Tungsten heavy alloys

Tungsten heavy alloys (WHA) are gaining increasing attention as potential divertor structural materials in fusion power plants due to their desirable properties such as high strength, ductility, toughness, and low brittle-ductile transition temperature (BDTT) relative to the monolithic tungsten (W). WHA are typically synthesized by liquid-phase sintering (LPS) of elemental tungsten with ductile phase (DP) powders. There are many open questions about WHA divertors and other plasma facing components (PFC). An incomplete list includes: a host of ambient to very high-temperature mechanical properties; the corresponding scourges of irradiation effects; damage driven by prolonged time-dependent high heat flux service; practical operating temperature limits posed by the lower melting temperature of the DP; plasma contamination; radioactive waste limits; fabrication and joining of complex multimaterial components; and accident tolerance and safety risks. Here, we focus on briefly describing the status of current research on WHA, specifically WNiFe, and critically needed future research.