Application of ultrafine metal powder injection moulding on tungsten components in fusion devices

Metal injection moulding (MIM) technology used for ultrafine pure W powders and rare earth oxides dispersion strengthened-W (ODS-W) powders was investigated, including ultrafine powders preparation, feedstock preparation, injection molding technology, sintering technology, and hot isostatic pressing treatment. This technology was applied to manufacture the tungsten components in fusion devices. Microstructures and thermodynamic performances of the tungsten components prepared by this ultrafine metal powder injection moulding technology were analyzed. The results show that, the MIM tungsten components used with ultrafine pure W powders (MIM-W) can achieve the relative density more than 98%, the average grain size is about 10~15 μm, and the thermal conductivity (above 500℃) of MIM-W is close to that of the wrought tungsten components. The MIM tungsten components used with rare earth oxides dispersion strengthened-W powders (MIM-ODS-W) can achieve the relative density more than 99%, the average grain size is 3~5 μm, and the thermal shock resistance of MIM-ODS-W shows excellent.