Dissertation/Thesis Abstract

Oxidation of Niobium Silicides Obtained by Self-Propagating High-Temperature Synthesis
by Perez, Frank Anthony, M.S., The University of Texas at El Paso, 2020, 61; 28028868
Abstract (Summary)

Niobium silicide-based composites are promising materials for high-temperature structural applications, such as gas turbines. One attractive method for their fabrication is mechanically activated self-propagating high-temperature synthesis (MASHS). However, oxidation resistance of niobium silicides produced by MASHS has not been studied yet. In this present work, the oxidation of Nb/Nb5Si3 composites obtained by MASHS was investigated by using non-isothermal thermogravimetric analysis (TGA) and differential scanning analysis (DSC). Both techniques have shown that the oxidation starts at about 500 °C and the materials become fully oxidized at 750 – 800 °C. Model-based analysis of the TGA data has shown that the Avrami-Erofeev nucleation and three-dimensional diffusion models exhibit the best fit with the TG curves and predict similar values of the apparent activation energy, 193 and 212 kJ/mol, respectively.

Indexing (document details)
Advisor: Shafirovich, Evgeny
Commitee: Bronson, Arturo, Roberson, David
School: The University of Texas at El Paso
Department: Engineering
School Location: United States -- Texas
Source: MAI 82/3(E), Masters Abstracts International
Source Type: DISSERTATION
Subjects: Mechanical engineering, High Temperature Physics, Thermodynamics
Keywords: Oxidation, Niobium silicide, Self-propagating, High-temperature synthesis
Publication Number: 28028868
ISBN: 9798664777499
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