W_0.5TaTiVCr-based composite reinforced with W-mesh for fusion plasma-facing applications

Abstract

We present research into tungsten (W) alloy-based composites reinforced with a W-mesh. Due to low activation and higher strength properties, W 0.5 TaTiVCr was used as a matrix material. Layers of W-mesh (W mesh ) were embedded in W 0.5 TaTiVCr for improving ductility and toughness. We employed elemental powder mixing and spark plasma sintering (SPS) at 1600 • C for sample preparation, which is a simpler method as compared to chemical vapor infiltration and hot isostatic pressing. The microstructural analysis shows a W-mesh that is well-bonded with the W 0.5 TaTiVCr matrix, which exhibits multiple phases and a BCC structure. The room temperature compressive fracture strain of W 0.5 TaTiVCr/W mesh composites show an improvement from ~3.5% to ~15.8% due to increase in W mesh concentration from 10 wt% to 50 wt%, whereas the compressive yield strength changes from ~1900 MPa to ~1700 MPa (at room temperature) and ~1200 MPa to ~950 MPa (at 1200 • C). The W 0.5 TaTiVCr matrix alone shows ~7.7 MPa m 1/2 fracture strain, and the addition of 10 wt%W mesh in W 0.5 TaTiVCr results in more than a two-fold increase in fracture toughness (up to ~20 MPa m 1/2 ), which suggests a potential use of this material in fusion reactors.