Nano Tungsten for Divertor Plates

Tungsten is a primary candidate material for the plasma facing materials for plasma diverting. This research will lead to the development of tungsten plate with extremely fine grain size so as to produce a divertor structure with improved mechanical durability (e. g., crack resistance). Nano-tungsten powder will be processed through microwave synthesis. This powder will be rapidly sintered into testable, bulk material. This material will be evaluated for long-term use in high-energy nuclear plasma through such tests as plasma erosion and heat flux measurement. In Phase I, nanopowders of tungsten were synthesized and then specially consolidated. The resultant material was evaluated for microstructure, which was found to be very fine. Helium irradiation tests were performed which indicated that further study is warranted to address helium bubble formation. Hardness test on the fine microstructure tungsten yielded impressive initial results. The Phase II project will optimize powder synthesis and consolidation. Finer microstructure and 100% density of samples will be targeted along with scale-up of powder synthesis. Purdue University will run evaluation studies on the developed material. Commercial Applications and other Benefits as described by the awardee: All reactors using a tungsten divertor or other plasma-facing component can benefit from the development of this material. In addition, armor-piercing bullets for police use can be made from nano-tungsten material. This work will help to scale up the production of tungsten and its compounds with highly developed nano-microstructure. Nano tungsten carbide can be used, for example, for cutting tools and wear surfaces.