The investigation of Y doping content effect on the microstructure and microhardness of tungsten materials

In this study, the microstructure and microhardness of tungsten-yttrium (W-Y) composites were investigated as a function of Y doping content (0.25-3 wt%). It was found that the crystallite sizes and the powder particle sizes were increased as a result of the increase of Y content. Nearly fully dense materials were obtained for W-Y alloys when the Y content was higher than 0.5 wt%. The EDS analysis revealed that the Y rich phases were complex (W-Y) oxides formed during the sintering process. The Y doping content showed obvious influence on the refinement of tungsten grains during sintering. W-1.5Y composite showed the finest microstructure with an average grain size of 0.32 μm, and thus achieved the highest Vickers microhardness with the value of 770 HV0.2.