Computational Materials Design of Tungsten Alloys with Improved Fracture Toughness and a Lowered Ductile to Brittle Transition Temperature (DBTT)

The development of a reliable and safe fusion energy source will require advances in a number of technological areas, including high temperature materials with good mechanical properties that are also resistant to radiation embrittlement. Because tungsten has the highest melting point (3410C) and lowest vapor pressure (1.3x10-7 Pa at TMelt) of all metals, tungsten and its alloys are attractive candidate materials for use in high temperature applications. However, the use of tungsten and tungsten alloys is currently limited by their high ductile-brittle transition temperature and relatively low ductility and fracture toughness. QuesTek Innovations LLC, a leader in the field of computational materials design, proposes under this SBIR program to implement a systems- based approach to design and develop novel cost-effective tungsten alloys with improved toughness and a suppressed DBTT for plasma-facing components in future fusion reactors. QuesTek will investigate and assess a number of microstructural concepts and use our proprietary computational models to design novel new compositions. QuesTek will have prototype ingots manufactured to demonstrate that the new tungsten alloys have improved fracture toughness and DBTT properties. Commercial Applications and Other Benefits: The primary intended application is plasma- facing components of commercial fusion energy plants, such as the first wall blanket and divertor assembly in the ITER facility and future fusion energy plants. Other potential applications for improved high-toughness, ductile tungsten alloys may include rocket engines, rotating intertia members, x-ray targets, radiation shields, downhole well logging casings, cutting tools, warhead penetrators, and weight balances for rotor blades. QuesTek may commercialize its novel tungsten alloys by licensing intellectual property to alloy producers.