Pin-on-Disc Study of Tribological Performance of Standard and Sintered Gear Materials Treated with Triboconditioning Process: Pretreatment by Pressure-Induced Tribofilm Formation

ABSTRACT

Coating is one of the innovative approaches used to improve the wear resistance and load-carrying capacity of surfaces in rolling–sliding contact, such as gears and rolling element bearings. In this study, the tribological performance of standard gear material (EN 16MnCr5) and two kinds of powder metallurgy (PM) gear material (Distaloy AQ + 0.2% C and Astaloy 85Mo +0.2% C) with and without tribofilms formed by a pretreatment were evaluated. Specimens treated with the pretreatment and the substrate were subjected to pin-on-disc tests under boundary lubrication conditions. The friction and wear performance of the two different PM gear materials with the pretreatment-formed tribofilm were compared to RS-RS (EN 16MnCr5 material disc and pin combination) for reference. It was found that the pretreatment lowers the friction coefficient and enhances the wear resistance of pins because of the tribofilm formed. The tribofilm caused good running-in due to the existence of and Fe and W oxides. Mo-Mo (Astaloy 85Mo + 0.2% C material disc and pin combination) and Mo-RS (Astaloy 85Mo + 0.2% C disc and EN 16MnCr5 pin combination) showed statistically significant higher wear resistance.

KEYWORDS:

• Gear material
• powder metallurgy
• pretreatment
• wear
• friction

Acknowledgments

Thanks are expressed to Dr. Michael Andersson and Engineer Marcus Persson from Höganäs AB for their guidance and technological support.

Funding

This project was financially supported by Höganäs AB. The pretreatment was performed by ANS.