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Estimation of Damage in Refractory Materials after Progressive Thermal Shocks with Resonant Frequency Damping Analysis
N. Traon, T. Tonnesen, R. Telle
GHI/RWTH-Aachen, Aachen, Germany, Institute of Mineral Engineering – Department of Ceramics and Refractory Materials, Aachen, Germany
received December 4, 2015, received in revised form February 1, 2016, accepted February 20, 2016
Vol. 7, No. 2, Pages 165-172 DOI: 10.4416/JCST2015-00080
Abstract
This work correlates damping measurements and the microstructural changes in refractory castables after these have been exposed to thermal shocks in air. In accordance with DIN EN 993 – 11, refractory samples based on tabular alumina with the addition of partially stabilized zirconia (PSZ) were progressively subjected to thermal shocks in air at different temperatures (750, 850, 950 and 1050 °C). White fused alumina samples were also exposed to the same thermal shocks at 950 °C. Evaluation of the thermal shock damage to the high-alumina refractory castables was based on the dynamic Young's modulus and damping characterization data obtained by means of the impulse excitation technique (IET), in accordance with ASTM E1876 – 07. Scanning electron microscopy (SEM) was also performed to enable understanding of the elastic changes in these refractory formulations. The results show that the damping increase in PSZ castables may be explained by crack nucleation and propagation while such phenomena do not occur in WFA castable.
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Keywords
Thermal shock, impulse excitation technique, partially stabilized zirconia, Young's modulus, damping
References
1 Tonnesen, T., Telle, R.: Thermal shock damage in castables: Microstructural changes and evaluation by a damping method, cfi/Ber. DKG, 84, [9], E132 – 6, (2007).
2 Mielczarek, A., Fischer, H., Riehemann, W.: Amplitude-dependent damping of PSZ with sinter defects, Mat. Sci. Eng. A, 442, 488 – 491, (2006).
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 International Colloquium on Refractories (2010) Aachen, Germany, Proceedings, 90 – 93
4 Johnson, P.A., Zinszner, B., Rasolofosaon, N.J.: Resonance and elastic nonlinear phenomena in rock, J. Geophys. Res., 101, [B5], 11553 – 11564, (1996).
5 Abeele, K.V.D., Visscherb, J.: Damage assessment in reinforced concrete using spectral and temporal nonlinear vibration techniques, Cement Concrete Res., 301, 453 – 1464, (2000).
6 Liang, C., Liu, T., Xiao, J., Zou, D., Yang, Q.: The damping property of recycled aggregate concrete, Constr. Build. Mater., 102, 834 – 842, (2016)
7 Braulio, M.A.L., Cintra, G.B., Li, Y.W., Pandolfelli, V.C.: Aggregate effects on the thermal shock resistance of spinel-forming refractory castables, Refractories Worldforum, 2, 102 – 106, (2010).
8 Primachenko, V., Martynenko, V., Shulik, I., Kushchenko, P., Paschenko, N.: The influence of sintered or fused MgO-stabilized ZrO2 on properties of zirconia products, Proc. UNITECR 2007, 268 – 271, (2007)
9 Schnieder, J., Lynen, L., Traon, N., Tonnesen, Th., Telle, R.: Crack formation and shape of fracture surface in tabular-alumina-based castables with addition of specific aggregates, J. Ceram. Sci. Tech., 5, [2], 131 – 136, (2014).
10 Miyaji, D.Y., Tonnesen, T., Rodrigues, J. de A.: Fracture energy and thermal shock damage resistance of refractory castables containing eutectic aggregates, Ceram. Int., 40, [9], 15227 – 15239, (2014).
11 Schickle, B., Telle, R., Tonnesen, T., Changes of the mechanical and elastic properties of castables as a function of thermal shock cycles, 53rd International Colloquium on Refractories (2010) Aachen, Germany, Proceedings, 86 – 89, (2010).
12 Lee, W.E., Rainforth, M.: Ceramic microstructures: property control by processing, Mater. Corros., 47, [6], 346 – 347, (1996).
13 Hasselman, D.P.H.: Unified theory of thermal shock fracture initiation and crack propagation in brittle ceramics, J. Am. Ceram. Soc., 52, 600 – 604, (1969).
14 Hasselman, D.P.H., Thermal stress resistance parameters for brittle refractory ceramics: A compendium, Amer. Ceram. Soc. Bull., 49, 1033 – 1037, (1970).
15 Salvini, V.R., Pandolfelli, V.C., Bradt, R.C.: Extension of Hasselman's thermal shock theory for crack/microstructure interactions in refractories, Ceram. Int., 38, 5369 – 5375, (2012).
16 Miyaji, D.Y., Otofuji, C.Z., Rodrigues, J. de A.: The load-displacement curve of steady crack propagation: An interesting source of information for predicting the thermal shock damage of refractories, UNITECR 2013 Proceedings, 811 – 816
17 DIN EN 993 – 11: Determination of resistance to thermal shock, German version CEN/TS 993/11 (2003).
18 ASTM 1876 – 07: Standard Test Method for Dynamic Young's Modulus, Shear Modulus, and Poisson's Ratio by Impulse Excitation of Vibration. ASTM International, 15, (2007).
19 Pereira, H.A., Nascimento R.C., Exposito C.D., Martins T., Rodrigues J. de A., Johnson, P.A.: Elastic Moduli, damping and modulus of rupture changes in a refractory castable due to thermal shock damage, 52nd International Colloquium on Refractories, Aachen, Germany, Proceedings, 20 – 23 (2009).
20 Hasselman, D.P.H.: Role of fracture toughness in the thermal shock resistance of refractories (in German), Ber. Dtsch. Keram. Ges., 54, 195 – 201, (1954).
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