Preparation of AlN micro-honeycombs with high permeability via freeze-casting. Issue 13 (October 2020)

• Record Type: Journal Article
• Authors: Wei, Zhilei; Xie, Wenqi; Zhang, Xiaoyu; Zhang, Zhejian; Li, Yanjun; Xia, Hongyan; Wang, Bo; Shi, Zhongqi
• Is Part Of: Journal of the European Ceramic Society. Volume 40:Issue 13(2020)
• Page Start: 4462
• Page End: 4468
• Publication Date: 2020-10
• Subjects: AlN -- Freeze-casting -- Porosity -- Permeability -- Compressive strength; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2020.05.010
• Languages: English
• ISSNs: 0955-2219

Abstract

Highlights: Highly permeable AlN micro-honeycombs (AlN-Hs) were successfully fabricated via freeze-casting. The microstructure, open porosity, and N2 gas permeability of the AlN-Hs can be controlled by adjusting the solid loadings. The as-fabricated AlN-H with an open porosity of 64.9% display high N2 gas permeability and essential compressive strength. The AlN-Hs have shown significant promise for application in catalyst supports or filters. Abstract: Highly permeable AlN micro-honeycomb (AlN-H) ceramics with unidirectional macropore channels and porous struts were fabricated via tertiary butyl alcohol (TBA)-based freeze-casting. The effect of the AlN solid loading of the freezing slurries on the microstructure, open porosity, N2 gas permeability, and compressive strength of the as-prepared AlN-Hs were systematically investigated. The results showed that the honeycomb structure and open porosity of the AlN-Hs can be adjusted by altering solid loading. With the increase in solid loading from 10 vol% to 30 vol%, the approximate pore channel size of the AlN-Hs decreased from 50.1 μm to 15.6 μm, strut thickness increased from 8.2 μm to 16.6 μm approximately, and the corresponding open porosity decreased from 87.6–56.6%. The as-fabricated AlN-H with an open porosity of 64.9% possessed high N2 gas permeability and essential compressive strength and can be used as a catalyst support or filter in industries.