铁铜色釉的呈色特性及窑变机理

The copper red, purple, green blue glazes and the fancy glazes were prepared with copper and iron oxides as colorants via the change of the fundamental ingredients at the same firing schedule. The effects of physical/chemical principle, base glaze compositions and firing temperature of iron and copper coloring glaze on the coloring mechanism were investigated by triangular batching method, scanning electron microscopy, energy dispersive spectroscopy and CIE-L*a*b* color-measurement, respectively. The results indicate that the more red color glazes have lower SiO₂ and higher alkali metal and alkaline earth metal oxides contents rather than those of the more blue color glazes under the same firing condition. Besides, a difference between copper red and red purple glazes merely appears due to the later ingredient containing little phosphate anion. When the Ca₃(PO₄)₂ is introduced into the glaze, the micron-/nano-sized and short-range ordered phase separation structures form the structural color, while accumulated Fe₂O₃ in micron-sized-phase decomposes to Fe²⁺ and bubbles, forming blue stains and/or other color flowers. In addition, iron and copper coloring elements have a variety of coloring characteristics. The adjustment of process parameters and the basic components can control the color and hue of glazes accordingly, resulting in the fambe. The multiple chemical colors coupling the micron-/nano-sized structure colors promote the formation of complex and changeable glaze colors and increase the fambe and coloring specificity as well.