Fabrication of near net shape magnesium aluminate (MgAl2O4)spinel components via aqueous processing

Abstract

Net shape fabrication of magnesium aluminate (MgAl2O4)spinel (MAS) components like domes and radomes is of great importancebecause they are employed in certain important strategic applications. Environmentallyand economically benign net-shape forming techniques such as aqueous gelcasting (GC)and hydrolysis induced aqueous gelcasting (GCHAS) cannot be employedto MAS powder as it reacts with water during processing and makes the processcumbersome. The processes reported in the literature to overcome this problemand for successful fabrication of net shape MAS components like thin wallradomes/crucibles following aqueous colloidal processing routes such as GCand GCHAS are reviewed in this paper. This article also reviews the effectof surface treatment of MAS powder against hydrolysis and of consolidationroute on net shape forming capability and the sintering ability of MAS powder.Furthermore, various other net shaping techniques reported for MAS are alsoreviewed in this article.