Study on microstructure and properties of tungsten alloy prepared by laser sintering

The tantalum and rhenium doped tungsten-based alloys were prepared by laser sintering, and the microstructure and mechanical properties of the tungsten-based alloy samples were investigated by scanning electron microscope (SEM), optical microscope (OM), X-ray diffraction (XRD), and micro-hardness tester. The results show that, the laser power and laser scanning speed are the important factors affecting the relative density of tungsten alloy blocks, the compact tungsten alloy block materials are obtained by optimizing the parameters. The powder oxidation is avoided by the desorption and deoxygenation pretreatment and the inert gas protection. The microstructures show that, the static recrystallization occurs in the laser sintering process. The equiaxial grains with the significantly larger size than the powder grains are formed at the core of the tungsten-based alloy sample, and the equiaxial grains with the size slightly larger than the powder grains size are formed at the edge of the tungsten-based alloy sample. The XRD results show that, the doped tantalum element exists as the solid dissolved atoms in tungsten matrix. The performance testing results show that, the density decreases with the increase of tantalum, but the microhardness increases.