Publication :


Title:

The impact of heat treatment on the microstructure of a clay ceramic and its thermal and mechanical properties

Authors: P.-M. Nigay, A. Nzihou and T. Cutard
Year: 2017
Journal: Ceramics International.
Volume: 43, Pages: 1747-1754

DOI: 10.1016/j.ceramint.2016.10.084
Référencé ISI Web Of Science

Abstract:
This paper presents the results of an experimental study on the microstructure, the thermal and the mechanical properties of a clay-based ceramic used in building applications. The X-ray tomography analysis showed a layered microstructure of clay with 200 μm sheets of porosity after the extrusion process. The gas release from the dehydration, dehydroxylation and decarbonation induced a 7 vol% formation of porosity during the heat treatment of the clay-based ceramic up to 850 °C. The porosity increase and the development of metakaolin led to a 38% decrease in the thermal conductivity. On the other hand, the Young's modulus of the clay-based ceramic was conserved due to the formation of smaller pores than the 200 μm sheets of porosity. The densification and the crystallization of amorphous phases also led to a 110% increase of the Young's modulus from 850 °C to 1050 °C. The Young's modulus of the clay-based ceramic was only decreased by the β→α quartz inversion of the cooling due to sand addition. Hence, this study provided a useful insight into how the microstructure of fired clay bricks can be specifically transformed by the porosity during the heat treatment to control the thermal and mechanical properties.

Bibtex citation :
@article{Nigay2017,
Author={Nigay, P.-M. and Nzihou, A. and Cutard, T.},
Title={The impact of heat treatment on the microstructure of a clay ceramic and its thermal and mechanical properties},
Journal={Ceramics International},
Volume={43},
Number={},
Pages={1747-1754},
Year={2017}}


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