Spark plasma sintering of wire exploded tungsten nano-powder

Mechanical and thermodynamic measurements are reported for specimens spark plasma sintered from tungsten nano-powder. A maximum Vickers hardness of 3.31±0.03 GPa, at a relative density of 0.98 was achieved at sintering temperature of 1,800°C and above. This corresponds to the value of hardness for bulk tungsten. Grain size analysis indicated a grain growth activation energy of 160±10% KJ/mol. Sintering temperatures were found to be as much as 270°C lower than previously reported. During the Spark Plasma Sintering (SPS), a reduction in the amount of tungsten oxide was observed, especially at temperatures above 1,500°C. A number of mechanisms are thought to be responsible including the SPS induced decomposition of the oxide into metallic tungsten.

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