Microstructure and mechanical properties of tungsten composite reinforced by fibre network

摘要

In this paper the tungsten-fibre-net-reinforced tungsten composites were produced by spark plasma sintering (SPS) using fine W powders and commercial tungsten fibres.The relative density of the samples is above 95％.It was found that the recrystallization area in the fibres became bigger with increasing sintering temperature and pressure.The tungsten grains of fibres kept stable when sintered at 1350℃/16 kN while grown up when sintered at 1800℃/16 kN.The composite sintered at 1350℃/16 kN have a Vickers-hardness of～610 HV,about 2 times that of the 1800℃/16 kN sintered one.Tensile tests imply that the temperature at which the composites (1350℃/16 kN) begin to exhibit plastic deformation is about 200℃-250℃,which is 400℃ lower than that of SPSed pure W.The tensile fracture surfaces show that the increasing fracture ductility comes from pull-out,interface debonding and fracture of fibres.