Abstract
Current heat treatment standards do not adequately define tempers for thin-walled castings that solidify at high rates. Emerging casting processes, such as vacuum high-pressure die casting, benefit from rapid solidification rates, which result in fine microstructures and reduce the need for prolonged solution treatment times. Studies on rapidly solidified samples with secondary dendrite arm spacing between 35-10 μm were conducted, with solution times ranging from 30 minutes to 9 hours, and various aging parameters were evaluated. Metallurgical analysis revealed that increased microstructure refinement could reduce solution time by up to 50% without compromising the alloy’s mechanical properties. The highest strengths, with an ultimate tensile strength of 330 MPa (47.9 ksi) and a yield strength of 300 MPa (43.5 ksi), were achieved under T6 peak aging conditions. Additionally, thermal analysis and dilatometer results are presented to evaluate phase dissolution during solution treatment, aging kinetics, and dimensional stability.
