干摩擦工况下Si3N4/PTFE配副材料摩擦磨损特性与转移膜形成分析

为使全陶瓷轴承在干摩擦工况下可靠运转,选用四氟乙烯(PTFE)材质的保持架为全陶瓷轴承提供润滑.利用Rtec销/盘摩擦磨损试验机,以PTFE盘与氮化硅(Si3 N4)销为摩擦副,研究Si3 N4/PTFE在不同载荷和转速条件下的摩擦磨损性能,通过SEM对Si3 N4表面的转移膜形貌进行观察,分析转移膜形成原因.结果表明...

Analysis on Friction and Wear Characteristics and Transfer Film Formation Mechanism of Si3N4/PTFE under Dry Friction Condition

In order to ensure the reliable operation of all-ceramic bearings under dry friction conditions,tetrafluoroethylene(PTFE)cage was selected to provide lubrication for all-ceramic bearings.The friction and wear properties of Si₃N₄/PTFE under different load and rotating speed were studied by using Rtec pin/disk friction and wear tester and taking PTFE disk and silicon nitride(Si₃N₄)pin as friction pairs.The morphology of the transfer film on the surface of Si₃N₄ was observed by SEM,and the formation reason of the transfer film was analyzed.It is found that the range of test parameters,the friction coefficient first decreases and then increases with the increase of load,and increases with the increase of rotating speed.The wear rate first increases,then decreases and then increases with the increase of load,and increases with the increase of rotating speed.PTFE transfer film will be produced in the friction process of PTFE/Si₃N₄ friction pair.The surface morphology of the transfer film is different under different load and speed,among which the filament-like transfer film has the best anti-wear and lubrication effect.The increase of frictional heat between the friction pairs causes the change of wear form from abrasive wear to adhesive wear,in which adhesive wear has a greater impact on the wear rate of PTFE.The transfer film produced by PTFE in the process of dry friction can play a role of anti-wear and lubrication,so PTFE can be used as a lubricating material for all-ceramic bearings under dry friction conditions.