Sanitary-ware vitreous body characterization method by optical microscopy, elemental maps, image processing and X-ray powder diffraction

The present investigation deals with a characterization method for fired body (cast piece) from a standard sanitary-ware industrial cycle, relying upon data mainly from optical/electron microscopy and chemical mapping. Image processing techniques have been used to reconstruct the phase-distribution throughout the body, so as to provide a phase-arrangement-sensitive description of the crystalline and amorphous components. The results so attained are compared with those from classical X-ray powder diffraction in terms of total phase-contents. The amorphous phase-content and its distribution can be determined by optical microscopy, and the modest level of precision of the phase quantification is improvable by accounting for the occurrence of voids. Residual quartz is identified by means of the backscattered electron contrast differences in images, and thereby its morphologic properties and amount are determined. The use of elemental X-ray maps allows one to attain a description of the local composition and, on the basis of some assumptions, to quantify microcrystalline mullite and also discriminating between primary versus secondary mullite.