Petrasek, D. W.
Materials engineer, NASA Lewis Research Center, Cleveland, Ohio
Signorelli, R. A.
Head, NASA Lewis Research Center, Cleveland, Ohio
Pages: 12 Published: Jan 1969
The potential of tungsten-2 percent thoria, 218 tungsten, and tungsten-1 percent thoria wire reinforced nickel-base superalloy composites for turbine bucket applications was evaluated based on stress-rupture strength, oxidation, and impact resistance. The results indicate that refractory metal alloy fiber-superalloy composites have potential for turbine bucket use based on the properties measured. Composites were produced having stress-rupture properties superior to conventional cast superalloys at use temperatures of 2000 and 2200 F. The 100 and 1000-h stress-rupture strength of the composite at 2000 F was 49,000 and 37,000 psi, respectively. A few thousands of an inch of matrix or cladding material was found to be sufficient to protect the fibers from oxidation at 2000 F for times up to 300 h. At 300 F and above the impact resistance of the composite compares favorably with that of superalloys.
fiber reinforcement, fiber composites, superalloy, mechanical properties, turbojet engine, turbine bucket alloy, oxidation, high-temperature alloy, refractory fiber, tungsten wire, evaluation, tests
Paper ID: STP49831S