Progress in SiAlON ceramics

In view of the considerable progress that has been made over the last sever al years on the fundamental understanding of phase relationships, microstru ctural design, and tailoring of properties for specific applications of rar e-earth doped SiAlONs, a clear review of current understanding of the basic regularities lying behind the processes that take place during sintering o f SiAlONs is timely. Alternative secondary phase development, mechanism and full reversibility of the alpha to beta' transformation in relation with t he phase assemblage evolution are elucidated. Reaction sintering of multico mponent SiAlONs is considered with regard of wetting behavior of silicate l iquid phases formed on heating. Regularities of SiAlON's behavior and stabi lity are tentatively explained in terms of RE element ionic radii and acid/ base reaction principle. (C) 2000 Elsevier Science Ltd. All rights reserved .