Frictional and wear behavior of commercially pure Ti, Ti-6Al-7Nb, and SUS316L stainless steel in artificial saliva at 310K

Abstract

Frictional and wear behavior of SUS 316L stainless steel, commercially pure Ti (Grade 2), and Ti-6Al-7Nb in artificial saliva and in deionized water were investigated at 310K using a ball-on-disc type frictional test machine with a Ti counterface. The present study aims to obtain information on the in vitro frictional behaviors of Ti-based dental metallic materials, and to investigate the morphological and compositional changes of the surface damages caused by wear and friction. The surface morphology and chemical composition of the wear track was investigated. The results obtained from the frictional test indicates an interpolated dynamic frictional coefficient ranging between 0.3 to 0.5 in both water and artificial saliva, which suggests that solid contact was predominant. The volume loss in water was always higher than that in artificial saliva and the volume loss of Ti-6Al-7Nb and SUS316L decreased with increase in the applied dead load. Microstructural observations suggests adhesive wear to be dominant in specimens tested in artificial saliva, whereas sharper grooves and cracks were frequently observed in the specimens tested in water. The results indicate that surface enbrittlement was caused by oxygen, and the strength of the materials was related to the wear and frictional parameters.