Wear and friction characteristics of surface-modified aluminium alloys

This study investigates the wear and friction characteristics of surface–modified aluminium alloys of JIS AC4CH–T6 and A6061–T651. The aluminium alloys were individually treated with five surface modifications, including anodising, anodising/MoS2, electroless Ni, electorless PTFE and DLC. Dry wear tests of thrust–washer–type specimens were carried out at room temperature to evaluate the tribological behaviours of the coatings. The results indicate that coatings effectively enhanced specimen hardness and the surface roughness of the anodising coatings was affected by the choice of base materials. That is, the roughness of the anodised A6061–T651 aluminium alloy was superior to that of the anodised AC4CH–T6. The worn morphology shows wear mechanisms which vary with the coatings. Low–friction coatings of EN/PTFE and DLC exhibited higher wear resistance because of a lower level of material softening caused by the induced friction heat during the wear tests.