Çelik, Ilhan; Karakan, Mehmet; Bülbül, Ferhat

In the present study, the surface of commercial pure (Grade 2) titanium was coated with electroless Ni-B and, then, it was subjected to heat treatment for an hour at 400°. The surface morphology, microstructure and phase identification were analysed by X-ray diffraction and scanning electron microscope. Wear behaviour characterisation was carried out using a ball-on-disc tribometer. The results of the analyses showed that the electroless Ni-B coating had a significantly amorphous structure in the as-deposited condition. It was also determined that the coating structure crystallised after the heat treatment and wear resistance of pure titanium increased after electroless Ni-B coating. Particularly, upon the heat treatment, it was observed that wear resistance and surface hardness of pure titanium considerably increased.

Ekmekci, Dursun; Bülbül, Ferhat

Ni-B/SiO2, Al2O3, TiO2 and CuO composite coatings were successfully obtained by the electroless plating technique. Dispersible SiO2, Al2O3, TiO2 and CuO nanoparticles were co-deposited with electroless Ni-B coating onto AISI-304 steel substrates. Deposits were characterized for its structural properties by X-ray diffraction (XRD). XRD results showed a broad peak of Ni-B and low intensity composite nanoparticle peaks. The surface and cross-section morphology of samples were analysed using a scanning electron microscope (SEM). Surface analysis showed that the incorporation in Ni-B matrix of nano-SiO2, Al2O3, TiO2 and CuO particles increases the nodularity of composite coatings. The deposits are composed of a columnar structure grown along the vertical direction of the substrate surface. The results also show that electroless nanocomposite coatings tend to have greater microhardness compared with the coating without nanoparticles. The increase in the microhardness of the nanocomposite coatings reported in this study is attributed to an effect of dispersion strengthening of ceramic particles in the Ni-B matrix.

Bülbül, Ferhat; Çelik, Ilhan

Pure titanium has a very large potential for use industrially due to its low weight, however, its usage continues to be limited because it possesses some disadvantages such as low hardness and wear resistance, weak corrosion resistance in high temperatures and high cost. In order to strengthen these weaknesses of pure titanium, electroless Ni-B deposition process, may be an alternative solution. In this study, the Ni-B coatings were deposited on pure titanium and annealed at the temperatures of 450 degrees C, 650 degrees C and 850 degrees C. The non-heat treated and heat treated coatings were structurally characterized via SEM (scanning electron microscope) and XRD (x ray diffraction). These coatings transformed from amorphous structure to a pronounced crystalline structure depending on heat treatment.