High heat load properties of ultra fine grained tungsten

Ultra fine grained tungsten samples with average grain size of 0.2, 1 and 3 μm were fabricated by resistance sintering under ultra-high pressure. The annealing experiments for the investigation of the material resistance against grain growth showed that recrystallization and grain growth occur obviously at heating temperature of 1500 °C. The finer the initial grain sizes of tungsten, the smaller its grain growth. The effects of transient high heat loads on tungsten surface morphology have been performed in an electron beam test facility with 4 ms pulses at different power density of 0.11, 0.16, 0.22, 0.27 and 0.44 GW/m2, respectively. Particle erosions occurred for tungsten with 3 μm size at 0.16 GW/m2, but for tungsten with 0.2 and 1 μm size at 0.27 GW/m2. The weight losses of tungsten with 0.2, 1 and 3 μm size are 2, 0.1 and 0.6 mg, respectively, at 0.44 GW/m2.