CHARACTERIZATION OF NANOCOPPER/GRAPHITE COMPOSITES SYNTHESIZED BY PM ROUTE

摘要

The self-lubricating composites were produced from nano-copper based containing graphite by 0, 2.5, 5, 7.5 and 10 wt%. Nano-Cu /graphite composite were fabricated using a conventional powder metallurgy process. These mixtures were uniaxially pressed by applying different loads from 300 up to 1200MPa and three sintering temperatures at 900, 950 and 1000℃ for 2hr. The particle size and shape of powders as well as the microstructure after sintering were investigated by using field emission scanning electron microscope "FE-SEM" and X-ray diffraction "XRD". The density, hardness, compression, sliding wear and friction behavior of the nano-Cu/graphite composite were investigated. The results showed that the relative green density is directly proportional to the applied load and inversely proportional to the content of graphite. Nano-Cu/graphite composites fabricated under 700 MPa and sintered at 1000℃ for 2 hr recorded the highest relative density, hardness and compression strength. It exhibited the lowest wear rate and coefficient of friction, in which they decreased with increasing graphite content. It was found that the graphite free sample properties compacted at 700 MPa and sintered at 950℃ for 2 hr recorded the highest relative density, mechanical and tribological properties. The microstructure observations concurred with these results.