轴承钢表面电弧离子镀氮化物涂层的抗冲击性能和耐磨性能

Impact Resistance and Wear Resistance of Nitride Coatings on Bearing Steel by Arc Ion Plating

采用电弧离子镀工艺在GCr15轴承钢表面分别沉积了TiN和TiAlN 2种氮化物涂层,对比研究了涂层的微观结构、硬度、结合性能、抗冲击性能和耐磨性能。结果表明:制备的TiN涂层和TiAlN涂层表面平整,均以(200)晶面择优生长;TiN涂层和TiAlN涂层的硬度分别为2060.3,3390.8 HV,为基体(689.5 HV)的3.0倍和4.9倍。TiN和TiAlN涂层与轴承钢的结合性能良好,结合等级为HF1~HF2,40次冲击试验后TiN和TiAlN涂层表面均未发生剥落和开裂,抗冲击性能良好。TiN涂层和TiAlN涂层与轴承钢对磨时的平均摩擦因数分别为0.42,0.36,体积磨损量分别为1.26×10^(-3),0.54×10^(-3 )mm^(3),均低于基体,涂层表面均形成了较浅的犁沟,磨损机制为磨粒磨损,其中TiAlN涂层表面犁沟更浅,磨损程度更轻。TiAlN涂层的结合性能和抗冲击性能与TiN涂层相当,硬度和耐磨性能均高于TiN涂层,更适用于改善轴承钢的表面耐磨性能。

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 2060.3,3390.8 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.