Abstract:
TiN and TiAlN nitride coatings were deposited on GCr15 bearing steel by arc ion plating. The microstructure, hardness, bonding property, impact resistance and wear resistance of the coatings were studied comparatively. The results show that the surface of the prepared TiN coating and TiAlN coating was flat, and both of them grew optimally with (200) crystal surface. The hardnesses of TiN coating and TiAlN coating were 2 060.3, 3 390.8 HV, which were 3.0 times and 4.9 times that of the substrate (689.5 HV), respectively. The bonding property of TiN and TiAlN coating with bearing steel was good, and the bonding grade was HF1-HF2. After impacting for 40 times, there was no spalling and cracking on the surface of TiN and TiAlN coating, and the impact resistance was good. After friction with bearing steel, the average friction coefficients of TiN coating and TiAlN coating were 0.42 and 0.36, and the volume wear losses were 1.26×10
-3, 0.54×10
-3 mm
3, respectively, which were lower than those of the substrate. The shallow furrows were formed on the surface of TiN and TiAlN coating after wear, and the wear mechanisms were both abrasive wear. The furrows on the surface of TiAlN coating were shallower and the wear degree was lighter than those of the TiN coating. The bonding property and impact resistance of TiAlN coating were comparable to those of TiN coating, and the hardness and wear resistance of TiAlN coating were higher than those of TiN coating. TiAlN coating was more suitable for improving the surface wear resistance of bearing steel.