Partial Crystallization Behavior of Iron Based Glass-Coated Amorphous Metal

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dc.contributor.authorConklin, Morgan D.
dc.date.accessioned2011-10-21T19:45:12Z
dc.date.available2011-10-21T19:45:12Z
dc.date.issued2004
dc.description.abstractThermal and physical properties of glass-coated amorphous metal fibers have been investigated. It is demonstrated that an amorphous metal having a composition of Fe_{77.5}Si_{7.5}B_{15} undergoes a two-stage crystallization process when heated, and that the lower temperature crystallization can be completed without the higher temperature crystallization occurring. Scanning electron microscopy shows that such “Partial- Crystallization” creates a nanocrystalline, apparently interconnected structure within an amorphous matrix. The activation energy for the lower and upper temperature crystallizations have been calculated to be approximately 424 kJ/mol and 361 kJ/mol, respectively, using differential scanning calorimetry and Kissinger’s analysis. Crystallization temperature is heating rate dependant; at 10 ºC per minute, the two crystallizations occur at 540.5ºC and 550.5ºC respectively. Using a programmable dental furnace, a sample can be subjected to a heating curve and quenched in air, causing only the first crystallization to occur. The material so prepared is shown to have properties distinguished from the as-received material. The ultimate tensile strength of a partially crystallized fiber is measured to be 10-40% weaker than that of an as received sample. A core composition of Co_{68.15}Fe_{4.35}Si_{12.5}B_{16} has also been tested and has a single crystallization temperature (at 10ºC/min) of 552ºC with an activation energy of 503 kJ/mol. Using thermo-magneto-gravimetric analysis, Curie temperatures have been measured for the amorphous metal compositions; 426ºC for Fe_{77.5}Si_{7.5}B_{15}, and 319ºC for Co_{68.15}Fe_{4.35}Si_{12.5}B_{16}.en_US
dc.identifier.urihttp://hdl.handle.net/10829/304
dc.language.isoen-USen_US
dc.publisherAlfred University. Faculty of Ceramic Engineering. Kazuo Inamori School of Engineeringen_US
dc.subjectCoatingsen_US
dc.subjectCrystallizationen_US
dc.subjectDifferential scanningen_US
dc.subjectSEM analysisen_US
dc.subjectPorous glassesen_US
dc.subjectIronen_US
dc.subjectAmorphous metalsen_US
dc.titlePartial Crystallization Behavior of Iron Based Glass-Coated Amorphous Metalen_US
dc.typeThesisen_US

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