Reciprocal tribocontact of biomedical alloys

Reciprocal Tribocontact has been manifested to be responsible for the certain attrition of artificial components in dental fields. But confusion on the aspects of friction and wear pattern was found between fretting and sliding, the two items often emerging in reports about friction and wear of biomaterials, due to the ambiguity on definition. By refining the definition of fretting with partial slip concept, this work compared friction and wear behaviors of three dental alloys under fretting and sliding conditions. Results indicate that friction force waveform and surface damage topography created by fretting quite differs from by sliding. The curve of friction force vs time under fretting is of nearly perfect sine waveform; some micro disturbance occurs on the peaks and valleys of the waveform while the amplitude is big enough. Wear patterns from fretting consist of a central stick region, a surrounding slip region and sometimes crack between the two regions, but wear patterns from sliding are of linear tracks running through the entire scar, scraped trace or severe surface deformation.