Aging behaviour of AA6061/SiCp composites produced by direct extrusion with a reversibly rotating die method

Abstract

This paper discusses the influence of thermal treatment parameters on mechanical properties of AA6061+x% vol. SiCp (x = 0, 2.5, 5, 7.5, 10) composites. The composites were consolidated via powder metallurgy processing using the unconventional method of extrusion (the KoBo method). In order to establish the optimum parameters of the heat treatment two different temperatures of supersaturation (530 and 558 °C) were applied. The aging curves were determined at various aging temperatures such as 140, 160, 180 and 200 °C. The effects of applied parameters were studied using the microstructure observations and hardness measurements. Obtained results show that the solution treatment at 530 °C is sufficient to complete dissolution of the precipitates. Higher temperature of the process resulted in accelerating the aged-hardening. The suitable age treating parameters for the AA6061-5 vol. % SiCp composites were 160 - 180 °C for 12 - 16 hours.