Ceramics-Silikáty 53, (2) 98 - 101 (2009)

The purpose of this study is to determine the influence of nano-alumina particles on the self-flow characteristics of aluminaspinel self-flowing castables. For this reason, the self-flow characteristics such as; self-flow value and working time of the alumina-spinel castables with different amount of nano-alumina particles have been studied. Also, the mechanical properties and microstructure of these castables have been studied. For the study of nano-alumina (d₅₀ =4 3 nm) addition on selfflow characteristics and other properties of these castables, reactive alumina is substituted by nano-alumina powder in 0-4 wt.% range. The results show that the nano-alumina particles have great effect on the self-flow characteristics and mechanical strength. With increase of nano-alumina particles in castable composition, the self-flow value and working time tends to decrease and cold crushing strength is enhanced at all temperatures. By use of 1.5 wt.% nano-alumina contents in the castable composition, the alumina-spinel self-flowing castable with adequate working time and very high mechanical strength can be obtained.