Ambiguous Transition from Fretting to Sliding of Biomedical Alloys

摘要

An intensive amplitude arrangement for reciprocal tribocontact of biomedical alloys, Ag-20.0Pd-14.5Cu-12.0Au, Au-5.0Pt-2.0Pd-9.2Ag-15.0Cu and Ti-29Nb-13Ta-4.6Zr was conducted in order to elucidate the details of friction and wear alterations which denote the transition from fretting to sliding. We show that the friction force exhibits stagnation for the Ag alloy and a decrease for the Au and Ti alloys under a particular domain of oscillating amplitude. Not only did we find that beyond the domain, the friction force increases with the amplitude, but we also note that below the lower threshold and above the upper threshold, the observed triboevent is complete fretting and sliding, respectively. Observations of the friction-force waveform and SEM topography found a hybrid mechanism of fretting and sliding is dominant in the amplitude domain, and the strong adhesion between the self-mated alloys is responsible for this exhibition.