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.

Automated summary

Additively manufactured tungsten-rhenium alloys were compared with pure tungsten in terms of density, cracking behavior, microstructure, and hardness. Increasing rhenium content led to higher theoretical density and reduced cracking, especially evident in the W-25%Re composition. Postprocessing heat treatments improved microstructure and density of W-25%Re samples, increasing tensile strength to 659.8 MPa.