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:
High strength particulate ceramic composites are in general reinforced by strongdispersoids, such as strong ceramic particles (SiC, TiB2, ZrO2, et al) and strong metallic particles (Mo,W, et al). In this work high strength ceramic composites with in-situ synthesized hexagonal boronnitride (h-BN) have been prepared and characterized. As an example, we manufactured mullite-BNcomposites by reactive hot pressing (RHP) using aluminum borates (9Al2O3·2B2O3 and 2Al2O3·B2O3)and silicon nitride as starting materials. The obtained material RHPed at 1800°C showed a strength of540 MPa, which was 1.64 times higher than that of the monolithic mullite ceramics. TEM observationrevealed that the composite had an isotropic microstructure with a fine mullite matrix grain size ofless than 1 μm and a nano-sized h-BN platelets of about 200 nm in length and 60∼80 nm in thickness.The high strength was suggested to be from the reduced matrix grain size and the small tougheningeffect by the h-BN platelets. In addition, this kind of ceramic composite demonstrates low Young’smodulus that is beneficial to the thermal/mechanical shock resistance, and excellent machinability
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/51/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.317-318.163.pdf
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