Wear mechanisms of alumina ceramics in unlubricated rolling-sliding contact (Effect of tribo-film on wear process)

Wear mechanisms of alumina ceramics in unlubricated rolling-sliding contact were investigated based on observation of wear surfaces and wear particles using a scanning electron microscope. Wear particles can be divided into two types, namely powder like wear particles and plate like ones. The sizes of powder like or plate like wear particles are generally on the order of sub microns or several hundred microns, respectively. Powder like wear particles are compacted on the roller surface in the process of repeated contact and form a tribo-film, whose thickness changes up to several microns depending on slip ratio. Tribo-Film delaminates partially as plate like wear particles by propagation of cracks after repeated contact. As a result, formation and delamination of tribo-film control the wear process of alumina ceramics in unlubricated rolling-sliding contact.