Probabilistic Prediction of Location-Specific Microstructure in Turbine Disks Navy STTR FY2010.A Sol No.: Navy STTR FY2010.A Topic No.: N10A-T028 Topic Title: Probabilistic Prediction of Location-Specific Microstructure in Turbine Disks Proposal No.: N10A-028-0028 Firm: Symplectic Engineering Corporation 2901 Benvenue Ave. Berkeley, California 94705-2209 Contact: Shmuel Weissman Phone: (510) 528-1251 Web Site: www.symplectic.com Abstract: Turbine efficiency improves with increased operating temperature. Consequently, the rim zone of disks operates at high temperatures where creep is the main concern. The bore and web zones operate at lower temperatures, where strength is the driving design criterion. Procedures to produce disks that can meet both demands include dual heat-treatment and hybrid disks. A thin transition zone forms in disks produced with either of these technologies, which is characterized by location-specific three-dimensional microstructure and residual bulk stresses. The objective of this project is to enable the optimization of advanced nickel-base superalloy turbine disks by developing probabilistic modeling and simulation methods to predict location-specific microstructure and bulk residual stresses. Symplectic Engineering is proposing to develop a multi-scale model to meet this objective. The global (disk) scale will be represented as a coupled thermal-mechanical system, approximated by a three-dimensional finite elements model. A number of models will be combined to produce the local-scale representation including gamma-prime coarsening and grain growth. The two scales will interact independently at each Gauss point of the global-scale finite element mesh. The performance of the proposed model will be demonstrated by simulating the forging of a dual heat-treated disk, and contrasting the prediction with experimental data. Benefits: The outcome of this project will be software to predict the microstructure and bulk residual stress in advanced nickel-based supperalloy disks. Advanced turbine disks feature two microstructures to address the different operating conditions at the rim vs. bore and web zones. Two types of disk are available to meet this need: dual heat-treated and hybrid. This software developed in this project will permit the optimization the manufacturing process to better control the transition zone that forms between the two desired microstructures. Moreover, it will permit predictions, early in the development cycle, of the performance of disks. These predictions will give disk designers a higher degree of comfort when applying aggressive optimization. Advanced gas turbines are used in jet engines for both civil and military applications. Gas turbines are used for electrical power including for renewable energy. In all these cases, the demand for high turbine efficiency leads to high operating temperatures, where dual-microstructure disks are required. The software product resulting from this project is addressed precisely at these advanced disks. Symplectic Engineering will commercialize the software to all these markets. Return