Plasma Spraying of Silica-Rich Calcined Clay Shale

0427951 - ÚFP 2015 RIV US eng J - Journal Article
Dubský, Jiří - Chráska, Tomáš - Pala, Zdeněk - Nevrlá, Barbara - Chráska, Pavel
Plasma Spraying of Silica-Rich Calcined Clay Shale.
Journal of Thermal Spray Technology. Roč. 23, č. 4 (2014), s. 732-741. ISSN 1059-9630. E-ISSN 1544-1016
R&D Projects: GA ČR GAP107/12/1922; GA ČR(CZ) GAP108/12/1872
Institutional support: RVO:61389021
Keywords : clay shale * crystallinity * grain size * mullite * water stabilized plasma * x-ray diffraction
Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass
Impact factor: 1.344, year: 2014
http://link.springer.com/article/10.1007%2Fs11666-014-0076-3

Silica-rich clay shale is a viable candidate for replacement of mullite in many applications, especially when outstanding refractoriness and chemical resistance to various agents is desirable. In this contribution, instead of the commonly used synthetic mullite feedstock, the thermal stability of inexpensive calcinated natural raw clay shale sprayed using water stabilized plasma system is reviewed. Phase stability and phase changes at elevated temperatures up to 1500 °C were studied by an array of experimental techniques ranging from measurements of thermal conductivity and the heat flow as functions of temperature, scanning electron microscopy, X-ray diffraction (XRD) of the annealed samples and in-situ high temperature XRD. The mostly amorphous as-sprayed coatings with less than 10 wt. % of mullite are temperature stable up to 800 °C and rapid crystallization occurs between 920 and 940°C. Performed analyses gave evidence about the increase of mullite grain sizes for temperatures
Permanent Link: http://hdl.handle.net/11104/0233393