Lime-alumina-silica processing incorporating minerals

The use of naturally occurring minerals to enhance the physical and mechani cal proper ties of industrial ceramics such as alumina is an attractive alt ernative to synthetic materials due to cost, chemical stability and availab ility. Two systems, have been chosen for investigation, alumina-kyanite to produce an alumina-mullite composite and alumina-wollastonite to produce a lime aluminosilicate. Wet processing conditions were optimised using pH/rhe ology and microelectrophoresis techniques followed by slip casting. The res ulting green compacts were subjected to a variety of sintering regimes to p roduce the desired composites. Sintered products were characterised by tech niques such as electron probe microanalysis, hardness tests and toughness d eterminations. Results are discussed both in terms of enhanced properties r ealised (toughness, wear resistance, dielectric), and with respect to the v iability of using natural minerals in this application. (C) 1999 Published by Elsevier Science Limited. All rights reserved.