Magnetization of friction surfaces and wear particles by tribological processes

The relationship between magnetization of a friction surface and wear phenomena is discussed for the case of rubbing of nickel on nickel. Experiments were performed by sliding-friction tests of the pin-on-block type. Magnetization of the friction surface was estimated by measuring changes in the magnetic flux density with a Tesla meter, and the effects of lubrication and various normal loads on changes in the magnetic flux density were examined. Also, the magnetic flux density of wear particles was examined for single particles and particle aggregates. The magnetization of the friction surface was found to be related to surface damage by transfer (adhesion). Individual wear particles and aggregates of fine wear particles were all magnetized in one direction by tribological action, showing that wear particles and transfer particles on the friction surface are the principal source of magnetization.