Selective Laser Melting of Tungsten-Rhenium Alloys

Additively manufactured tungsten-rhenium alloys have been compared with pure tungsten in terms of their volumetric density, cracking behavior, microstructure, and hardness. The compositions W-5 wt.%Re and W-25 wt.%Re were explored. Increasing the rhenium content led to an increasing percentage of the theoretical density, with a maximum of 97.6% achieved with 25 wt.% Re. The characteristic cracking behavior of pure tungsten was greatly mitigated for the W-25%Re composition. Electron backscatter diffraction revealed the effect of rhenium in both reducing the average grain size and leading to a more equiaxed grain geometry. Postprocessing heat treatments were explored to heal remaining cracks in W-25%Re samples, producing a more recrystallized microstructure geometry and increasing the density to 98.8% of theoretical and the tensile strength to 659.8 MPa.