The effect of magnetic field on fretting wear

The effect of magnetic field on fretting wear of ferrous materials was examined using a fretting wear test under Hertzian contact conditions. Vertical magnetic fields of 0.01 and 0.13 T, created by permanent magnets, were applied to the contact. The amplitude of the fretting test was 10 μm and the normal load on the contact between a nominally flat surface and a steel ball of 20 mm in diameter was in the range of 40–100 N. Experiments were carried out in air and low vacuum conditions. From the tests in air, it was found that the width of the fretting scar increased under the influence of magnetic field. It is thought that this increase is due to an abrasive action by entrapped, within the contact zone, wear particles produced by magnetic field. Similar tests performed under low vacuum conditions resulted in appreciably smaller fretting scar. A possible mechanism of fretting wear under the influence of magnetic field is proposed and discussed.