Ceramic metal composites, or cermets, currently have widespread applications in the chemical, automotive and oil and gas sectors, due to their combination of high wear resistance, and aqueous corrosion resistance. In the present study, a family of novel titanium carbide (TiC)-stainless steel cermets has been produced as potential materials for use as erosion and corrosion resistant materials. The development of the TiC-stainless steel cermets is based on a simple melt infiltration technique, with the stainless steel “binder” contents varied from 5 to 30 vol.%, using the austenitic grades 304L and 316L, and the martensitic grade 410L. These materials have subsequently been evaluated for their wear and corrosion response, as well as characterisation of their basic mechanical properties and microstructure.
Results from wear and corrosion studies show an improvement in wear and corrosion resistance of the cermets at lower steel binder content . / The original abstract from thesis is below. Ceramic metal composites, or cermets, currently have widespread applications in the chemical, automotive and oil and gas sectors, due to their combination of high wear resistance, and aqueous corrosion resistance. In the present study, a family of novel titanium carbide (TiC)-stainless steel cermets has been produced as potential materials for use as erosion and corrosion resistant materials. The development of the TiC-stainless steel cermets is based on a simple melt infiltration technique, with the stainless steel “binder” contents varied from 5 to 30 vol.%, using the austenitic grades 304L and 316L, and the martensitic grade 410L. These materials have subsequently been evaluated for their wear and corrosion response, as well as characterisation of their basic mechanical properties and microstructure.
Reciprocating wear tests involved a ball-on-flat geometry (using a WC-Co counter face sphere), with loads varied from 20 to 80 N, for up to 120 minutes. The wear tracks were assessed using a high-resolution optical profilometer, in order to determine the wear volume. The specific wear rate of the cermets was found to increase with both the applied load and the steel binder content. To investigate the morphology of worn surfaces, scanning electron microscopy (SEM), and associated energy dispersive x-ray spectroscopy (EDS) were used, in order to fully understand the operative wear mechanisms. A transition from two- to three-body abrasive wear was observed, together with the formation of a oxygen-rich tribolayer, indicating that adhesive wear was also occurring on the cermets.
In order to assess the electrochemical behaviour of the cermets in a simulated seawater environment, the samples were evaluated using potentiodynamic, cyclic and potentiostatic polarisation tests, with basic corrosion parameters and rates subsequently determined through Tafel extrapolation and weight loss measurement. Each stage of electrochemical assessment was then evaluated by characterising the corroded surfaces and solution using SEM, EDS and inductively coupled plasma optical emission spectrometry. Microstructural observations using SEM images revealed significant degradation of the samples, with steel binder preferentially dissolved while TiC remained relatively unaffected. The corrosion rate of the cermets increases with steel binder content, which is attributed to the preferential dissolution of the binder.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:NSHD.ca#10222/28003 |
| Date | 17 June 2013 |
| Creators | Chukwuma Candidus, Onuoha |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
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