M. Ghassemi Kakroudi,
Volume 5, Issue 4 (12-2008)
Abstract
Abstract: Refractory materials containing cordierite (2MgO.2Al2O3.5SiO2) and mullite (3Al2O3.2SiO2) are used as
support in furnaces, because of their low thermal expansion properties which confer them a very good ability to
thermal shock resistance. Composed of two phases presenting very different CTE (1.5–3×10-6 for cordierite and
4–6×10-6 K-1 for mullite), these materials can develop damage during thermal cycling due to internal stresses.
The resulting network of microcracks is well known to improved thermal shock resistance of materials, since it usually
involves a significant decrease in their elastic properties. This paper is devoted to the characterisation of the damage
generated by this CTE mismatch, thanks to the application of a specific ultrasonic device at high temperature.
