Effect of extrusion ratio on the grain refinement and properties of copper prepared by powder metallurgy route

The present study emphasizes determining the optimum value of the extrusion ratio for superior microstructure and mechanical properties of copper via the synergistic effect of powder metallurgy and extrusion process. In this study, sintered Cu is hot extruded for different extrusion ratios, from 2.8 to 11.1. During extrusion treatment, copper experiences high compressive and shear stress, which enhances the nucleation rate and recrystallization. It also breaks the oxide precipitates into tiny pieces with uniform dispersion. Experimental evaluation of the extruded copper pallets analyzes the effect of extrusion ratio on compressive stress, density, micro-indentation hardness, and electrical conductivity for extruded copper components. These properties show a combined effect of grain refinement and compaction as a function and potential candidate for extrusion ratio. The impact of grain refinement as a function of extrusion ratio and compressive deformation is analyzed according to microstructural analysis and different phase identification.