Temperature studies using positron lifetime spectroscopy of the subsurface zone in pure titanium exposed to a dry sliding test

Abstract

The report presents the positron annihilation studies of subsurface zone generated in pure titanium exposed to a long period dry sliding test. The total depth of the subsurface zone induced is detected at about 250 µm. Only dislocations and vacancy clusters which consist of two or three vacancies are observed in this zone. Their concentration decreases with the depth, especially at the depth above 100 µm. Despite the long duration of the sliding test, no clear signs indicating the presence of a tribolayer were observed. This was confirmed also by observation of annealing of defects in this zone at different depths. The lack of the tribolayer is in contrast to the research done so far for other metals.