Densification behavior and performance of La₂O₃-doped W nanopowders

The La₂O₃-doped W nanopowders were prepared by the solution combustion synthesis method. The densification behavior of the La₂O₃-doped W nanopowders and the effect of La₂O₃ on the densification of the W nanopowders were analysed. Meanwhile, the microstructure, thermal conductivity, and microhardness of the sintered alloys were also studied. The results show that, La₂O₃ can significantly inhibit the densification rate of W nanopowders. The relative density of the pure W powders sintered at 1350 ℃ can reach 96.2%, while that of the La₂O₃-doped W nanopowders sintered at 1500 ℃ is only 95.0%. The grain size of the La₂O₃-doped W alloys sintered at 1500 ℃ is 0.57 μm, which is one order of magnitude smaller than that of the pure W alloys. Therefore, the thermal conductivity of the La₂O₃-doped W alloys is lower than that of the pure W alloys, but the microhardness is significantly improved.