波箔气体轴承WC-12Co涂层的制备和性能研究

Research on the Preparation and Performances of WC-12Co Coatings for Gas Bump Foil Bearings

为降低波箔轴承的摩擦磨损,采用等离子喷涂技术在圆盘试样和波箔轴承轴套表面制备WC-12Co涂层,采用自制销盘摩擦磨损试验机研究圆盘试样的摩擦磨损性能,通过扫SEM和EDS分析涂层摩擦磨损前后表面和截面形貌和面能谱,利用波箔轴承实验平台探究涂层实际使用过程中的摩擦磨损性能。结果表明:涂层和基底分界线明显且结合紧密,涂层整体由片状颗粒堆叠而成,片状颗粒之间分布有非常微小的孔隙,涂层的结合方式以机械结合为主,伴有一定的冶金结合方式;销盘摩擦磨损试验结果表明,WC-12Co涂层具有很好的耐磨和减摩性能,其平均摩擦因数相对GCr15轴承钢减小约50%,平均磨损量相对减小约78%。波箔轴承台架试验结果表明,WC-12Co涂层也表现出非常好的耐磨和减摩效果,WC-12Co涂层轴套启动时的最大摩擦力矩大幅下降。

In order to reduce the friction and wear of bump foil bearing,the WC-12Co coatings were prepared by plasma spraying technology in disc specimens and bearing sleeves of bump foil bearings＇ surfaces.Friction and wear properties of disc specimens were studied on a homemade pin disk friction and wear tester.The morphology and energy spectrum of friction and wear surface and cross section before and after test were analyzed by SEM and EDS.Friction and wear properties of the coatings used in the actual condition were explored by a bump foil bearing experiment platform.The results show that the boundary of coating and the substrate is clear and the coating and the substrate are combined closely.The whole coating is composed of stacked lamellar particles,and some very tiny pores are distributed in stacked lamellar particles.The combination way of coating is given priority to mechanical bonding,accompanied with a certain way of metallurgical bonding.The results of pin-disk friction and wear test show that the WC-12Co coating applied to the specimens has good friction reducing and anti-wear properties,the average friction coefficient of WC-12Co coatings is reduced about 50% and the average wear quantity is reduced about 78% compared with GCr15.The results of bump foil bearing experiment platform test show that the WC-12Co coating also shows very good friction reducing and anti-wear properties,and the starting friction torque of the the bearing sleeves with WC-12Co coating is reduced greatly.