Published: 1962
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In work to develop materials for elevated temperature applications, binary niobium alloys containing either 2.37 wt% chromium, 3.34 wt% zirconium, or 5.21 wt% vanadium were fabricated to sheet by forging at 550 deg C and rolling at room temperature. All three alloys were completely recrystallized after 90% cold work (reduction in thickness) and a one hour anneal at 1150 deg C. Tensile tests on the annealed materials at 650, 800, 1000, 1150, and 1315 deg C indicated that chromium, zirconium, and vanadium are potent strengtheners of niobium. At 1000 deg C the 2.37 wt% chromium and the 5.21 wt% vanadium alloys had 0.2% offset yield strengths of 38,000 and 38,300 psi respectively. At 1315 deg C, the 3.34 wt% zirconium alloy had a 0.2% offset yield strength of 14,700 psi. Stresses to produce creep rates of 0.0001, 0.01, and 0.1% per hour were determined for all three alloys at 650, 800, and 1000 deg C. The vanadium alloy exhibited the greatest creep resistance, requiring stresses of 52,700, 40,000, and 15,500 psi to produce a creep rate of 0.001% per hour at 650, 800, and 1000 deg C respectively. This research indicated that significant improvement in the mechanical properties of niobium can be achieved by alloying without undue sacrifice of fabricability. (auth).