Thermal studies have been carried out on a series of particulate (SiC and Al2O3) reinforced 6061 Al metal matrix composites. Differential scanning calorimetry and dynamic mechanical analysis have provided information on the formation/dissolution of precipitate phase(s) and the effect of temperature on the short-term storage modulus of the materials, respectively. These studies were also used to identify the phase changes responsible for the maximum damping properties of the materials.