Thermal shock resistance of mullite/Sr-celsian/zirconia composites

Rodríguez-Salazar, P.; Almanza-Robles, J. M.; Cortés-Hernández, D. A.; Escobedo-Bocardo, J. C.; Rodríguez-Salazar, P.; Almanza-Robles, J. M.; Cortés-Hernández, D. A.; Escobedo-Bocardo, J. C.

doi:2022.59.6.895

J. Korean Ceram. Soc. > Volume 59(6); 2022 > Article

Original Article

Journal of the Korean Ceramic Society 2022;59(6): 895-902.
doi: https://doi.org/10.1007/s43207-022-00228-7

Thermal shock resistance of mullite/Sr-celsian/zirconia composites

P. Rodríguez-Salazar, J. M. Almanza-Robles

, D. A. Cortés-Hernández, J. C. Escobedo-Bocardo

Centro de Investigación Y de Estudios Avanzados del IPN Unidad Saltillo , Parque Industrial Saltillo-Ramos Arizpe, Ave. Industria Metalúrgica 1062, 25900 Ramos Arizpe, Coahuila, México

Correspondence

J. M. Almanza-Robles ,Email: manuel.almanza@cinvestav.edu.mx

Received: March 6, 2022; Revised: June 7, 2022 Accepted: June 28, 2022. Published online: July 18, 2022.

ABSTRACT

The thermal shock resistance of novel mullite / Sr-celsian / zirconia composites was studied. The effect of the Sr-celsian (15, 20, 25 wt.%) and ZrO₂ (5, 15, 25 wt.%) amounts on the thermal shock resistance, was evaluated. The composites were obtained at 1450 °C. Thermal shock resistance was performed by heating samples up to a selected temperature (∆T = 200–1000 °C) and then suddenly immersed in water. After testing, the bending strength was evaluated and the results were statistically analyzed using Minitab with a confidence level of 0.05. Pareto charts showed that Sr-celsian and zirconia content have the highest influence on flexural strength after thermal shock. The highest thermal shock resistance was obtained for the composites with the highest amount of zirconia and Sr-celsian. Most of the composites showed a decrease in strength of around 75%. The strength of the composites with 20 or 25 wt.% of celsian and 25 wt.% zirconia increased at ∆T of 1000 °C. The Pareto chart for these composites showed that zirconia has the highest effect on strength. A change in expansion is shown between 800 and 900 °C, indicating the transformation of monoclinic to tetragonal zirconia. This transformation generates microcracks that deflect cracks generated during thermal stress. Also, residual stresses are generated during cooling which plays a role in absorbing the energy of a generated crack. The strontium celsian forms an interlocked microstructure that improves strength. These composites are promising materials for applications in which sudden and extreme temperature changes occur.

Key words: Composites · Thermal shock · Mullite · Zirconia · Celsian