Ductile Tungsten Alloy using Low-Activation Alloying Elements

Designs for the International Thermonuclear Experimental Reactor (ITER) employ several plasma-facing materials selected for their suitability to regions of the vessel with different power and flux characteristics. Tungsten is one of the most important candidates for diverter component materials, given its low erosion and good mechanical properties at high temperature. However, high-toughness tungsten alloys that are suitable for fusion plasma environments still must be developed to overcome the inherently brittle nature of tungsten. Ultramet will develop solid solution alloys of tungsten-iron with relatively high toughness and ductility using chemical vapor deposition (CVD) processing that has recently been demonstrated for fission fuel cladding. The process will allow the direct deposition of solid solution alloys to produce complex net-shaped plasma-facing components of the desired tungsten alloys, without the high impurity levels, porosity, complexity, and cost associated with alternative processing such as melting, sintering of powders, or homogenization heat treatments. Commercial applications and other benefits: Nuclear fusion is an ideal alternative to increasingly scarce and expensive fossil fuels and can provide a much greater quantity of environmentally sound energy than wind, solar, and geothermal sources. Practical application of fusion for efficient electricity generation requires the development of materials and structures that can withstand the demanding reactor environment. The proposed tungsten alloys are key materials for reactors that will ultimately be scaled up for commercial use.