Investigation of the tribological behavior of an aluminum alloy with embedded materials

Aluminum alloy-based (LY-12) composites were made by embedding pins of bearing steel, plain carbon steel, brass, copper, graphite, and polytetra-fluoroethylene (PTFE). The surface area ratio of the embedded phase was 39.1%. The tribological behavior of the embedded composites was evaluated under dry friction and lubricated with a bonded solid lubricating film outer-layer on a reciprocating friction and wear tester at ambient conditions. The morphologies of the worn surfaces and of the transfer films on the counterpart surfaces were observed with a scanning electron microscope. The tribological behavior of the embedded composites was highly dependent on the hardness of the embedding materials. Friction and wear of Al alloy can be drastically reduced by proper embedding, but embedding with solid lubricants such as graphite and PTFE does not help. Friction and wear behaviors were different in sliding against Al and plain carbon steel. The observation of the worn composite surfaces by SEM indicates that wear of Al-based composite blocks is characterized by plowing, severe adhesion, and plastic deformation.