A novel hollow alumina sphere-based ceramic bonded by in situ mullite whisker framework. (15th January 2020)

• Record Type: Journal Article
• Authors: Yang, Mengmeng; Li, Jijia; Man, Yiran; Peng, Zijun; Zhang, Xiaofang; Luo, Xudong
• Is Part Of: Materials & design. Volume 186(2020)
• Publication Date: 2020-01-15
• Subjects: Hollow alumina sphere -- Mullite whisker -- Interlocked framework -- Porous ceramic -- Binding agent; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2019.108334
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: In this study, a novel hollow alumina sphere-based ceramic enhanced by in situ mullite whisker framework was recommended. Hollow alumina spheres selected as the main pore-forming agent were bonded together by an active mullite powder at high temperature. To improve the mechanical properties of the hollow alumina sphere-based ceramic, AlF3 powder was added into the active mullite powder to fabricate the mullite whisker framework during the sintering process. The mechanical properties of as-received hollow alumina spheres ceramic can be tailored by the sintering procedure. The results indicated that the sample sintered at 1400 °C exhibited a low bulk density of 1.005 g/cm 3 and a low thermal conductivity of 0.656 W/mK. The high aspect ratio of mullite whisker interacting with each other formed a unique framework structure, which enhanced the flexure strength (reaching 5.05 MPa) of the sample. Graphical abstract: Unlabelled Image Highlights: Novel hollow alumina sphere-based porous ceramic were prepared. Hollow alumina spheres were bonded by the in-situ mullite whisker framework structure. The hollow alumina sphere-based porous ceramic possess excellent mechanical properties. The composites have excellent thermal insulation performance at high temperature.