Çelik, Ilhan; Karakan, Mehmet

In this study, plasma nitriding treatment was applied to commercially pure titanium (Grade 2). Structural properties, electrochemical and tribological behaviours of the nitrided pure titanium specimens were comparatively investigated. Microstructure and morphology of the plasma nitrided specimens were analysed by X-ray diffraction and scanning electron microscopy. Furthermore, corrosion tests were conducted in Ringer's solution, which represents a human body environment, to determine electrochemical properties. Then, tribological and frictional properties were investigated using pin-on-disc tribometer, and a micro-hardness tester was used to measure the hardness of the coatings. The results showed that plasma nitrided specimens exhibited higher surface hardness than the untreated specimens did. In addition, the plasma nitrided specimens at 700 °C presented significantly better performance than the other plasma nitrided specimens (at 500 °C and 600 °C) under dry wear conditions. Moreover, corrosion test results showed that corrosion behaviours of untreated and nitrided samples had similar characteristic.

Çelik, Ýlhan; Karakan, Mehmet

The structure and the wear resistance of commercial-purity titanium subjected to plasma nitriding followed by chemical deposition of a Ni – B coating are studied.

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.