Microstructure and Properties of Tungsten Rhenium Alloy Prepared by Laser Sintering

Tungsten alloy with addition of rhenium and tantalum was prepared by laser sintering. Microstructure and properties of the samples were tested by optical microscope, X-ray diffractometer and microhardness tester. Dense tungsten alloy block materials were prepared by adjusting laser beam power and laser spot scanning speed. The oxidation of powder can be avoided by desorption and deoxygenation pretreatment and inert gas protection. Static recrystallization occurred in the laser sintering process. In the core of the sample, equiaxed grains significantly larger than the powder particles were formed. In the edge of the sample, where the temperature was lower than the core due to heat dissipation, small and immature equiaxed grains whose size was close to the particle size of the powder were formed. The addition of tantalum and rhenium formed a solid solution in tungsten. Because of the effect of solid solution atoms to the lattice, with the increase of the addition of tantalum and rhenium, the density of samples decreased, while the microhardness increased accordingly.