• Yaqoob, Khurram
• Khalid, Hafiza Ayesha
• Yaqub, Talha Bin
• Fernandes, Filipe
• Cavaleiro, Albano
• Al-Rjoub, Abbas

Abstract

Alloyed-transition metal dichalcogenide (TMD) coatings have been under investigation as multi-environment lubricants for the past few decades. These coatings display very low coefficient of friction properties at elevated temperatures. Studies on the annealing of these low-friction coatings are missing in the literature. For the first time, in this study, the annealing of the W-S-N dry lubricant coatings was carried out to study its effects on the composition, morphology, crystal structure and hardness of the coatings. The W-S-N coatings were deposited by direct current (DC) reactive magnetron sputtering. The analysis was carried out for as-deposited, 200 °C and 400 °C annealed coatings. The as-deposited coatings have N content in the range of 0–25.5 at. %. The coatings are compact and the densification increased with the increase in N-alloying. All the coatings are crystalline except the highest N-alloyed coating which is X-ray amorphous. A maximum hardness of 8.0 GPa was measured for the coating alloyed with 23 at. % N. Annealing did not affect the composition and morphology of the coatings, while some variations were observed in their crystal structure and hardness. The maximum hardness increased from 8 GPa to 9.2 GPa after 400 °C annealing of the 23 at. % N-alloyed coating. ; This study is sponsored by FEDER National funds FCT under the projects: SMARTLUB ref.“POCI-01-0145-FEDER-031807”, CEMMPRE ref. “UIDB/00285/2020”, On-SURF ref. “POCI-01-0247-FEDER-024521”, “LA/P/0112/2020” and Atrito-0 ref. “POCI-01-0145-FEDER-030446”. ; info:eu-repo/semantics/publishedVersion

Topics

• impedance spectroscopy
• amorphous
• reactive
• hardness
• annealing
• densification
• coefficient of friction