Analysis of Precipitation Hardening of 6061/10% SiC Composite by Differential Scanning Calorimetry

The precipitation of a supersaturated 6061 Al alloy reinforced with 10% SiC_pwas 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 peak-aging temperature and duration also increased. Microstructural examination revealed an increase in grain size when a high solution temperature was applied. To compare predicted peak-aging 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. This revised version was published online in July 2006 with corrections to the Cover Date.