle cracking. Moreover, the Ni-based electro-brush plated coating heated at 300 ℃ for 2 h had an average grain size below 30 nm and the largest hardness, while the nanocoating heated at 200 ℃ for 2 h had the best wear-resistance. The increased hardness and wear-resistance of the Ni-based electro-brush plated coating were attributed to the decreasing in the grain size and increase in the compactness of the coating after proper heat treatment.