Integrated Computational Design of Three-Phase Mo–Si–B Alloy Turbine Blade for High-Temperature Aerospace Applications

The efficiencies of jet turbine engines are limited in part by the high-temperature properties of Ni-based superalloys utilized within turbine blades. Although Mo–Si–B alloys exhibit promising high-temperature properties, traditional materials development approaches relying extensively upon costly trial-and-error experiments inhibit the adoption rate of new materials. The present research seeks to address this problem by developing and demonstrating a computational materials design framework for the design of Mo-Si-B alloys for gas turbine blade applications. The developed framework utilizes: (1) finite element simulations of 280 random microstructure instantiations to predict microstructure- and temperature-dependent yield strength and fracture toughness and their uncertainties; (2) analytical models to predict stresses due to turbine blade rotation; and (3) the inductive design exploration method (IDEM) to determine robust feasible domains of input and intermediate design variables. IDEM considers three input design variables (i.e., operating temperatures of 1273 K and 1473 K, volume fraction of the Molybdenum solid solution phase 0.45 ≤ v_MoSS ≤ 0.75, and volume fraction of T2 intermetallic phase 0.125 ≤ v_T2 ≤ 0.275) and three intermediate design variables (i.e., yield strength, fracture toughness, and density). Results indicate a maximum feasible temperature of approximately 1295 K at v_MoSS and v_T2 of approximately 0.45 and 0.18, respectively. This work is significant in that it demonstrates the design of Mo-Si-B alloys for high-temperature blades for aerospace applications, thus providing a means to increase efficiencies and reduce greenhouse gas emissions.