The fabrication and characterizarion of nano particle reinforced-copper matrix functionally graded electrical contact materials

The aim of the present work was to study the production of nano particle reinforced Cu matrix functionally graded electrical contact materials using powder metallurgy method and to investigate the relationship of the particle type and particle content with physical properties, mechanical properties, wear resistance and arc erosion behavior of fabricated electrical contact materials. The effects of reinforcement type and weight percentage (wt%) on the physical and mechanical properties of the the composites were determined by measuring the density, electrical conductivity and hardness values. At the second step, the nanocomposites providing the best conductivity, the best wear resistance and the best contact performance was used for the production of functionally graded electrical contact materials. The electrical conductivity is in the range of 78.5-61.5 IACs for sintered Cu-graphene nanosheets nanocomposites. Hardness of Cu-nanographite and Cu-carbon nanotube nanocomposites is lower than that of the Cu-graphene nanosheet nanocomposites. It was observed that the wear resistance of Cu-based nanocomposites has been improved significantly when graphene nanosheet particles are used as reinforcement particles. Compared to monolithic copper and Cu-Carbon nanotube samples, Cu-nanographite and Cu-graphene nanosheet nanocomposites show the remarkable improvement on the arc erosion behavior due to higher electrical conductivity and acceptable wear resistance. Microstructure and properties of functionall graded materials shows that the gradation resulted in a remarkable enhancement of electrical conductivity, hardness, wear resistance and arc erosion properties. The electrical conductivity of FGM samples was changed from 73 IACs to 90 IACs along the thickness. The Brinell hardness of FGM samples was changed from 29 IACs to 34 IACs along the thickness. Wear rate and arc erosion rate were decreased by using two and three layers FGM.