CHARACTERIZATION- AND SYNTHESIS OF GRADED NICKEL-GRAPHITE COMPOSITES BY POWDER METALLURGY TECHNIQUE

Abstract

Nickel-Graphite graded material has been prepared by a powder metallurgy die compaction process followed by sintering subsequently cold rolling operation. The final, sintered samples have a gradient in carbon content, with a maximum value of 7 wt. %. The results were confirmed after seeing the microstructure of graded and monolithic components. The results further reveled that an increase in the weight percentage of carbon particulate leads to a concurrent increase in green compact thickness. The results further revealed that there were slightly crack deformations during compaction processes. The results further revealed that thickness of monolithic components was found to decrease after sintering. As the weight percentage of carbon in Ni-C monolithic layer increases, the magnitude of the green compact thickness also increases. The results further revved that an increase in the weight percentage of carbon particulate leads to a concurrent increase in green.compact thickness. In an effort to investigate the effect of thickness reduction on rolling, monolithic and graded Ni-C composites. The effects of weight percentage of graphite particles in graded and monolithic Ni-C composite were investigated. In the graded Ni-C alloy, it was found that thickness found to be decreasing after sintering as compared to cold pressing. In Ni-C graded alloy, the .cracks start from high carbon content side to low carbon content side. It was also found that, as the thickness of Ni-C layer increases, the magnitude of the reduction in cross-section decreases. In this study particular attention is paid on die compassion technique and also Further study on deformation analysis and Hardness calculations. The microstructures of sintered, rolled and re-rolled graded and monolithic compact were determined by optical microscopy. Further SEM (Scanning Electron Microscopy) and X-Ray Diffraction analysis have been studied.