Sintering of porous alumina obtained by biotemplate fibers for low thermal conductivity applications

• Published in: Journal of the European Ceramic Society Vol. 33; no. 6; pp. 1087 - 1092
• Main Authors: Delbrücke, Tiago, Gouvêa, Rogério A., Moreira, Mário L., Raubach, Cristiane W., Varela, José A., Longo, Elson, Gonçalves, Margarete R.F., Cava, Sergio
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-06-2013
• Subjects: Al2O3; Aluminum oxide; Ceramics; Chemically synthesized; Fibers; Fibres; Nanostructure; Precursors; Replica method in organic matrix; Sintered porous body; Sintering; Thermal conductivity; Thermal properties; Thermal properties; Sintered porous body; Chemically synthesized; Al2O3; Replica method in organic matrix
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2012.11.009

In this research report, a sintering process of porous ceramic materials based on Al2O3 was employed using a method where a cation precursor solution is embedded in an organic fibrous cotton matrix. For porous green bodies, the precursor solution and cotton were annealed at temperatures in the range of 100–1600°C using scanning electron microscopy (SEM) and thermogravimetric (TG) analysis to obtain a porous body formation and disposal process containing organic fibers and precursor solution. In a structure consisting of open pores and interconnected nanometric grains, despite the low porosity of around 40% (calculated geometrically), nitrogen physisorption determined a specific surface area of 14m2/g, which shows much sintering of porous bodies. Energy dispersive X-ray (EDX) and X-ray diffraction (XRD) analytical methods revealed a predominant amount of α-Al2O3 in the sintered samples. Thermal properties of the sintered Al2O3 fibers were obtained by using the Laser Flash which resulted in the lower thermal conductivity obtained by α-Al2O3 and therefore improved its potential use as an insulating material.