Dilatometer setup for low coefficient of thermal expansion materials measurements in the 140 K-250 K temperature range

Space applications demand light weightmaterials with excellent dimensional stability fortelescopes, optical benches, optical resonators, etc. Glass-ceramics andcomposite materials can be tuned to reach very low coefficient ofthermal expansion (CTE) at differenttemperatures. In order to determine such CTEs, very accurate setups are needed. Here we present a dilatometer that is able tomeasure the CTE of a large variety ofmaterials in thetemperature range of 140 K to 250 K. The dilatometer is based on aheterodyneinterferometer with nanometer noise levels tomeasure theexpansion of a sample when applying small amplitude controlledtemperature signals. In this article, the CTE of a carbon fiber reinforced polymer sample has been determined with an accuracy in the 10−8 K−1 range.

Source: Review of Scientific Instruments - October 26, 2016 Category: Physics Authors: Ruven Spannagel, Ines Hamann, Josep Sanjuan, Thilo Schuldt, Martin Gohlke, Ulrich Johann, Dennis Weise and Claus Braxmaier Source Type: research