The Correction Method of Differential Dilatometer Data and Thermal Expansion Measurement of Carbon Materials

Abstract

The thermal expansion coefficient (α_t) of graphite has been measured as a function of temperature between room temperature and1000°C by using a differential dilatometer for the four grades of specimens;AXF-5Q1 (Poco Graphite Co.), 7477PT (Le Carbone Lorraine Co.), SM1-24 (Anglo Great Lakes Co.) and IG-11 (Toyo Carbon Co.).
The measurements have been carried out within an accuracy of1.1×10^-5 (ΔL/L₀) by taking into account the variation of environmental temperature and the temperature distribution in specimens, revealing that the thermal expansion is isotropic in AXF-5Q1, 7477PT and IG-11, and α_t of IG-11 is the lowest among them.