Hot Pressing of Aluminum Oxide

Abstract

The hot‐pressing characteristics of two aluminum oxides were studied in order to acquire a better understanding of the densification process and to develop a method of predicting the effects of experimental conditions other than those actually tested. A rapid hot‐pressing technique was developed which greatly reduced the time element. The rate equation proposed by Murray, Livey, and Williams for hot‐pressing ceramics was found to hold for the two aluminas, thus making it possible to predict the effects of changes in hotpressing conditions. The equation used was . Viscosity, η, was calculated as a function of temperature using this equation and the experimental hot‐pressing results. Values varied from 1.2 × 10 12 poises at 1300°C. to 4.6 × 10 10 at 1600°C.