Characterisation of biscuit fired bone china body microstructure. Part I: XRD and SEM of crystalline phases

As a ceramic material bone china is a highly specialised product and is the basis of the worldʹs most attractive and expensive types of tableware, mainly due to its translucency, whiteness, bright glaze, decoration quality, and high strength. Despite numerous studies on bone china made by several authors over many years, insufficient is known even today about the chemical reactions and physical processes taking place between the various raw materials which make up the body, during biscuit firing. As a result, there is still controversy about the formation and chemistry of its constituent phases, particularly the glassy matrix phase. In this paper, part of an extended study, the biscuit firing process and the resultant microstructure of the bone china body, studied using a combination of techniques such as X-ray diffraction (XRD) and scanning electron microscopy (SEM), is reported. It is clearly shown that fired bone china body consists of crystals of anorthite, β-TCP, and also a small amount of quartz, rather unevenly dispersed in a complex glassy matrix phase.