The tribological behavior of MoS2-Cr films sliding against an aluminum counterface

The tribological performance of MoS2-Cr films in a pin-on-disk test sliding against an aluminum ball has been examined in this study. The MoS2-Cr films were deposited by pulsed laser deposition (MoS2) and simultaneous sputter deposition of Cr, giving a Cr content in the film of 10 mol. %. The results were also compared with films Of MoS2 alone. The frictional behavior of MoS2-Cr films was not improved compared to the MoS2 alone, so SEWEDS studies of the ball and flat were conducted to determine the nature of the transfer films and examine any interface reactions that occurred during the pin-on-disk (POD) test. In the early stages of the POD test (500 cycles) on the MoS2-Cr film, Al-oxide particles formed and caused cratering and scratching of the wear track, and the coefficient of friction neared 0.7. At later stages (9000 cycles), a thick oxide-based transfer film formed on the ball, but on the flat the track composition was closer to that of the original coating. For the films without Cr, after 104 cycles a smooth wear track was observed, and a thin transfer film Of MoS2 was found within grooves on the ball wear scar along with Al oxide, which resulted in superior tribological performance.