Development and Properties of Tungsten-Based Coatings Sprayed by WSP(R)

Plasma sprayed tungsten and tungsten-copper coatings are being developed for potential application as plasma facing materials for fusion reactors. Initial spray tests indicated difficulties in tungsten melting and in-flight oxidation. Numerical modeling was performed to help explain these issues. A complex study of the process and its products was performed, including: in-flight diagnostics, characterization of isolated splats, and structure, composition, thermal and mechanical properties of the coatings. Based on these results, the process was optimized, with respect to powder size and various spraying parameters, to improve melting of the particles, reduce oxidation and increase the deposition efficiency.