Extensive research efforts are underway to generate composite coatings including carbon nanotubes (CNT) in order to improve the properties of the bulk coat. The present project concentrates on possible methods that would allow the plasma spraying of CNT-based nano-composite coatings. Various methods for producing metal-CNT composite powders for thermal plasma spraying are studied in this project. The first method discussed is based on CNT dispersion followed by an agglomeration procedure using a polymer binder. The second and more promising technique gets around the problems associated with handling, separating, and transporting the nanotubes to the substrate through a direct synthesis of the CNT on the particles to be sprayed. In the present context, this synthesis is made on pretreated stainless steel SS304 powders by chemical vapor deposition (CVD). A parametric study is made for the various steps of the thermal CVD process by varying parameters such as the etching time in the pre-treatment sequence, while the reaction temperature, the annealing temperature, the growth phase duration and the acetylene injection time are varied for the CVD sequence. The composite powders are analyzed using high resolution electron microscopy images (FEGSEM), thermogravimetric analyses (TGA), Raman spectroscopy, and BET surface area analyses. This study provided the parametric optimization of the thermal CVD procedure with respect to CNT production. The composite powders generated show a dense, fully covered, and uniform CNT forest with a purity of CNT to amorphous carbon of 86% based on the micro-Raman spectra obtained.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.112569 |
| Date | January 2008 |
| Creators | Fadlallah, Faysal Ghazi. |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Engineering (Department of Chemical Engineering.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 002711465, proquestno: AAIMR51459, Theses scanned by UMI/ProQuest. |
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