備前焼模様「緋(火)襷」の材料科学的研究 Scientific Study of "Hidasuki" Pattern on Bizen Stoneware
The microstructure and formation process of Hidasuki, a characteristic reddish pattern on traditional Japanese unglazed stoneware called Bizen, was studied through model experiments. Pellets of the Bizen clay mined at Bizen-shi/Okayama pref. were heated to 1250°C with and without rice straw and then cooled at different rates. A reddish color pattern appeared for relatively slowly cooled samples when rice straw was present. Owing to the presence of potassium in the rice straw, mullite (3(Al, Fe)<SUB>2</SUB>O<SUB>3</SUB>·2SiO<SUB>2</SUB>), a major phase formed in the absence of rice straw, was replaced by corundum (α-Al<SUB>2</SUB>O<SUB>3</SUB>), hematite (α-Fe<SUB>2</SUB>O<SUB>3</SUB>), and others in the surface region of about 50μm in depth. The corundum precipitated as hexagonal plate-like crystals, and on the edges of these crystals the hematite grew epitaxially. The growth continued so that the primary corundum crystals were wholly covered by hematite to form a specific single crystalline α-Fe<SUB>2</SUB>O<SUB>3</SUB>/α-Al<SUB>2</SUB>O<SUB>3</SUB>/α-Fe<SUB>2</SUB>O<SUB>3</SUB> structure.
粉体および粉末冶金 54(2), 75-80, 2007-02-15
Japan Society of Powder and Powder Metallurgy