Tensile deformation behavior of tungsten fibre-reinforced tungsten composite specimens in as-fabricated state

To overcome the inherent brittleness of tungsten, which is a promising candidate for a plasma-facing material in a future fusion device, tungsten fibre-reinforced tungsten composites (W_f/W) have been developed. As a part of the materials characterisation program on W_f/W, we present the results of first tensile tests of as-fabricated W_f/W in this contribution. The results give insight on the ultimate tensile strength properties and reveal the active toughening mechanisms under tension load within the composite. Fibre bridging, fibre necking as well as fibre pull out were observed. This is leading to the typical pseudo ductile behavior of the composite which is characterized by a rising load bearing capability despite multiple matrix cracks accompanied by non catastrophic crack propagation (in the matrix). The description of the mechanical tests is supplemented by detailed microstructural investigations.