Dielectric characterization of high-performance spaceflight materials

Thumbnail Image
Date
2014-01-01
Authors
Kleppe, Nathan
Major Professor
Advisor
Nicola Bowler
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Altmetrics
Authors
Research Projects
Organizational Units
Organizational Unit
Materials Science and Engineering

The Department of Materials Science and Engineering teaches the composition, microstructure, and processing of materials as well as their properties, uses, and performance. These fields of research utilize technologies in metals, ceramics, polymers, composites, and electronic materials.

History
The Department of Materials Science and Engineering was formed in 1975 from the merger of the Department of Ceramics Engineering and the Department of Metallurgical Engineering.

Dates of Existence
1975-present

Related Units

Journal Issue
Is Version Of
Versions
Series
Abstract

As commercial space travel increases, the need for reliable structural health monitoring to predict possible weaknesses or failures of structural materials also increases. Monitoring of polymer-based materials may be achieved through the use of dielectric spectroscopy by comparing permittivity or conductivity measurements performed on a sample in use to that of a pristine sample. Changes in these measured values or of the relaxation frequencies, if present, can indicate chemical or physical changes occurring within the material and the possible need for maintenance/replacement. In this work, we established indicative trends that occur in the dielectric spectra during accelerated aging of various high-performance polymeric materials (EVOH, PEEK, PPS, and UHMWPE). Uses for these materials range from electrical insulation and protective coatings to windows and air- or space-craft parts that may be subject to environmental damage over long-term operation. Accelerated thermal aging and ultraviolet/water-spray cyclic aging were performed in order to investigate the degradation of the aforementioned material. The Havriliak-Negami model was used in the analysis of the measured dielectric spectra in order to obtain the characteristic fit parameters from which aging-related trends were identified. With reference to the literature and from measured FTIR spectra, observations were connected to the underlying mechanisms causing the dielectric relaxations.

Comments
Description
Keywords
Citation
Source
Copyright
Wed Jan 01 00:00:00 UTC 2014