The Understanding of the Microstructural Changes of Refractory Castables after Thermal Shocks through Damping Measurements

Nicolas Traon1, Thorsten Tonnesen2, Rainer Telle2

1 GHI/RWTH-Aachen, Institute of Mineral Engineering – Department of Ceramics and Refractory Materials, 52062 Aachen/Germany
2 RWTH-Aachen, Institute of Mineral Engineering – Department of Ceramics and Refractory Materials, 52062 Aachen/Germany

Revision 06.10.2011, 24.10.2011

Volume 4, Issue 1, Pages 119-124


The work herein correlates the damping measurements and themicrostructural modifications of refractory castables after thermalshocks at air. According to DIN EN 993-11, thermal shock at air atdifferent temperatures (750, 850, 950 and 1050 °C) were progressivelyconducted on refractory samples based on tabular aluminawith addition of partially stabilized zirconia (PSZ). The same thermalshocks were carried out at 950 °C on white fused alumina samplesas well. The thermal shock damage evaluation of high-alumina refractorycastables was based on dynamic Young’s modulus anddamping characterization data obtained via the impulse excitationtechnique (IET), according to the ASTM E1876-07. Scanning ElectronMicroscopy (SEM) completes this survey so as to understand theelastic changes of these refractory formulations. The results showthat the damping increase in PSZ castables may be explained bycrack nucleation and propagation while such phenomena do notoccur in WFA castable.


thermal shock, impulse excitation technique, partially stabilized zirconia, Young’s modulus, damping


[1] Tonnesen, T.; Telle, R.: Thermal shock damage in castables: Microstructural changes and evaluation by a damping method. cfi/Ber. DKG 84 (2007) [9] E132–136.

[2] Mielczarek, A.; Fischer, H.; Riehemann, W.: Amplitudedependant damping of PSZ with sinterdefects. Mater. Sci. Engin. A 442 (2006) 488–491

[3] Pereira, H.A.; Nascimento, R.C.; Rodrigues, J. de A.: Effect of non linearity on Young’s modulus and damping characterisation of high alumina refractory castables through the impulse excitation technique. 53rd Int. Coll. on Refractories (2010) Aachen, Germany, Proc. 90–93 

[4] Johnson, P.A.; Zinszner, B.; Rasolofosaon, N.J.: Resonance and elastic nonlinear phenomena in rock. J. Geophys. Res. 101 (1996) [B5] 11553–11564

[5] Abeele, K.V.D.; Visscherb, J.: Damage assessment in reinforced concrete using spectral and temporal nonlinear vibration techniques. Cement and Concrete Res. 30 (2000) 1453–1464.

[6] Braulio, M.A.L.; et al.: Aggregate effects on the thermal shock resistance of spinel-forming refractory castables. Refractories Worldforum (2010) [2] 102–106

[7] Primachenko, V.; et al.: The influence of sintered or fused MgO-stabilized ZrOon properties of zirconia products. Proc. UNITECR 2007 (2007) 268–271

[8] Schickle, B.; Telle, R.; Tonnesen, T.: Changes of the mechanical and elastic properties of castables as a function of thermal shock cycles. 53rd Int. Coll. on Refractories (2010) Aachen, Germany, Proc. 86–89

[9] DIN EN 993-11: Determination of resistance to thermal shock, German version CEN/TS 993/11 (2003)

[10] ASTM 1876-07: Standard test method for dynamic Young’s modulus, shear modulus, and Poisson’s ratio by impulse excitation of vibration. ASTM International (2007) 15

[11] Pereira, H.A.; et al.: Elastic moduli, damping and modulus of rupture changes in a refractory castable due to thermal shock damage. 52nd Int. Coll. on Refractories (2009) Aachen, Germany, Proc. 20–23

[12] Hasselman, D.P.H: Rolle der Bruchzähigkeit bei der Temperaturwechselbeständigkeit feuerfester Erzeugnisse. Ber. DKG 54 (1954) 195–201


© Göller Verlag GmbH