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In future fusion reactors, tungsten is the prime candidate material for the plasma facing components. Nevertheless, tungsten is prone to develop cracks due to its intrinsic brittleness-a major concern under the extreme conditions of fusion environment. To overcome this drawback, tungsten fiber reinforced tungsten (W f /W) composites are being developed. These composite materials rely on an extrinsic toughing principle, similar to those in ceramic matrix composite, using internal energy dissipation mechanisms, such as crack bridging and fiber pull-out, during crack propagation. This can help W f /W to facilitate a pseudo-ductile behavior and allows an elevated damage resilience compared to pure W. For pseudo-ductility mechanisms to occur, the interface between the fiber and matrix is crucial. Recent developments in the area of powder-metallurgical W f /W are presented. Two consolidation methods are compared. Field assisted sintering technology (FAST) and hot isostatic pressing (HIP) are chosen to manufacture the Wf/W composites. Initial mechanical

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No abstract

In future fusion reactors, tungsten is considered as the main candidate material for plasma-facing components. However, the intrinsic brittleness of tungsten is of great concern during operation. To overcome this drawback, tungsten fiber-reinforced tungsten composites (Wf/W) are being 2 developed relying on extrinsic toughening principles. Tungsten (W) fibers with extremely high tensile strength and ductility are used to reinforce a tungsten matrix. In this work, field assisted sintering technology (FAST) is used to produce Wf/W material. Mechanical characterizations including Charpy impact and 3-point bending tests are performed. Based on the 3-point bending test results, the Wf/W materials can facilitate a promising pseudoductile behavior even at room temperature, similar to fiber reinforced ceramic composites. Fracture energy density and fracture toughness together with the crack-resistance curves (R-curves) are measured. Compared to conventional pure tungsten, Wf/W shows significant improvement in fracture toughness.