Microstructure and mechanical properties of Wf/W composites influenced by Y2O3 coating

Tungsten fiber reinforced tungsten (Wf/W) composite is one of the candidates to improve the toughness of tungsten materials. Powder metallurgy is a potential method to produce Wf/W composites, but it may cause the recrystallization and grain growth of the reinforcing fibers during the high temperature sintering process. In the present work, a layer of Y2O3 is coated on the fiber surface by magnetron sputtering to protect the fibers and prevent recrystallization and abnormal growth of grains. Wf/W composites with and without Y2O3 coating were fabricated by a field assisted sintering technology (FAST) process. Microstructure and mechanical properties were characterized. The influence of the Y2O3 coating on the properties of the fiber was discussed in detail. The Y2O3 coating can effectively prevent recrystallization and abnormal grain growth of fibers during the sintering process. The Wf/W composites with Y2O3 coating shows higher strength and pseudo-ductile behavior.