Fabrication and compressive properties of closed-cell alumina ceramics by binding hollow alumina spheres with high-temperature binder

摘要

Here a facile method to fabricate closed-cell alumina ceramics by binding hollow alumina spheres with high-temperature binder was introduced. Hollow alumina spheres as the pore-forming agent were bonded together by silica and phosphate binder to form closed-cell structure at the high temperatures. The mechanical properties of as-received closed-cell alumina ceramic can be tailored by the volume fraction of hollow alumina spheres and sintering schedule. Besides, the effects of fusing agent B2O3 and chopped mullite fiber on bulk density and compressive strength of closed-cell alumina ceramics were investigated, respectively. The results indicated that the addition of chopped mullite fiber can effectively enhance the compressive strength of the closed-cell alumina ceramic without significant change in bulk density. The compressive strength of the closed-cell alumina ceramics with 62.5% total porosity was 11.97 MPa when 5 wt% B2O3 and 6 wt% chopped mullite fibers were added in the sample. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.