Colour development of red perovskite pigment Y(Al,Cr)O3 in various ceramic applications

Ceramic pigments based on the perovskite structure develop a promising red hue and furthermore present no environmental or health problems. Pigment colouring efficiency was tested in different ceramic applications, both in the body and in glazes. Final products, with variations in both maximum firing temperature and soaking time, were characterised by colorimetry. The investigation focused on the factors and mechanism influencing perovskite dissolution by calculating phase compositions of different ceramic matrices and observing pigment microstructure. Pigment powders were also characterised by structural analysis and spectroscopy. Pigment dissolution was only slightly affected by the firing cycle, mostly being governed by the amount and chemical composition of the liquid phase. In particular, the larger the content of chemically aggressive components such as calcium, magnesium, zinc and lead oxides, the stronger and faster the pigment dissolution