Controlled firing of reaction-bonded aluminum oxide (RBAO) ceramics: Part II, experimental results

The reaction-bonded aluminum oxide (RBAO) process is an attractive alternat ive to conventional processing of ceramics, because of advantages such as l ower costs, enhanced green machinability, near-net-shape forming, and broad microstructural variability. However, various problems are still encounter ed in the production of RBAO ceramics. Part I of the paper presented model predictions that may allow for the controlled firing of RBAO ceramics. The current work investigates the reaction behavior of RBAO ceramics under the model-predicted conditions (i.e., for varying oxygen content, heat loss, he ating cycles, and scale) via thermogravimetry, differential thermal analysi s, and analysis of samples that have been fired in a box furnace. By contro lling the reaction, one can produce large, crack-free RBAO ceramics.