Friction behavior of a multi-interface system and improved performance by AlMgB14-TiB2-C and diamond-like-carbon coatings

This study investigated friction behavior of a bearing system with two interfaces involved: a roller component experiencing rolling-sliding interaction against twin cylinders under point contacts while simultaneously undergoing pure sliding interaction against a socket under a conformal contact. Lubrication modeling predicted a strong correlation between the roller׳s rolling condition and the system׳s friction behavior. Experimental observations first validated the analytical predictions using steel and iron components. Diamond-like-carbon (DLC) coating and AlMgB14-TiB2 coating with a carbon topcoat (BAMC) were then applied to the roller and twin cylinders, respectively. Testing and analysis results suggest that the coatings effectively decreased the slip ratio for the roller-cylinder contact and the sliding friction at both bearing interfaces and, as a result, significantly reduced the system frictional torque.