Densification, mechanical and microstructure properties of β-spodumene—alumina composites

Abstract

New systems consisting of ceramic composites have been recently developed to replace conventional alumina as a substrate for high performance large scale integrated packaging. Few investigations on the β-spodumene—alumina composites have been performed. Accordingly, the effect of β-spodumene content on the sintering behaviour and mechanical properties of the β-spodumene—alumina composites is the aim of the present study. Microstructural characteristics, thermal expansion and phase relations were also discussed. Fine β-spodumene and alumina powders of high purity were synthesized by aqueous sol-gel processing. The gels were dried and calcined and the resulting materials characterized by XRD. Various compositions of β-spodumene—alumina were prepared and conventional sintering studies were conducted at temperatures of 1400°–1600 °C with soaking periods of 1–4 h. The obtained results showed that densification was reduced with the increase of β-spodumene content. Mullite was detected in bodies containing 5% β-spodumene. There was no evidence of mullite presence with higher contents of β-spodumene. Increasing β-spodumene from 5 mass% up to 15 mass% increased the bodies bending strength by ≈43%, while the thermal expansion coefficient was slightly changed from 1.05 to 2.67×10⁻⁶/°C in the range of 20° to 1000 °C.