Preparation of a novel multi-layered AlSnCu coating for journal bearings

This paper described preparation process and tribological performance of a novel overlay material used in journal bearings. A new kind of multi-layered AlSnCu coating with good wear resistance and high load capacity was fabricated by arc assisted magnetron sputtering method. The multi-layered structure was implemented by the intermittent sputtering of Al target during the continuous sputtering of AlSnCu target. As a result, the normal growth of Sn crystals was interrupted by introducing periodic sputtering of Al target, which reduced the size of Sn particles in AlSnCu coating. These small size Sn particles played better anti-friction function under both dry and lubricated conditions. Especially, the self-formed Sn-oil synergic lubricating film played a vital role to enhance its tribological performance in oil environment even under a high applied load of 30 N. Therefore, this novel multi-layered AlSnCu coating with small Sn phase displayed considerable application prospects in journal bearings of diesel engine.