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Materials Science and Engineering

Missouri University of Science and Technology

Doctoral Dissertations

Theses/Dissertations

Cobalt

Publication Year

Articles 1 - 3 of 3

Full-Text Articles in Engineering

Corrosion Protection Mechanisms Of Trivalent Chromium Based Passivations On Γ-Znni Coated Al6061-T6 Alloy, Kevin Foster Jan 2022

Corrosion Protection Mechanisms Of Trivalent Chromium Based Passivations On Γ-Znni Coated Al6061-T6 Alloy, Kevin Foster

Doctoral Dissertations

“The role of cobalt in trivalent chromium passivations (TCPs) to improve corrosion resistance of γ-ZnNi coated steel and aluminum is based on its effect on hexavalent chromium content in the passive layer. Investigations of both a cobalt-containing and cobalt-free TCP on SAE 1008 steel indicated that both passivations protect well for up to 1000 hours in neutral salt spray exposure (SSE). A repetition on Al 6061-T6 alloy indicated that TCP performed much better than cobalt-free TCP implicating the underlying substrate. Optical and electron micrographs indicated physical changes such as crack thickness, crack density, passivation porosity, and passivation thickness existed between …


Synthesis And Applications Of Ceramic (Silicon Carbide And Silicon Nitride), Metallic (Cobalt(0)) And Polymeric (Polyurethane) Aerogels, Parwani M. Rewatkar Jan 2019

Synthesis And Applications Of Ceramic (Silicon Carbide And Silicon Nitride), Metallic (Cobalt(0)) And Polymeric (Polyurethane) Aerogels, Parwani M. Rewatkar

Doctoral Dissertations

"A new method has been demonstrated for the synthesis of monolithic ceramic and purely metallic aerogels from xerogel powder compacts, and the use of polyurethane aerogels based on cyclodextrins as efficient desiccants.

I. Highly porous ( > 80%) monolithic SiC and Si3N4, aerogels were prepared from compressed compacts of polyurea-crosslinked silica xerogel powders. The process is time efficient as solvent-exchange through powders is fast, and energy efficient as it bypasses drying with supercritical fluids. The final ceramic objects were chemically pure, sturdy, with compressive moduli at 37 ±7 MPa and 59 ± 7 MPa, and thermal conductivities …


Electrodeposited Epitaxial Cobalt Oxides And Copper Metal, Caleb M. Hull Jan 2018

Electrodeposited Epitaxial Cobalt Oxides And Copper Metal, Caleb M. Hull

Doctoral Dissertations

"Electrochemical deposition methods are presented for the deposition of Co(OH)2 and Cu metal. Paper I shows the deposition of β-Co(OH)2 on Ti through electrochemical reduction of [Co(en)3]3+ to [Co(en)3]2+ in 2M NaOH. The catalytic properties of the deposited Co(OH)2 towards water oxidation is found comparable to Co3O4, with the surface of the Co(OH)2 converting to CoOOH during the reaction. Paper II gives the conditions suitable for epitaxial growth of Co(OH)2 on Au(100), Au(110), and Au(111) following the same reduction mechanism as described in Paper I. …