Fabrication and Applications of Rhenium and Rhenium Alloys

    Arc melting of rhenium in an inert atmosphere or vacuum is possible but the metal produced tends to have coarse grain size and may have segregation of rhenium oxides at the grain boundaries. These issues are a problem for further fabrication and powder metallurgy is the preferred answer to the problem. Rhenium powder is consolidated at pressure to a density of approximately 60% of the theoretical density of solid rhenium.

  The pressed compacts are then presintered in a hydrogen atmosphere to facilitate handling before final sintering. Rhenium alloys are produced by the same production methods as used for rhenium. Proper choice of powder sizes, careful blending and adequate sintering times and temperatures produce bars of hi yield and small grain size with the same homogeneity attainable by electron beam or arc melting. Subsequent fabrication is performed by swaging, rolling, forging and drawing with intermediate annealing. Some of these operations may have to be conducted at elevated temperatures. The optimum sequence of these operations varies for rhenium ad it alloys and depends on the final end form.

Applications:

•   Additive to tungsten and molybdenum-based alloys to increase ductility at higher temperatures;

•   Filaments for mass spectrographs and ion gauges;

•   Rhenium-molybdenum alloys become super-conducting at 10K;

•   Electrical contact material, as it has good wear resistance and withstands arc corrosion;

•   Thermocouples made of Re-W are used for measuring temperatures up to 2200° C;

•   Rhenium wire is used in flash lamps for photography.

  Rhenium can also be used in medical applications. While it is non-radioactive by nature it can be made radioactive by neutron bombardment. Radioactive rhenium is used in prevention and treatment of restenosis, which develops following balloon angioplasty. Rhenium can also be highly effective in the treatment of liver tumors.