Electric Erosion Induced Microstructure and Mechanical Properties in Spark Plasma Sintered Al-4.5 wt. % Cu Alloy

Abstract

Abstract The Al-4.5 wt.% Cu powder was compacted by spark plasma sintering at three compaction pressures namely 30, 40, and 50 MPa maintaining temperature constant at 500°C. Porosity seems to be closed in all the 3 cases. Relative density of S-50 is decreased due to increase in electrical erosion holes. Transmission electron microscopy studies reveal the presence of dislocations in all the compacts and shear bands observed only in the compact sintered at 50 MPa. A power law creep mechanism involving dislocations is found to be observed in all the compacts sintered at all pressures, which is evident from the TEM micrographs as well. The dissolution of Al2Cu precipitates in the aluminum matrix, and the increase in electric erosion holes were noticed with increase in pressure from 30 to 50 MPa. The decrease in the volume fraction of Al2Cu phase and the increase in the formation of electric erosion holes resulted in reduced hardness and compression strengths of the compacts.