ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
In this work, silicon carbide ceramics were developed by liquid phase sintering usingAlN-Y2O3 as additive. Two compositions were obtained using SiC powders and different contentsof AlN-Y2O3. The powders were mixed/homogeneizated and subsequently dried anddeagglomerated. Powder mixtures were compacted by cold isostatic pressing. Samples weresintered at 2080oC, for 1h, under 0.2 MPa-N2 atmosphere. Sintered samples were characterized byX-Ray diffraction and density. The oxidation behavior was investigated and related to thedensification and additive-content. Samples were submitted to the tests at 1200, 1300 or 1400oC, inair for 120 hours. Weight gain of the samples is plotted as function of the exposure time, obtainingthe evolution of the oxidation on the surface of the samples. Based on the results, the parabolicoxidation content (kp) and activation energy were determined. The results indicate that the samplespresent parabolic behavior in all conditions. The activation energy results indicate that thephenomena of diffusion of oxygen ions into the oxide layer and interfacial reactions between oxidelayer and intergranular phase are the responsible for oxidation mechanism
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/19/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.591-593.616.pdf
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