Analysis of precipitation hardening of 6061/10% SiC composite by differential scanning calorimetry

Abstract

The precipitation of a supersaturated 6061 Al alloy reinforced with 30% SiCp was monitored by using a DSC technique. DSC thermal curves were used to predict peak-aging temperatures and durations. The activation energies for precipitation of the β″ phase were found to increase with elevation of the solution temperature from 510 to 600°C, and hence the peakaging temperature and duration also increased. Micro structural examination revealed an increase in grain size when a high solution temperature was applied. To compare predicted peakaging temperatures and durations, hardness measurements were carried out after artificial aging. The studies revealed that peak-aging hardening was obtained when the aging temperatures and durations corresponded to about 95% to 97% precipitation of β″ phase from conversion plots.