[PDF] Cyclic Oxidation Of Cobalt Based Alloys eBook

Author : National Aeronautics and Space Administration (NASA)
Publisher : Createspace Independent Publishing Platform
Page : 196 pages
File Size : 21,92 MB
Release : 2018-07-18
Category :
ISBN : 9781723145506

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Specific-weight-change-versus-time data and x ray diffraction results are presented derived from high temperature cyclic tests on high temperature, high strength nickel-base gamma/gamma prime and cobalt-base turbine alloys. Each page of data summarizes a complete test on a given alloy sample. Barrett, Charles A. and Garlick, Ralph G. and Lowell, Carl E. Glenn Research Center COBALT ALLOYS; HEAT RESISTANT ALLOYS; HIGH STRENGTH ALLOYS; NICKEL ALLOYS; OXIDATION; TURBINES; DENSITY (MASS/VOLUME); HIGH TEMPERATURE TESTS; X RAY DIFFRACTION...

Author : National Aeronautics and Space Administration (NASA)
Publisher : Createspace Independent Publishing Platform
Page : 30 pages
File Size : 30,46 MB
Release : 2018-07-26
Category :
ISBN : 9781724273703

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The corrosion of sodium sulfate coated cobalt alloys was measured and the results compared to the cyclic oxidation of alloys with the same composition, and to the hot corrosion of compositionally equivalent nickel-base alloys. Cobalt alloys with sufficient aluminum content to form aluminum containing scales corrode less than their nickel-base counterparts. The cobalt alloys with lower aluminum levels form CoO scales and corrode more than their nickel-base counterparts which form NiO scales. Santoro, G. J. Glenn Research Center NASA-TM-79311, E-267

Author : Joseph R. Stephens
Publisher :
Page : 30 pages
File Size : 49,9 MB
Release : 1983
Category : Aircraft gas-turbines
ISBN :

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The United States imports over 90 percent of its cobalt, chromium, tantalum and columbium -- all key elements in high temperature nickel-base superalloys for aircraft gas turbine disks and airfoils. NASA, through joint government/industry/university teams, has undertaken a long-range research program (COSAM - Conservation of Strategic Aerospace Materials) aimed at reducing or eliminating these strategic elements by examining their basic roles in superalloys and identifying viable substitutes. This paper discusses research progress in understanding the effects of cobalt and some possible substitutes on microstructure, mechanical properties, and environmental resistance of turbine alloys. (Author).

Author : Vincent F Hock (Jr)
Publisher :
Page : 161 pages
File Size : 36,37 MB
Release : 1977
Category :
ISBN :

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The rates of oxidation and hot corrosion of pure cobalt, cobalt-chromium, cobalt-silicon and cobalt-chromium-silicon alloys were determined at 1000 C in oxygen at a pressure of 0.1 atmosphere. The hot corrosion studies were conducted under conditions of a continous supply of Na2S04 to the sample surface. In addition, the effect of thermal cycling on the hot corrosion resistance of the Co-15 Cr-Si alloy group was also investigated. For the cobalt-chromium alloys, it was found that a considerable decrease in the oxidation and hot corrosion rates occurred at chromium concentrations about 15 wt. %. The cobalt-silicon binary alloys showed a dramatic increase in the rate of oxidation up to 0.05 wt. % silicon according to normal doping theory. At silicon concentrations greater than 5 wt. %, a marked decrease in oxidation and hot corrosion was observed. Generally, the series of cobalt-chromium-silicon alloys exhibited much better oxidation and hot corrosion resistance than the binary alloys. The lowest rates were obtained for alloys with high silicon contents. One alloy in particular, Co-10 Cr-10 Si, exhibited the lowest total weight gain per unit area for both oxidation and hot corrosion. The hot corrosion resistances of the Co-15 Cr-Si alloys were decreased by thermal cycling. (Author).

Author : National Aeronautics and Space Administration (NASA)
Publisher : Createspace Independent Publishing Platform
Page : 468 pages
File Size : 23,61 MB
Release : 2018-07-25
Category :
ISBN : 9781724237286

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Specific-weight-change-versus-time data and x ray diffraction results are presented derived from high temperature cyclic tests on high temperature, high strength nickel-base gamma/gamma prime and cobalt-base turbine alloys. Each page of data summarizes a complete test on a given alloy sample. Barrett, Charles A. and Garlick, Ralph G. Glenn Research Center NASA-TM-101468, E-4263-PT-2, NAS 1.15:101468 RTOP 505-63-01...