ISSN:
1013-9826
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:
Transparent Mg-Al spinel ceramics of four different nonstoichiometries were obtainedutilizing two-stage sintering technique of vacuum sintering and post hot isostatic pressing usingMgO·nAl2O3 powders with n of 1, 1.3, 1.5 and 1.8, respectively, as raw materials. The mechanicalproperties of the ceramics were measured and indentation shapes and radial crack propagations wereobserved. The results showed that change of molar ratio of Al2O3 to MgO leads to variation ofindentation shapes and crack propagations of the ceramics, resulting in the change of mechanicalproperties of the ceramics. The flexural strengths of the ceramics increase first then decrease withincreasing n. However, the hardness and fracture toughness of the ceramics increase with increasing n.As a result, an optimal n for high performance ceramic is suggested to be 1.5. In addition, mechanismsof toughening and strengthening of the transparent ceramics have also been discussed
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/53/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.336-338.1207.pdf
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