Construction of the master sintering curve for submicron size α-Al2O3 based on non-isothermal sintering containing lower heating rates only

The master sintering curve (MSC) is quite useful for analyzing the shrinkage behaviour of ceramics. In this study, the shrinkage behaviour for alpha-Al2O3 with a mean particle size of 350 nm during constant-heating-rate sintering were evaluated based on the MSC theory. An MSC for the above powder has been constructed using dilatometry data containing heating rates lower than 5 degrees C/min only with the help of combined-stage sintering model. The validity of the MSC has been verified by a few experimental runs. A comparison between predicted and experimental shrinkage curves showed good consistency, thus confirming that it is possible to control shrinkage behaviour using the MSC. The concept of the MSC has been used to evaluate the apparent activation energy for the above powder, and a high value of 1035 kJ/mol was obtained.