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2617 |
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Thursday, September 29, 2011, Saal C2.2 4:50 PM Corrosion Protection 3 |
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Silicon carbide based plasma sprayed coatings |
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Mario Tului / Centro Sviluppo Materiali S.p.A., Italy Barbara Giambi* / Centro Sviluppo Materiali, Italy Giovanni Pulci/ Sapienza University of Rome, Italy Teodoro Valente/ Sapienza University of Rome, Italy |
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Coatings containing up to 65 volume % of silicon carbide were deposited by plasma spray. Potential applications can be found in the protection of CMC (Ceramic Matrix Composite) against wear and high temperature oxidation. It is well known that SiC can not be deposited by thermal spray because it decomposes before melting. To face this problem, a mixture of SiC and ZrB2 was deposited, since those two compounds form an eutectic phase, at a temperature lower to the one of SiC decomposition. Coatings microstructure was characterised by XRD, SEM, and EDS, confirming the presence of SiC in the deposited layer and the formation of the eutectic phase during spraying. Samples of the coatings were exposed in air at high temperature, in the range between 1373 and 1773 K. The oxide scale was investigated by means of SEM and EDS. It was constituted by a SiO2 layer, which includes islands of ZrO2. Test results showed the good potentiality of the material investigated to be used as a protection against the high temperature oxidation. |