Microstructures and Tensile Mechanical Properties of Consolidated Copper

Abstract

Two consolidated copper samples were prepared by consolidation of a gas atomized powder using two different routes of spark plasma sintering (SPS), respectively. The first route was direct SPS of copper powder at 800 °C for 10 minutes, and the second route was compacting copper powder by die-pressing to produce a powder compact followed by SPS of the powder compact at 800 °C for 10 minutes. The microstructures and tensile mechanical properties and the fracture surfaces of specimens have been studied. It was found that the level of consolidation of the sample made using Route 1 was higher than that of the sample made using Route 2, as reflected by the relatively higher strength and better ductility of the first sample than those of the second sample. The lower consolidation level of the second sample was depicted by the higher volume fraction of cavities in the fracture surfaces of specimens which were formed by separation of the powder particles at the weakly bonded interparticle boundaries. The grain sizes of the first sample were larger than those of the second sample. The reasons for the differences in the levels of consolidation and grain sizes associated with two SPS routes are discussed.