Microstructure and properties of the Cp/AlSn coatings deposited by magnetron sputtering/multi-arc ion plating

Abstract In view of the failure of bearing bush due to their serious friction and wear and in order to improve deposition rate, Cp/AlSn self-lubricate coatings were prepared by magnetron sputtering/multi-arc ion plating. The coatings are uniform and Al, Sn and C elements are evenly mixed. With increasing of carbon target current, the grain sizes become smaller and smaller. The particles on the coating surface are “cobblestone-like”. The roughness decreases first and then increases with the increase of the carbon target current. The coating is composed of three layers. The working layer is equiaxed crystal mixed columnar crystal structure. The polycrystalline diffraction rings with Al and Sn elements have diffraction plane indexes of Sn Al (220) and Al (311), Sn (200) and Sn (211), respectively. The coating is of amorphous characteristic. Al and Sn elements exist in simple substance, and C element exists as graphite-like state with SP2 hybridization to form transfer film, improving the friction and wear performance. When the carbon current is 1.1 A, the bonding strength is 59 N, and the friction coefficient is 0.10. The Cp/AlSn coatings can improve the friction and wear performance of bearing bush.