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Mechanical properties of anodized coatings over molten aluminum alloy

Journal of Colloid and Interface Science

Grillet, Anne M.; Gorby, Allen D.; Trujillo, Steven M.; Grant, Richard P.; Hodges, Vernon C.; Parson, Ted B.; Grasser, Thomas W.

A method to measure interfacial mechanical properties at high temperatures and in a controlled atmosphere has been developed to study anodized aluminum surface coatings at temperatures where the interior aluminum alloy is molten. This is the first time that the coating strength has been studied under these conditions. We have investigated the effects of ambient atmosphere, temperature, and surface finish on coating strength for samples of aluminum alloy 7075. Surprisingly, the effective Young's modulus or strength of the coating when tested in air was twice as high as when samples were tested in an inert nitrogen or argon atmosphere. Additionally, the effective Young's modulus of the anodized coating increased with temperature in an air atmosphere but was independent of temperature in an inert atmosphere. The effect of surface finish was also examined. Sandblasting the surface prior to anodization was found to increase the strength of the anodized coating with the greatest enhancement noted for a nitrogen atmosphere. Machining marks were not found to significantly affect the strength.

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TYPE Journal Article YEAR 2008
ScopusOSTIDOI

Circulating fluidized bed hydrodynamics experiments for the multiphase fluid dynamics research consortium (MFDRC)

Trujillo, Steven M.; Torczynski, J.R.; Tortora, Paul R.; O'Hern, Timothy J.

An experimental program was conducted to study the multiphase gas-solid flow in a pilot-scale circulating fluidized bed (CFB). This report describes the CFB experimental facility assembled for this program, the diagnostics developed and/or applied to make measurements in the riser section of the CFB, and the data acquired for several different flow conditions. Primary data acquired included pressures around the flow loop and solids loadings at selected locations in the riser. Tomographic techniques using gamma radiation and electrical capacitance were used to determine radial profiles of solids volume fraction in the riser, and axial profiles of the integrated solids volume fraction were produced. Computer Aided Radioactive Particle Tracking was used to measure solids velocities, fluxes, and residence time distributions. In addition, a series of computational fluid dynamics simulations was performed using the commercial code Arenaflow{trademark}.

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TYPE SAND Report YEAR 2006
OSTIDOI

Liquefaction and flow behavior of a thermally decomposing removable epoxy foam

High Performance Structures and Materials

Erickson, Kenneth L.; Trujillo, Steven M.; Thompson, Kyle R.; Sun, Amy C.; Hobbs, Michael L.; Dowding, Kevin J.

The investigation of the liquefaction and flow behavior of a thermally decomposing removable epoxy foam (REF) was discussed. It was concluded that the behavior of REF, can vary greatly depending on both physical and thermal boundary conditions as well as on decomposition chemistry. It was shown that the foam regression away from a heated surface generally involves two moving boundaries, a fluid-solid interface and a fluid-vapor interface. During thermal decomposition, the physical and chemical behaviors of the foams were coupled and can significantly affect heat transfer rates to the encapsulated units.

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TYPE Conference YEAR 2004
ScopusOSTI
14 Results
14 Results