Tribological behavior of plasma-sprayed metal based solid self-lubricating coatings under heavy load

Metal based solid self-lubricating coating is an important way to reduce the wear of friction pair and has been widely employed in several friction conditions. However, its application in some extreme environments especially under heavy load condition is still insufficient. In this study, the tribological behavior and wear mechanism of three typical metal based solid self-lubricating coatings such as Ni-graphite (Ni-G), Ni-MoS2 and tin bronze (Cu-Sn) were comparatively studied by a pin-on-disk wear test against 1Cr15Ni4Mo3N steel counterpart coated with NiCr-Cr3C2 under the load up to 52 MPa. The results showed that under heavy load condition, the failure of Ni-G or Ni-MoS2 coating was related to abrasive and delamination, while the predominant wear mechanism of Cu-Sn coating was adhesion. The Ni-G coating and Cu-Sn coating displayed the lowest coefficient of friction and the lowest wear rate, respectively. The wear resistance of coating was highly dependent on mechanical prop-erties. Particularly, plasticity and toughness should be given more attention when tailoring metal based solid self-lubricating coating under heavy load condition.

Automated summary

This study compared the tribological behavior and wear mechanism of three typical metal-based solid self-lubricating coatings under heavy load conditions. It was found that Ni-G and Ni-MoS2 coatings failed due to abrasive and delamination wear mechanisms, while Cu-Sn coating primarily exhibited adhesive wear. Ni-G coating and Cu-Sn coating showed the lowest coefficient of friction and wear rate, respectively, under heavy load conditions. The wear resistance of the coating was found to be strongly influenced by mechanical properties, especially plasticity and toughness when designing metal-based solid self-lubricating coatings for heavy load conditions.