29 Result(s)
within
B. Gleeson
Materials Science
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Article
Effect of Nb on the high-temperature sulfidation behavior of cobalt
The sulfidation behavior of Co-Nb alloys containing up to 30wt.% Nb was studied in sulfur vapor at a pressure of 0.01 atm in the temperature range of 600–700°C. Increasing niobium content decreased the sulfida...
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Article
Phenomenological treatment of multilayer growth
A phenomenological treatment of multilayer growth has been carried out with three basic assumptions: (1) steady-state conditions existing at the phase boundary between two phases within the multilayer, (2) a w...
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Article
Oxygen tracer study of the high-temperature oxidation of pure and impure cobalt
Oxygen tracer experiments were used to examine the role of oxygen movement in the development of CoO scales at 1273 K and 1373 K. Samples were oxidized in various sequences of16O2 and18O2, and the resulting isoto...
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Article
A comprehensive investigation of the sulfidation behavior of binary Co-Mo alloys
The sulfidation behavior of Co-Mo alloys containing up to 40 wt.% Mo was studied over the temperature range 600–900°C in both 10−2 and 10−4 atm. sulfur vapor. All of the alloys were two-phase, with the alloys con...
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Article
The sulfidation behavior of Co-Mo alloys containing various ternary additions
The sulfidation behavior of Co-Mo-X alloys, where X is Al, Cr, Mn, or Ti, has been studied over the temperature range 600 or 700°C to 900°C in 10−2 atm. sulfur vapor to determine the effectiveness of the various ...
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Article
An extension of Wagner's analysis of competing scale formation
Wagner's criterion to predict the minimum concentration of solute (N B(min) 0 )necessary for the exclusive formation of its scale has been modified to incorpor...
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Article
A diffusional analysis of the oxidation of binary multiphase alloys
A nonsteady-state diffusional analysis has been applied to the oxidation of binary multiphase alloys. In addition to the solubility of the solute element in the continuous solid-solution phase, the volume frac.....
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Article
The hot-corrosion behavior of novel CO-deposited chromium-modified aluminide coatings
This paper reports the successful co-deposition of inclusion-free chromiummodified aluminide coatings using a pack-cementation process. The substrate used was the nickel-base superalloy, René 80H. The coatings...
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Article
Oxidation of multicomponent two-phase alloys
The high-temperature corrosion behavior of two-phase alloys presents a number of differences compared to that of single-phase alloys. These differences are mainly a consequence of the limitations that the pres...
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Article
The deposition of aluminide and silicide coatings on γ-TiAl using the halide-activated pack cementation method
The halide-activated pack cementation method (HAPC) was utilized to deposit aluminide and silicide coatings on nominally stoichiometric γ-TiAl. The deposition temperature was 1000°C and deposition times ranged...
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Article
The Long-Term, Cyclic-Oxidation Behavior of Selected Chromia-Forming Alloys
Long-term, cyclic-oxidation testing in still airfor about 2 years (720 days) at 982°C and 1 year(360 days) at 1093, 1149, and 1204°C has beenconducted on the commercial, high-temperaturechromia-forming HR-120®...
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Article
Factors Affecting Chromium Carbide Precipitate Dissolution During Alloy Oxidation
Ferrous alloys containing significant volumefractions of chromium carbides were formulated so as tocontain an overall chromium level of 15% (by weight) buta nominal metal matrix chromium concentration of only ...
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Article
Beneficial Effects of Rhenium Additions on the Cyclic-Oxidation Resistance of β-NiAl + α-Cr Alloys
This study reports the effects of up to 4 at.%rhenium addition on the cyclicoxidation behavior ofβ-NiAl + α-Cr alloys having a basecomposition (in at.%) Ni-40Al-17Cr. Tests were conductedin still air at 1100°C...
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Article
Rapid Growth of SiO2 Nanofibers on Silicon-Bearing Alloys
Exposure of Ni–Si and Co–Si alloys to Ar–CO2 and Ar–CO–CO2 gases at 1130°C led to rapid growth of crystalline SiO2 nanofibers from the alloy surfaces. The fibers were circular in cross section, of diameter about ...
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Article
Effects of Minor Elements on the Cyclic-Oxidation Behavior of Commercial Fe-Base 800-Series Alloys
The cyclic-oxidation behavior of commercial iron-base 800-series chromia-scale-forming alloys was studied at 1000°C in still air. Each thermal cycle consisted of one day at temperature followed by air cooling ...
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Article
Scaling of Carbon Steel in Simulated Reheat Furnace Atmospheres
A low carbon steel was exposed to a series of laboratory-simulated combustion gases at temperatures of 700--1200°C. The gases corresponded to the products of burning natural gas with amounts of air varying fr...
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Article
Effects of Silicon on the Oxidation Behavior of Ni-Base Chromia-Forming Alloys
This paper compares and analyzes the oxidation behavior of Ni-base alloys with and without about 2.7 wt.% Si addition. The Ni-base alloys studied were of two types: cast model alloys or wrought commercial allo...
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Article
Correlation between the Microstructure, Growth Mechanism, and Growth Kinetics of Alumina Scales on a FeCrAlY Alloy
The microstructural development of an alumina scale formed on a model FeCrAlY alloy during oxidation at 1200 °C was characterized for up to 2000 hours of growth. Quantitative scanning electron microscopy (SEM)...
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Article
Compositional factors affecting the establishment and maintenance of Al2O3 scales on Ni–Al–Pt systems
The beneficial role played by platinum addition in promoting the formation of a protective Al2O3 scale on representative γ′-Ni3Al+γ-Ni coating compositions during high-temperature oxidation is discussed. This ben...
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Article
Structural Stability of Platinum-Group-Metal-Modified γ + γ′ Ni-Base Alloys
The structural and surface stabilities of two experimental γ-Ni+γ′-Ni3Al-base alloys containing Pt or Ir were investigated. These alloys are representative of alloys currently being developed to occupy a unique d...
