Effects of the oxide layer formed on TiN coated silicon wafer on the friction and wear characteristics in dry sliding

In this study, the effects of the oxide layer formed on the wear tracks of titanium nitride (TiN) coated silicon wafer on friction and wear characteristics were investigated. Silicon wafers were used as the substrate of coated disk specimens, which were prepared by depositing TiN coating, 1 μm in thickness. SAE 52100 steel balls were used as the counterpart. The tests were performed both in air for forming an oxide layer on the wear track and in nitrogen to avoid oxidation. This paper reports characterization of the oxide layer and its effects on friction and wear characteristics using X-ray diffraction, Auger electron spectroscopy, scanning electron microscopy and multi-mode atomic force microscopy. The TiN coating with the oxides shows relatively high friction compared to that without an oxide layer. The thickness of the layer formed on the surfaces of the TiN coated silicon wafer is very thin compared to the thickness of the TiN coating. The oxide layer dominates the frictional characteristics between the two materials and induces a relative high friction.