Advanced manufacturing applied to nuclear fusion—challenges and solutions

Abstract

Materials needed to achieve designed performance will require formulations and processing methods capable of delivering a compendium of metallic, ceramic and cermet chemistries, which must be finely tuned at source, and tolerant to down-stream thermomechanical adjustment. Structural steels and cermets are continuously being developed by researchers using computational thermodynamics modelling and modified thermomechanical treatments, with oxide dispersion strengthened steel (ODS)-reduced activated ferritic-martensitic steel (RAFM) steels based on 8%–16% wt.% Cr now being assessed. The combination of SiCf and CuCrZr as a metal matrix composite containing an active coolant would be seen as a major opportunity, furthermore, composite ceramic materials consisting of SiC fibres reinforcing a SiC matrix capable of being joined to metallic structures offer great potential in the development of advanced heat exchangers. Continuing the theme of advanced manufacturing, the use of solid-state processing technologies involving powder metallurgy–hot isostatic pressing and spark plasma sintering to produce near-net shaped products in metallics, ceramics and cermets are critical manufacturing research themes. Additive manufacturing (AM) to produce metallic and ceramic components is now becoming a feasible manufacturing route, and through the combination of AM and subtractive machining, capability exists to produce efficient fluid carrying structures that could not be manufactured by any other process. Extending this to using electron beam welding and advanced heat treatments to improve homogeneity and provide modularity, a two-pronged solution is now available to improve capability and integrity, whilst concurrently offering increased degrees of freedom for designers.