The development of a materials innovation infrastructure (MII) that will enable rapid and significant reductions in the development time for new materials with improved properties is a critical element of the Materials Genome Initiative (MGI). Within this infrastructure materials data and modeling tools will be integrated to optimize material properties for a given set of design criteria. Case studies will be used to determine which data structure and tools need to be implemented to facilitate efficient advanced materials design and establish standards for the MII. This project highlights a materials design approach to the design of a high temperature cobalt-based superalloys for the aerospace and power generation industries.
Currently in the aerospace industry it takes approximately 18 months to design a part, but it can take over 10 years to design the ideal material from which to make the designed part. The goal of this project is to dramatically reduce the time to design a new material for a specific application. For the specific case study of a new class of γ/γ´ Cobalt-based superalloys, the two most important design criteria are:
- Increased homologous operating temperature (> 50 degrees higher that current Ni-based superalloys), which will increase the turbine engine efficiency and thus decrease fuel consumption and emissions.
- Increased wear resistance, which will increase the service life of the engine and lower operational costs.
The advanced materials design approach for a new class of γ/γ´ Co-based superalloys is predicated on establishing the essential processing-structure-property links that are imperative for optimizing the materials chemistry and processing parameters to achieve desired materials performance objectives. Essential to this effort is the development of composition and temperature dependent functions to describe the properties of these multicomponent, multiphase materials. Composition and temperature dependent descriptions of thermodynamics, diffusion mobility, and molar volumes to describe the Co-Al-W-X (where X = Ni, Ta, Ti, Re) composition space are being developed. These composition and temperature descriptions are based on experimental and first principles data. The descriptions will be used as input into mechanistic models to predict critical material properties, including high temperature strength and creep resistance. These predictions will be verified by experiments and, if needed, the results will be used for further refinement of the databases and tools. Ultimately, these predictive models will enable determination of an alloy composition and corresponding processing and heat-treatment needed it to achieve the optimal microstructural stability, creep and wear resistance.