The effect of solid solution treatment parameters on the microstructure and mechanical properties of A286 superalloy

In this investigation, the effects of solution parameters on the microstructure and hardness of a Fe-Ni superalloy were studied. Samples were solutionized in temperature ranges of 900 °C to 1060 °C for the times of 0.5 h to 2.5 h, water quenched and aged at 720 °C for 16 h. for more structural examinations, some solutionized samples were aged at 800 °C and 860 °C for 8 h. The microstructure of the alloy was investigated using optical and scanning electron microscopes and the volume fraction of phases was measured by image analyzer software. The hardness of solutionized and aged specimens and tensile strength of aged samples at room temperature were also assessed. The results showed that hardness and ultimate tensile strength decrease with increasing solution temperature. It was found that increase in the solution temperature led to a decrease in volume fraction of η and carbide phases and an increase in the carbide sizes. It was also found that solution annealing time had no significant effect on the properties of the alloy.