Abstract
The annealing behavior of the subsurface zone (SZ) in pure bismuth induced by dry sliding was studied using the positron lifetime measurement. This measurement allows us to detect the SZ and its recovery, and recrystallization processes. The comparative measurements of the sample exposed to compression revealed the thermal stability of the SZ. The compressed sample rebuilt its structure due to the recovery and recrystallization processes at the temperature of 60 °C, whereas the sample exposed to dry sliding does it at higher temperature of 260 °C, which is close to the melting point. The isothermal annealing at the temperature of 100 °C confirmed these results. The defect depth profile induced by dry sliding evolves with the annealing temperature in such a way that the concentration of defects at the worn surface gradually decreases, but at the depth between 50 and 170 μm, the generation of new defects takes place at the temperature of 75, 100 and even at 175 °C. At the temperature of 175 °C, the defects still are extended up to the depth of about 60 μm from the worn surface. The results were qualitatively confirmed by the measurements of the Vickers microhardness depth profile. Similar annealing behavior of the SZ was observed in pure magnesium.
Highlights
The sliding contact of two ductile bodies induces the hardening of the worn surface and the adjoined subsurface zone (SZ)
We used the pure bismuth samples whose surfaces were damaged in the dry sliding or which were compressed
The annealing behavior of the SZ in pure bismuth exposed to dry sliding detected by positron annihilation reveals its high thermal stability in comparison with the compressed sample
Summary
The sliding contact of two ductile bodies induces the hardening of the worn surface and the adjoined subsurface zone (SZ). This is due to the repeating passage of asperities of the counterface, which leads to the accumulation of strains in a loaded surface and below. The interesting review of the topic of wear and material structure is given by Zum Gahr in his book [1] As it was pointed out by Suh and coworkers in a ‘‘delamination’’ theory of wear, dislocations play a significant role in voids and crack nucleation [2,3,4]. The studies of dislocations and generally defects in the SZ are necessary for better understanding of wear [6]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
