کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1474438 | 991089 | 2014 | 5 صفحه PDF | دانلود رایگان |
Boron nitride bonded porous silicon aluminum oxynitride composite was fabricated by gel-casting, precursor infiltration and pyrolysis process, and the composition, microstructure, mechanical and dialectical properties of the composite were characterized. The results show that the composite is comprised of β-SiAlON (z = 3) synthesized from mixed ceramic powders, and continuous h-BN pyrolyzed from borazine, with a relatively high porosity of 24.21%. The flexural strength, elastic modulus and fracture toughness of the composite are 178.58 MPa, 75.51 GPa and 4.54 MPa m1/2, respectively. The sintering shrinkage of SiAlON ceramics can be greatly decreased by the borazine infiltration and pyrolysis process. The existence of h-BN phase and the high porosity reduce the values of dielectric constant and loss tangent of the composite, which are 3.51–3.69 and 0.9–3.1 × 10−3 at the frequency from 7 to 18 GHz with the elevating temperature from 25 to 1200 °C.
Journal: Journal of the European Ceramic Society - Volume 34, Issue 15, December 2014, Pages 3591–3595