Tailored thermal expansivity in particulate composites for thermal stress management

Abstract

Only few composites with tailored thermal expansivity exist, even fewer with negative thermal expansivity fillers, and none are well characterised. Zirconium tungstate has an isotropic negative coefficient of thermal expansivity, and the overall coefficient of thermal expansivity (CTE) of a range of zirconium tungstate/epoxy composites was measured in order to examine the effects of volume fraction and particle surface treatment on the overall expansivity of the composite. This provides an improved understanding of how particulate composites, with negative CTE fillers behave on heating. The thermal expansivity of the composites containing negative thermal expansivity (NTE) fillers is shown to agree with a simple volume fraction model. © 2008 Wiley-VCH Verlag GmbH & Co. KGaA.