Investigation of the use of halloysite in ceramic glaze

Artistic glazes are kinds of inorganic compositions which are generally used to protect, strengthen, coloring, and decoration of ceramic arts. Crawling glazes, are defined as an artistic vitreous covering that gather on the surface of ceramic artworks in the form of veins and islands due to the surface tensions. Although this characteristic is normally considered as a glaze defect in the industrial ceramics, it is known as an artistic decoration in types of ceramic artworks. In this thesis, it was aimed to develop double, triple, and quadruple crawling glaze recipes using halloysite clay minerals. The developed glaze samples were applied to whiteware and porcelain ceramic bodies which were previously biscuit fired at 980℃ by pouring method, and finally fired at 1000, 1050, and 1100 ℃ in an electric furnace. İn the second step the addition of 0.1%-0.4% wt.% of coloring metal oxides were investigated in some selected recipes. It was determined that the coloring intensity increased due to the tubular structure of halloysite. At the final stage, the optimum glaze formulations were tested on some special ceramic artworks by the same method. The whole results of the study revealed that the halloysite clay mineral can be successfully used in the production of crawling artistic glazes with enhanced coloring characteristics.