Micro- and macro- elastic properties of tungsten fiber-reinforced tungsten composites probed by nano-indentation and laser ultrasonics

Abstract

The elastic properties of tungsten fiber-reinforced tungsten composites (Wf/W) were characterized on the micro- and macro- scale by combined nano-indentation and laser ultrasonic measurements, respectively. Wf/W composite materials are currently being developed as advanced tungsten (W) plasma facing materials for fusion devices. They possess pseudo-ductility and can overcome some of the limitations caused by the inherent brittleness of pure-W at lower temperatures. The Young's modulus was determined by nano-indentation hardness measurements of the W-matrix and W-fibers separately. The values were combined by simple rule of mixture, and compared to bulk values obtained from laser ultrasonics measurements. The results show that the simple rule of mixtures is valid up to 50% fiber volume fractions.