Spark Plasma Sintering of Al6061 and Al2124 Alloys

Abstract

Recently spark plasma sintering has been proven to be effective non-traditional powder metallurgy technique to sinter fully dense materials in short sintering times at relatively low sintering temperatures and without a binder or pre-compaction step. Despite the importance of aluminum based alloys as candidate materials for applications in aerospace and automotive industries because of their light weight, very little work was dedicated to spark plasma processing of these materials. In this work we explored the possibility to process Al2124 and Al6061 alloys using spark plasma sintering technique. The sample were sintered for 20 minutes at 400, 450 and 500°C using fully automated FCT system spark plasma sintering equipment. A scanning electron microscope was used to analyze the microstructure of sintered samples. The density and Vickers microhardness of the sintered samples were measured using an electronic densimeter and a digital microhardness tester respectively. The hardness and density of the spark plasma sintered samples were reported as a function of sintering temperature. It was found that full density (100 % of the theoretical density) was achieved with sintering for 20 minutes at 450°C for Al6061 alloy and at 500°C for Al2124 alloy. The density and microhardness of the sintered samples increased with the increase of sintering temperature.