Creep behavior of electron-beam-melted rhenium

Creep deformation in electron-beam-melted polycrystalline rhenium sheet was evaluated at 2200° to 4200°F (1477° to 2588°K) and 4 to 40 ksi (28 to 276 MN per sq m). Comparisons were made with powder metallurgy rhenium under similar conditions. Changes in creep-rupture behavior resulting from electron beam melting of rhenium were greater ductility, higher primary creep rate, and longer rupture life, especially at lower temperatures. The activation energy for creep was 72 kcal per mole for electron-beam-melted rhenium and 64 kcal per mole for powder metallurgy rhenium.