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5228 |
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Wednesday, June 07, 2017, Hall 14 2:00 PM Medical Industry II |
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Sintering treatment after deposition of suspension plasma sprayed bioactive glass coatings |
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Eugeni Cañas* / Universitat Jaume I, Spain Mónica Vicent / Instituto de Tecnología Cerámica (ITC), Asociación de Investigación de las Industrias Cerámicas (AICE), Universitat Jaume I (UJI), Spain María José Orts/ Instituto de Tecnología Cerámica (ITC), Asociación de Investigación de las Industrias Cerámicas (AICE), Universitat Jaume I (UJI), Spain Enrique Sánchez/ Instituto de Tecnología Cerámica (ITC), Asociación de Investigación de las Industrias Cerámicas (AICE), Universitat Jaume I (UJI), Spain |
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Bioactive glasses (BGs) are emerging as substitutes of hydroxyapatite in the development of bioactive coatings since they show excellent bioactivity. Their deposition can be done by several methods, being the group of thermal spraying techniques one of the most versatile. In the last years suspension plasma spraying (SPS) is gaining interest among the rest of conventional techniques owing to the advantages of the use of a suspension feedstock. However, during deposition melted glass particles develop rapid sintering when impacting the substrate, making the release of gas bubbles difficult what results in an impaired coating microstructure and adherence. Therefore, the aim of the present work is to improve the microstructure of SPS bioactive coatings by using a post-spray heat treatment. For that purpose, a bioactive glass suspension was prepared from a BG powder, with particle size finer than 63 µm and a composition close to the 45S5 bioactive glass, using dipropylene glycol methyl ether as suspension liquid. In addition, the obtained suspension was stabilised through rheological and sedimentation tests. Then, the suspension feedstock was deposited by SPS onto two types of substrates: AISI type 304 stainless steel and grade 5 titanium alloy (Ti6Al4V). Finally, the obtained coatings were heated in air inside a furnace at different sintering temperatures and/or times, and the resulting coatings were microstructurally examined by scanning electron microscopy, image analysis and X-ray diffraction, Moreover, the adhesion strength of all coatings was assessed following the ASTM-C633 standard. Microstructure and adherence of the coatings were significantly enhanced after a specific sintering treatment without glass devitrification. This work has been supported by Research Promotion Plan of the Universitat Jaume I (ref. RECUBIO/P1-1B2013-69). |