Recent developments toward the use of tungsten as armour material in plasma facing components

Abstract

Future fusion experiments will rely on tungsten armour tile for their plasma facing components. In order to sustain steady state operation, the components need to be cooled through an attachment to a heat sink. All current reference concepts rely on contact bonds, unfavourable for long term application (high temperature service, cycle fatigue, thermal shocks). Three routes toward the development of thick tungsten bonds are presented here, namely functionally graded tungsten copper assembly, electron beam welding of tungsten, and coating processes. All present favourable prospects, and tend to indicate that a thick bond is possible with tungsten. Dedicated programs as well as industrial implication are however required if such concepts are to be used actually for the fabrication of large components series.

Efficiency and availability driven R&D issues for DEMO

“…Materials with functional gradient could be an elegant solution. Recent developments of functionally graded W Cu assembly are encouraging [66]. This type of development is further carried out towards functionally graded W-EUROFER in parallel to brazing development for application to the He-cooled divertor.…”

W–steel and W–WC–steel composites and FGMs produced by hot pressing

“…The plasma facing parts ("armor") are to be joined to a cooling system or support structure, made from copper-based alloys and stainless steel, respectively. For a fusion reactor device, tungsten is foreseen as the main plasma facing material, to be joined to reduced activation stainless steel as a heat sink and construction material [3,4]. When two or more materials are to be used, several joining issues come into play.…”

Prestress design of stainless steel fibers/zirconia composite by tape casting

“…Ballistic resistant material is one of the research hotspot about armor technology by rapid development of weapon power and anti-amour weapons [1] . Armor materials require not only excellent anti-penetration property but also lower density and high specific strength [2,3] .…”