Processing Problems of High Alumina Body

Abstract

Excessive firing shrinkage and secondary re-crystallization cannot be controlled if alumina powder produced from Bayer's process is exclusively used to develop dense alumina body. High alumina bodies having low firing shrinkage and controlled microstructure can, however, be developed using alumina powder from Bayer's process and fused alumina grains with MgO in the form of magnesio-aluminate hydrate (MAH) as sintering aid. By introducing fine alumina powder pre-calcined at an optimum temperature, a part of fused alumina grains can be replaced. The possibility of formation of bodies involving the entire range of graded fused alumina and fine technical alumina powder has been explored.