Effect of La2O3 addition on the synthesis of tungsten nanopowder via combustion-based method

In this study, the influences of LaOadded on the phase, morphology and reduction process of tungsten oxide prepared by solution combustion synthesis(SCS) were investigated for the first time. And tungsten nanopowders with different LaOdoping amount(0.5～5.0 wt%) were successfully prepared by SCS and followed hydrogen reduction. The results showed that with the increase of LaOaddition,the product synthesized by SCS changed from needle-like WOto irregularly granulated H0.53 WO3 and the complete reduction temperature also increased form 700°C to 850°C. The densification behavior of as-prepared W nanopowders revealed that the densification inhibitory effect of LaOwas enhanced as the LaOaddition increased. Nevertheless, due to the optimal size and distribution of LaOparticles,the sample with 2.0 wt% LaOaddition has a smallest grain size of 0.47 μm and a highest microhardness value of 739.3 Hv0.2, which are the best compared with the literature.