Investigation of Tribological Performance of Composite Nanodiamonds and Graphene Nanoplatelets-Reinforced Alumina Coatings at High Temperature

Multifaceted coatings are in high demand due to their remarkable tribological advantages and fortification from harsh environments. However, ceramics coatings perform well and offer excellent performance but are limited to high temperatures. In the present study, it is perceived that 0.1 wt% nanodiamonds and 1 wt% graphene nanoplatelets reinforced in Al₂O₃ offered improved wear-resisting properties at high temperatures from 300 to 500 °C. The measured relative density recorded was 94.45 ± 1.9, 95.45 ± 0.9, and 97.25 ± 1.9 for A-SD, AND-SD and ANDG-SD, respectively. The wear rate decrement on 10N, at 300 °C, of AND-SD was recorded at 50.12% and 74.50% in ANDG-SD. On 15N, at 400 °C, 48.35% for AND-SD and 64.31% for ANDG-SD were recorded. The highest wear rate reduction, i.e., 74.66%, was recorded in ANDG-SD at 500 °C. The COF value at an applied load of 10N at 300 °C was 0.49, 0.46, and 0.30 for A-SD, AND-SD, and ANDG-SD, respectively. At an applied load of 15N, at 400 °C, it was 0.51 for A-SD, 0.42 for AND-SD, and 0.29 for ANDG-SD. At an applied load of 20N, at 500 °C, 0.54 for A-SD, 0.40 for ANDG-SD, and 0.24 for ANDG-SD were recorded. The maximum decrement in COF value was observed at an applied load of 20N, at 500 °C, due to GNP’s self-lubricating properties, which have the exceptional caliber to enhance wear resistance. Through this study, it has been supposed that developed hybrid coatings could be a robust path for developing coatings at high working temperatures.