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7408 |
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Wednesday, May 04, 2022, Hall -2.32/33 2:20 PM Suspension Spraying I |
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Development of thermal sprayed carbide and boride coatings by an innovative suspension/solution precursors approach |
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Acacio Rincon Romero* / University of Nottingham, Great Britain Tanvir Hussain / Faculty of Engineering, University of Nottingham, UK Alex Lynam/ Faculty of Engineering, University of Nottingham, UK Federico Venturi/ Faculty of Engineering, University of Nottingham, UK |
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Carbide and borides are interesting materials for many wears resistant and high temperature applications, however, the production of coatings with these materials represents a significant challenge as they tend to oxidise or decompose into gaseous phases when they are exposed to the extreme thermal spray conditions. An innovative method merging suspension and solution precursors was developed to allow the production of carbide composite coatings. Suspensions of carbides and borides were modified with the addition of oxide precursors to obtain composite coatings by high-velocity oxy-fuel (HVOF) thermal spray. The transformation of these oxides precursors and its subsequent melting during spraying contributes to protect the carbides and borides from the oxidising conditions, avoids their degradation during the spray process and supports the development of dense coatings as it was demonstrated by dispersive X-ray spectroscopy and X-ray diffraction analysis. The relationships between processing and microstructure were studied in terms of porosity phase distribution and mechanical properties proving that this novel approach could be applied to obtain coatings of materials that are prone to decompose during thermal spraying. |