Glass-ceramics and method for manufacturing the same

摘要: There are provided glass-ceramics comprising, in mass %, 50-60% SiO 2 , 22-26% Al O 3 and 3-5% Li O, having an average crystal grain diameter exceeding 100 nm, linear thermal expansion coefficient of 30×10 −7 /° C. or below within a temperature range 0° to 50° These manufactured by step melting glass raw materials, forming the molten glass, annealing formed first heat treating for annealed at 650-750° 0.1 hour 200 hours, second 800-1000° 50 hours.