CRYSTALLIZED GLASS AND ITS MANUFACTURING METHOD

PROBLEM TO BE SOLVED: To provide a low expansion crystallized glass of a milk white color or white color having excellent light diffusion characteristics, a crystallized glass member and their manufacturing method. SOLUTION: The crystallized glass contains each component of 50-62% SiO2, 22-26% Al2O3, 3-5% Li2O by mass%, an average crystal particle diameter of a crystalline phase is more than 100 nm and an average line expansion coefficient is ≤30×10-7/°C in a temperature range of 0 to 50°C. The manufacturing method contains a process for melting a glass raw material, a process for forming the molten glass, a process for gradually cooling the formed glass, a process for subjecting a first heat treatment for 0.1-200 hr at 650-750°C after gradual cooling and a second heat treatment for 0.1-50 hr at 800-1,000°C after the first heat treatment. COPYRIGHT: (C)2006,JPO&NCIPI