Nitrogen pressure effects on non-isothermal alumina sintering

The densification of a fine grained pure alumina powder was studied during gas pressure sintering. Different nitrogen pressures were applied during non-isothermal sintering runs up to final temperatures between 1150 °C and 1650 °C. Densification, porosity and microstructures have been investigated. A fine alumina powder presents a densification delay during nitrogen pressure sintering mainly due to the gas pressure effect at the beginning of the sintering. The main results of this work concern the influence of nitrogen pressure on non-densifying mechanisms and microstructural evolution, which only depends on densification rate.