Effect of Sintering Pressure and Rising Speed on Densification, Bending Strength and Microstructure of Alumina Ceramics Prepared by Spark-Plasm-Sintering

Abstract

An effect of sintering pressure and rising speed of temperature on the densification, bending strengths and microstructure of alumina ceramics prepared by spark-plasma-sintering was investigated at 1350°C or 1400°C for 0.3ks. No effect of spark-plasma-sintering was observed at a sintering pressure of 10MPa. Above 10MPa, the spark-plasma-sintering brought higher densities in comparison with the hot-press. But the sintering pressure was too high to accelerate the grain growth and the strengths deteriorated. Slower the rising speed, higher the densities. However the rising speed was too slow to promote the grain growth and the strengths dropped. It is necessary to select the proper sintering pressure and rising speed in the case of firing the materials by the spark-plasma-sintering.