Fabrication of Novel Composites. Part III. The Thermal Conductivity and Linear Expansion of Ba-Mica/Alumina Composite Materials.

摘要

The addition of synthetic Ba-mica to alumina provides considerable enhancement of the mechanical properties of the basic ceramic. In order to usefully characterize materials of the system, a series of seven compositions with mica contents of 5 to 50 per cent were chosen for thermal conductivity evaluation. Measurements were made using the flat disc comparative method up to approximately 1,300 K on four and up to 1,100 k on the other three. The results are compared to those for a pure alumina material. The Y indicate the existence of a simple relationship between the thermal conductivity at different temperatures and density of the materials except for the 85 per cent alumina material. No conclusive explanation of this anomaly is available. Thermal expansion measurements for three selected materials were made to 1,300 K and the results presented to illustrate the effects of the different mica additions. (Author)