Dissertation/Thesis Abstract

Combinatorial assessment of the influence of composition and exposure time on the oxidation behavior and concurrent oxygeninduced phase transformations of binary Ti-x systems
by Samimi, Peyman, Ph.D., University of North Texas, 2015, 259; 10034391
Abstract (Summary)

The relatively low oxidation resistance and subsequent surface embrittlement have often limited the use of titanium alloys in elevated temperature structural applications. Although extensive effort is spent to investigate the high temperature oxidation performance of titanium alloys, the studies are often constrained to complex technical titanium alloys and neither the mechanisms associated with evolution of the oxide scale nor the effect of oxygen ingress on the microstructure of the base metal are well-understood. In addition lack of systematic oxidation studies across a wider domain of the alloy composition has complicated the determination of composition-mechanism-property relationships. Clearly, it would be ideal to assess the influence of composition and exposure time on the oxidation resistance, independent of experimental variabilities regarding time, temperature and atmosphere as the potential source of error. Such studies might also provide a series of metrics (e.g., hardness, scale, etc) that could be interpreted together and related to the alloy composition.

In this thesis a novel combinatorial approach was adopted whereby a series of compositionally graded specimens, (Ti-xMo, Ti-xCr, Ti-xAl and Ti-xW) were prepared using Laser Engineered Net Shaping (LENS™) technology and exposed to still-air at 650 °C. (Abstract shortened by ProQuest.)

Indexing (document details)
Advisor: Collins, Peter C.
Commitee:
School: University of North Texas
Department: Materials Science and Engineering
School Location: United States -- Texas
Source: DAI-B 77/08(E), Dissertation Abstracts International
Source Type: DISSERTATION
Subjects: Materials science
Keywords: Additive manufacturing, Atom probes, Oxidation, Phase transformation, TEM, Titanium alloys
Publication Number: 10034391
ISBN: 9781339536873
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