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Coated Columbium for Gas Turbine Engine Application
ISSN: 0148-7191, e-ISSN: 2688-3627
Published February 01, 1971 by SAE International in United States
Annotation ability available
High temperature strength and high thermal conductivity make columbium an attractive candidate for gas turbine engine components despite poor oxidation resistance relative to superalloys. The creep strengths of existing columbium alloys are adequate for burner and turbine vane applications up to metal temperatures of 2200-2400 F with considerably reduced cooling. The high conductivity and ductility of columbium along with low modulus and low thermal expansion coefficient produce very high resistance to thermal fatigue. In addition, the silicide coating technology has advanced to the point that multi-hundred hour lives at 2200-2400 F for coated columbium components are now attainable. The fabricability of air cooled turbine vanes from welded B-66 columbium alloy sheet has been demonstrated, including the coatability of air cooling passages with a slurry silicide. These vanes have run in a turbine development engine for 100 hr of steady state and cyclic operation at metal temperatures in excess of 2000 F. Coated columbium sheet alloys are also being evaluated for burner application with encouraging results. For example, thermal fatigue lives beyond 14,000 cycles to 2400 F have been measured, compared to less than 3000 cycles to 1800 F for nickel-base alloys including TD nickel. A film-cooled burner liner of FS-85 columbium alloy sheet material coated with the Sylvania SiCrFe slurry coating has been fabricated and will be rig- and engine-tested. The applicability of columbium to turbine vanes has recently been enhanced by the demonstration of an investment cast columbium vane shape.
CitationHolloway, J., Hauser, H., and Bradley, E., "Coated Columbium for Gas Turbine Engine Application," SAE Technical Paper 710460, 1971, https://doi.org/10.4271/710460.
- Sawyer J. C. Steigerwald E. A. “Creep Properties of Refractory Metal Alloys in Ultrahigh Vacuum,” Jrl. of Metals 2 2 June 1967 341
- Begley R. T. Cornie J. A. “Investigation of the Effects of Thermal Mechanical Variables on the Creep Properties of High Strength Columbium Alloy.” Westinghouse Astronuclear Laboratory Technical Report AFML-TR-69-224 1969
- Wurst J. C. Cherry J. A. “The Evaluation of High Temperature Materials,” Technical Report ML-TDR-64-62 II 1964
- Allen B. C. Bartlett E. S. “Elevated-Temperature Tensile Ductility Minimum in Silicide Coated Cb-10W and Cb-10W-2,5 Zr,” ASM Transactions Quarterly 60 3 September 1967 395 404
- Priceman S. Kubick R. “Development of Protective Coatings for Columbium Alloy Gas Turbine Blades.” Sylvania Electric Products, Inc. Interim Technical Progress Report STR 70-0194.8 1970
- Shierer S. T. “Devleopment of Columbium Alloy Combinations for Gas Turbine Blade Applications,” TRW, Inc. Technical Report AFML-TR-70-187 1970
- Cornie J. A. Goodspeed R. C. “Development of Ductile Oxidation Resistant Columbium Alloy.” Westinghouse Astronuclear Laboratory Technical Report AFML-TR-69-64 1969
- Hauser H. A. Holloway, J. F. Jr. “Evaluation and Improvement of Coatings for Columbium Alloy Gas Turbine Engine Components.” Pratt & Whitney Aircraft, Technical Report AFML-TR-66-186 1966
- Hauser H. A. Holloway, J. F. Jr. “Evaluation and Improvement of Coatings for Columbium Alloy Gas Turbine Engine Components.” Pratt & Whitney Aircraft, Technical Report AFML-TR-66-186 1968