The mechanism of flint red and its relationship with celadon glaze color

Flint red is the red narrow band found in the exposed body of porcelain, which is a common phenomenon in ancient porcelain. Some experts believe that flint red is an important symbol for judging the age of ancient ceramics. This paper takes sky-green Yaozhou porcelain as the example, and successfully fired samples of Yaozhou porcelain with flint red, and reveals the formation mechanism of flint red. This study uses XRF (X-ray fluorescence), XRD (X-ray diffraction), SEM (Scanning electron microscope) and non-contact imaging spectrophotometer analysis to discover for the first time that during the reduction process, the iron of the glaze migrates to the body with the melt in the gas phase, and the flint red is a hematite thin film formed on the body after being oxidized for the second time during the cooling process of the kiln. The influence of the redox atmosphere and placement mode of ceramics on flint red were studied. The relationship between flint red and the degree of color reduction of celadon glaze surface was discussed. In addition, the growth method of hematite film is enlightening for the preparation of anticorrosive coatings on steel products, and has broad application prospects.

Automated summary

This paper investigates the formation mechanism of flint red and its relationship with the age of ceramics and the reduction degree of glaze surface. It is found that flint red is a hematite thin film formed on the body when iron migrates from the glaze during the reduction process. This study provides insights for the preparation of anticorrosive coatings on steel products.