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:
The overall mechanical characterization of hot-pressed hexagonal boron nitride (h-BN)based ceramics was performed. Hardness, flexure strength and fracture toughness (KIC)measurements were carried out using Vickers indentations, 3-point bending tests and SEVNBmethod, respectively. The fracture characteristics of hot-pressed h-BN ceramics were investigatedby analyzing fracture surfaces using scanning electron microscope (SEM). The hardness, rangedfrom HV = 0.20GPa to HV = 0.25GPa, which was higher in the surfaces parallel to the hot-pressdirection due to the perpendicular alignment of the basal planes of the h-BN platelets to the hotpressdirection. The fracture toughness and flexure strength values were determined to be 2.6MPa.m1/2 and 0.14 GPa, respectively. A single KIC value was obtained since a slight variation of thefracture toughness was observed with the orientation of h-BN. The microstructural observations ofh-BN grains indicated completely brittle fracture with intergranular voids and microcracks revealinga mixed mode of fracture
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/16/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.554.201.pdf
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