Effects of Heating Rate on Alumina Grain Growth

摘要

A rapid-heating method in the absence of electric/magnetic field was achieved by introducing a self-propagating-combustion(SHS) as heating source. The effect of heating rate on the alumina grain growth was explored based on this rapid-heating method. Comparing with the alumina prepared by two different heating ratios(greater than 1 000 ℃/min in SHS and about 50 ℃/min in common pressureless sintering furnace), it was revealed that the rapid heating could promote the grain growth greatly without pressure during sintering. However, if a pressure was applied simultaneously, the grain growth would be almost completely restrained. Since these observations are quite different from the expectation, a new grain growth model was proposed.