Tensile behavior of single crystal nickel-based superalloys at 650°C

• DOI: 10.1016/j.intermet.2023.107976
• Publication Date: 2023-06-13T05:48:05Z
• Authors: Benoît Mansoz; Luciana Maria Bor...; Jérémy Rame; Caspar Schwalbe; K.V. Vamsi; Pierre Caron; Jonathan Cormier; Florence Pettinar...
• Keywords: Tensile properties; Ni-based single crystal superalloys; Chemical composition; [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci]; Yield stress

The yield strength (YS) of single crystal Ni-based superalloys is a critical factor for low temperature low cyclefatigue and Out-of-phase thermomechanical fatigue durability of turbine blades. The chemical composition ofthis class of alloys appears to have a major role in their low temperature tensile behavior. Indeed, alloying el-ements modify the antiphase boundary (APB) energy of the γ′ phase and so its resistance to shearing. Toinvestigate the influence of the chemical composition on the YS, 18 superalloys of different generations weretensile tested at 650 ◦C. The results show a significant YS evolution of up to 250 MPa between the first generationand the following generations. The YS differences are mainly attributed to the contributions of γʹ which in turn isdependent on the γʹ phase composition. An EDNNB model was adapted to estimate the APB energies for theaforementioned set of alloys using Thermo-Calc data. Ta and Ti elements appear to be the most efficient γ′strengtheners. The higher their content is, the higher the APB energy is and the stronger the alloy is in terms oftensile YS. Several alloys also exhibit an important strain hardening<br/>International audience<br/>