Effect of heat treatment temperature on the microstructure and properties of high Ti/Al ratio nickel-based superalloys fabricated by laser powder bed fusion

In this study, high Ti/Al ratio (2.35) nickel-based superalloys were successfully fabricated using the laser powder bed fusion (LPBF) technique and systematically investigated how varying heat treatment temperatures influence the alloy's microstructure and mechanical properties. The findings indicate that the high Ti/Al ratio alloy possesses promising printability. At a solid solution temperature of 1180 °C and an aging temperature of 830 °C, the alloy demonstrates an optimal balance of strength and plasticity. This is attributed to the highest degree of recrystallization, the absence of harmful phase precipitation, and a uniform distribution of the γ′ phase. Moreover, a solid solution temperature of 1120 °C leads to η phase precipitation, significantly decreasing the alloy's plasticity. This study not only elucidates the mechanism by which heat treatment temperature affects the structural evolution of high Ti/Al ratio nickel-based superalloys but also offers theoretical support and practical guidance for superalloy material design and future applications. • Achieved good printability for high Ti/Al ratio (2.35) nickel-based superalloys via LPBF, balancing mechanical properties and printability. • Identified optimal heat treatment (1180 °C solution treatment and 830 °C aging), maximizing strength and plasticity with no η phase precipitation. • The alloy exhibits superior mechanical properties over a wide temperature range, outperforming several commercially available LPBF-processed superalloys.