Currently there is a high level of interest in the studies on age-hardening kinetics of aluminium alloys containing discontinuous reinforcements. It is now well established that the presence of particulate reinforcements like SiC, $A1_20_3$ or $B_4C$ in aluminium alloys significantly alter their response to aging treatment. Studies to date indicate that the change in the degree of response depends on (a) composition of the matrix alloy [1-5], (b) nature of reinforcement including its surface composition, [6-8] (c) volume fraction of reinforcement [9] and (d) method used in the fabrication of the composite [10-11]. 6061 aluminium alloy matrix composites reinforced with particles or whiskers of SiC undergo accelerated aging compared to the unreinforced alloy [1,3].