Application of rapid heating methods for the thermal processing of aluminum alloy forgings is investigated in this work. Differential scanning calorimeter analysis of rapid heating of wrought aluminum alloys and laboratory simulation of solution treatment of wrought aluminum alloys were performed. The results showed that rapid heating accelerated the solutionizing of second phases in the alloys. Based on the results of these studies and practical limitation at the shop floor, optimized thermal processing cycles with an infrared furnace for AA 2618 and AA 6061 forgings were determined. Prototype forgings were produced and thermally processed with the proposed infrared heating cycles in addition to prototype forgings processed with conventional heat treatment.
Mechanical testing was performed from samples obtained from the prototype forgings and measured mechanical properties were compared to understand the effect of thermal processing for shorter duration with rapid infrared heating. The results showed that short solution treatment with rapid infrared heating can produce forgings with mechanical properties comparable to that of conventionally processed forgings.
The energy savings resulting from the short solution treatment with rapid infrared heating are also analyzed. The acceleration of the dissolution of second phase particles with rapid infrared heating has been attributed to the thermal stresses arising from mismatch of thermal expansions of the aluminum matrix and the second phases during rapid heating.