Spark plasma and microwave sintering of Al6061 and Al2124 alloys

Abstract

Despite the importance of aluminum alloys as candidate materials for applications in aerospace and automotive industries, very little work has been published on spark plasma and microwave processing of aluminum alloys. In the present work, the possibility was explored to process Al2124 and Al6061 alloys by spark plasma and microwave sintering techniques, and the microstructures and properties were compared. The alloys were sintered for 20 min at 400, 450, and 500°C. It is found that compared to microwave sintering, spark plasma sintering is an effective way to obtain homogenous, dense, and hard alloys. Fully dense (100%) Al6061 and Al2124 alloys were obtained by spark plasma sintering for 20 min at 450 and 500°C, respectively. Maximum relative densities were achieved for Al6061 (92.52%) and Al2124 (93.52%) alloys by microwave sintering at 500°C for 20 min. The Vickers microhardness of spark plasma sintered samples increases with the increase of sintering temperature from 400 to 500°C, and reaches the values of Hv 70.16 and Hv 117.10 for Al6061 and Al2124 alloys, respectively. For microwave sintered samples, the microhardness increases with the increase of sintering temperature from 400 to 450°C, and then decreases with the further increase of sintering temperature to 500°C.