E.Y. Chen, C.C. Chen
Transition45 Technologies, Inc,
Keywords: Tungsten, Deformation, Producibility, Fusion, Hypersonics
Summary:A novel manufacturing process to tailor the bulk microstructure-properties of important structural materials as tungsten and its alloys has been demonstrated. Tungsten, with its many unique characteristics, plays an important role in diverse aerospace, defense, and commercial applications including for rocket propulsion, munitions, fusion reactors, and even semiconductor manufacturing. The refractory metal, however, continues to possess shortcomings that must be addressed in order to reach its potential as a structural material. These include a high ductile-to-brittle transition temperature, low ductility and poor fracture toughness, low machinability and fabricability, low-temperature brittleness, radiation-induced brittleness, and a relatively low recrystallization (RX) temperature compared to its operation temperature. Past efforts to increase the ductility of bulk tungsten have been mostly directed at alloying, grain refinement, extreme working, area reductions, impurity reductions, and heat treatments. The innovation here incorporates a competitive process between straining, dynamic softening, and/or dynamic RX during deformation. Through close control of thermo-mechanical processing variables, microstructural and grain flow control is achieved resulting in final products with better strength, ductility, durability, fabricability/joinability, and inspectability. While transferable to most important structural materials, the technology is most invaluable when applied to relatively low workability materials prone to cracking during processing.