Textile preforms for tungsten fibre-reinforced composites

摘要

Demanding high heat flux applications, as for example plasma-facing components of future nuclear fusion devices, ask for the development of advanced materials. For such components, copper alloys are currently regarded as heat sink materials while monolithic tungsten is foreseen as directly plasma-facing material. However, the combination of these materials in one component is problematic since they exhibit different thermomechanical characteristics and their optimum operating temperatures do not overlap. In this context, an improvement can be achieved by applying composite materials that make use of drawn tungsten fibres as reinforcement. For the manufacturing processes of these composites, suitable tungsten fibre preform production methods are needed. In the following, we will show that tungsten fibres can be processed to suitable preforms by means of well-established textile techniques as studies regarding the production of planar weavings (wire distances of 90-271 mu m), circular braidings (multilayered braidings with braiding angle of 60 degrees and 12 degrees) as well as multifilamentary yarns (15 tungsten filaments with 16 mu m diameter) are presented. With such different textile preforms tungsten fibre-reinforced tungsten (W-f/W) with a density of over 99% and pore-free tungsten fibre-reinforced copper W-f/Cu composites were produced which proves their applicability with respect to a composite material production processes.