Abstract
Comparative analysis of dry sliding wear behavior of nanocrystalline diamond (NCD) films and NCD films coated with a thin Al2O3 layer (Al2O3/NCD) is the main goal of the present study. Plasma-enhanced chemical vapor deposition (PECVD) and atomic layer deposition (ALD) methods were used to prepare the NCD and alumina films, respectively. Sliding wear tests were conducted at room temperature (RT), 300 and 450 °C in air. Independent of type of specimen, superlubricating behavior with the coefficient of friction (COF) in the range of 0.004‒0.04 was found for the tests at 300 °C. However, the COF value measured on the Al2O3/NCD films in the tests at 450 °C is lower than that for the NCD film. A relatively short run-in period and a stable COF value of about 0.15 were observed at this temperature for the Al2O3/NCD films. The width of the wear scars measured on the Al2O3/NCD films after the tests at 450 °C is significantly smaller in comparison with the NCD film. The apparent wear volume of the wear scar on the NCD film tested at 450 °C was noticeably higher than that on the Al2O3/NCD films.
Highlights
Diamond is important engineering material due to outstanding properties including high Young’s modulus, hardness and low coefficient of friction (COF)
The peak positions are similar to the reflections from the nanocrystalline diamond (NCD) film investigated in our previous study of the NCD films grown on Si(100) and (110) single crystal diamond [12,13]; no peaks corresponding to Si and β-SiC were observed due to grazing incident set-up
To protect the NCD film against oxidation attack at high temperature in ambient air, the thin alumina layer was deposited on top of the NCD film
Summary
Diamond is important engineering material due to outstanding properties including high Young’s modulus, hardness and low coefficient of friction (COF). The fundamental drawback of carbon-based coatings (diamond like carbon and different types of diamond coatings) used in industry is the oxidation at high temperatures under ambient conditions, which strongly reduces the applicability of these materials at elevated temperatures. Diamond oxidation starts at >450 ◦ C in open air, i.e., in the presence of water and oxygen [1,2]. The tribological behavior of diamond coatings at high temperatures in ambient air has been studied in the past. Erdemir and Fenske [4] investigated friction and wear of the NCD films prepared on SiC in sliding tests against SiC pins at temperatures up to 400 ◦ C.
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.
