Examination of friction and wear of a 100Cr6 ball against a bearing ring in a micro-pin-on-disk tester

Abstract

Understanding the wear and friction phenomena in bearings is of key importance for the reduction of friction and wear. Boundary layers formed by oil additives during operation may significantly influence the frictional behaviour. To investigate the behaviour of such layers standardised test runs with cylindrical roller thrust bearings were conducted using differing oils with varying additivation. For these tests a FE-8 test rig for characterisation of rolling contact bearing lubricants was applied. As oil a low reverence and high reverence oil, as well as differently additivated oils were used. These oils may result in different boundary layers on the wear tracks. To analyse the frictional behaviour of these layers on the bearing surface, a micro-pin-on-disk tester was used under very low load. The contact of a spherical pin (made of 100Cr6) on a bearing disk (also called washer) without lubrication was examined. As a counterpart the bearing disks were used after the run in a bearing test rig under various oils, unused, and etched on the surface. Before application on the micro-pin-on-disk tester, all adhesive oil was removed. During the tests the coefficient of friction was monitored. The tests were performed at a rotational velocity of 1 min-1, the load was 27 mN.