• Gries, Thomas
• Gietl, Hanns
• Neu, Rudolf
• Schwalenberg, Daniel
• Raumann, Leonard
• Riesch, Johann
• Höschen, Till
• Coenen, Jan Willem
• Lau, Alexander
• Mao, Yiran
• Linsmeier, Christian

Abstract

<jats:p>Tungsten-fibre-reinforced tungsten composites (Wf/W) have been in development to overcome the inherent brittleness of tungsten as one of the most promising candidates for the first wall and divertor armour material in a future fusion power plant. As the development of Wf/W continues, the fracture toughness of the composite is one of the main design drivers. In this contribution, the efforts on size upscaling of Wf/W based on Chemical Vapour Deposition (CVD) are shown together with fracture mechanical tests of two different size samples of Wf/W produced by CVD. Three-point bending tests according to American Society for Testing and Materials (ASTM) Norm E399 for brittle materials were used to obtain a first estimation of the toughness. A provisional fracture toughness value of up to 346MPam1/2 was calculated for the as-fabricated material. As the material does not show a brittle fracture in the as-fabricated state, the J-Integral approach based on the ASTM E1820 was additionally applied. A maximum value of the J-integral of 41kJ/m2 (134.8MPam1/2) was determined for the largest samples. Post mortem investigations were employed to detail the active mechanisms and crack propagation.</jats:p>

Topics

• impedance spectroscopy
• crack
• composite
• bending flexural test
• tungsten
• fracture toughness
• chemical vapor deposition