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An investigation of phase transformations in Pt-V coating systems
Includes bibliographical references.
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| Main Author: | |
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| Other Authors: | |
| Format: | Thesis |
| Language: | English |
| Published: |
Centre for Materials Engineering
2016
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| _version_ | 1867613187905421312 |
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| access_status_str | Open Access |
| author | Makhetha, William Motsoko |
| author2 | Lang, Candy |
| author_browse | Lang, Candy Makhetha, William Motsoko |
| author_facet | Lang, Candy Makhetha, William Motsoko |
| author_sort | Makhetha, William Motsoko |
| collection | Thesis |
| description | Includes bibliographical references. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/17104 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:32:09.918Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2016 |
| publishDateRange | 2016 |
| publishDateSort | 2016 |
| publisher | Centre for Materials Engineering |
| publisherStr | Centre for Materials Engineering |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/17104 An investigation of phase transformations in Pt-V coating systems Makhetha, William Motsoko Lang, Candy Topic, Mira Materials Engineering Includes bibliographical references. Phase transformations in Pt-V coatings after heat treatment have been investigated. Five Pt- V ordered phases (PtV, PtV 3 , Pt 2 V, Pt 3 V and Pt 8 V) have been previously observed in bulk platinum-vanadium alloys. Phase formation in coatings is expected to be sequential and controlled by the lowest temperature eutectic (liquidus) composition; this allows control of experimental parameters for formation of desired ordered phases. This investigation included fabrication of coatings, heat treatments, morphology characterization and phase analysis. Single and multilayer coatings ranging between 0.07 μm and 0.5 μm were deposited on vanadium and platinum substrates using E-beam deposition. The kinetics of phase transformation were studied by subjecting the coated layers to a variety of heat treatments in the temperature range 600°C to 900°C for 4 and 8 hours. Composition and morphology characterization was carried out using EDS and SEM respectively. XRD was used for phase analysis. Four (PtV, PtV 3 , Pt 2 V, Pt 3 V) out of the five Pt-V ordered phases exhibited in bulk alloys, were successfully formed from the coating system investigated in this project. The first phase formed, and the sequence of phase formation, was found to be different depending on which metal formed the substrate. The vanadium-rich ordered phase (PtV 3 ) was preferentially formed first on vanadium substrates and the sequence of phase formation progressed through ordered phases richer in platinum. The platinum-rich ordered phase (Pt 3 V) was preferentially formed first on platinum substrates and the sequence continued towards formation of ordered phases richer in vanadium. An increase in heat treatment temperature from 600°C to 900°C resulted in rapid kinetics of phase transformation but affected the morphology of the coatings. An increase in coating thickness, number of coating layers, heat treatment time, and temperature resulted in an increase in overall total number of ordered phases and volume of ordered phases. 2016-02-18T12:11:37Z 2016-02-18T12:11:37Z 2012 Master Thesis Masters MSc http://hdl.handle.net/11427/17104 eng application/pdf Centre for Materials Engineering Faculty of Engineering and the Built Environment University of Cape Town |
| spellingShingle | Materials Engineering Makhetha, William Motsoko An investigation of phase transformations in Pt-V coating systems |
| thesis_degree_str | Master's |
| title | An investigation of phase transformations in Pt-V coating systems |
| title_full | An investigation of phase transformations in Pt-V coating systems |
| title_fullStr | An investigation of phase transformations in Pt-V coating systems |
| title_full_unstemmed | An investigation of phase transformations in Pt-V coating systems |
| title_short | An investigation of phase transformations in Pt-V coating systems |
| title_sort | investigation of phase transformations in pt v coating systems |
| topic | Materials Engineering |
| url | http://hdl.handle.net/11427/17104 |
| work_keys_str_mv | AT makhethawilliammotsoko aninvestigationofphasetransformationsinptvcoatingsystems AT makhethawilliammotsoko investigationofphasetransformationsinptvcoatingsystems |