Combined hot isostatic pressing and heat treatment of aluminum A356 cast alloys

The mechanical and microstructural properties of aluminum A356 cast alloy are investigated as a function of hot isostatic pressing and heat treatment parameters. The combined hot isostatic pressing and heat treatment process leads to an improvement of mechanical properties when compared to regular hot isostatic pressing with no separate heat treatment. An oversaturated state with magnesium and silicon atoms dissolved in the aluminum matrix can be achieved by increasing the quenching rate to 6.9 K/s within the temperature range between 813 K and 473 K. Aging can be performed directly after hot isostatic pressing, without the necessity of a separate solution annealing step. Thereby, the overall processing costs could be reduced.