Microstructure characterization and properties of YSZ particles doped tungsten alloy prepared by liquid phase method

In this paper, Yttria-stabilized zirconia reinforced tungsten alloys (W-YSZ) were prepared by liquid phase method combined with powder metallurgy technology, aiming at optimizing the powder quality and improving the properties of tungsten alloy. In the process of hydrothermal synthesis, ZrO2 with various crystal structures can be prepared by controlling the ratio of ZrO2 to Y2O3. When the doping mass ratio of ZrO2 and Y2O3 is 4:1, ZrO2 can be stabilized to form cubic phase structure. ZrO2 and excessively doped Y2O3 in the composite powders can refine the particle size of tungsten particles and reduce the degree of agglomeration. Compared with SPS sintered samples, the size of the samples sintered by vertical melting is coarser, but because of the low sintering temperature of SPS, the density is lower, while the density and hardness of the samples sintered by vertical melting are higher. After sintering at high temperature, the zirconia did not undergo crystal transformation, but remained cubic phase. The (110) of W and (002) of YSZ have a semi-coherent relationship, and the mismatch rate is 12% according to calculation, with good interface bonding and no obvious cracks. Due to the doping of YSZ particles, the strength and toughness of the tungsten alloy are enhanced by the combined effect of dispersion strengthening and fine grain strengthening.