A three-dimensional mullite-whisker network ceramic with ultra-light weight and high-strength prepared by the foam-gelcasting method

Autor: Mengmeng Yang, Jijia Li, Yiran Man, Zijun Peng, Xiaofang Zhang, Xudong Luo
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Journal of Asian Ceramic Societies, Vol 8, Iss 2, Pp 387-395 (2020)
Druh dokumentu: article
ISSN: 2187-0764
21870764
DOI: 10.1080/21870764.2020.1747690
Popis: A three-dimensional mullite-whiskers network ceramic with ultra-light weight and high-strength was obtained by the foaming gel-casting method with active mulllite powders and NH4F. Ultrafine active mullite powder was used as the raw material and SDS (sodium dodecyl sulfate) as a pore-forming agent. The effects of sintering temperature on the microstructure, flexural strength and thermal conductivity of the porous ceramics were systematically investigated. The mullite-whisker network porous ceramic has a fibrous-framework structure composed of interweaving mullite-whiskers. Because the pore-walls are composed of interlacing whiskers and the pores are filled with whiskers, the porous ceramics exhibited good mechanical properties and low thermal conductivity. The flexural strength of the obtained mullite-whisker porous ceramic sintered at 1500°C was up to 1.45 Mpa, while the porosity was as high as 89%. In addition, the thermal conductivity of the porous ceramic at room temperature was as low as 0.045 W/m⋅K.
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