Patent ID: 7067085

Claim:
A method for the production of a black low thermal expansion high specific rigidity ceramic sintered body, comprising: forming the sintered body in an atmosphere of a non-oxidizing gas at a temperature in the range of 1200–1500° C., said black low thermal expansion high specific rigidity ceramic sintered body, comprising: having a thermal expansion coefficient of not more than 0.6×10 −6 /° C. in absolute value at room temperature, a modulus of elasticity (Young's modulus) of not less than 100 GPa, a specific rigidity (Young's modulus/specific gravity) of not less than 40 GPa·cm 3 /g, and assuming a black tone, said black low thermal expansion high specific rigidity ceramic sintered body having a chemical composition comprising: 8.0–17.2 mass % of MgO, 22.0–38.0 mass % of Al 2 O 3 , 49.5–65.0 mass % of SiO 2 , a total of 0.1–2 mass % of one or more transition elements as reduced to oxides, 0–2.5 mass % of Li 2 O, and having the mass ratios satisfy the relationships of (SiO 2 −8×Li 2 O)/MgO≧3.0 and (SiO 2 −8×Li 2 O)/Al 2 O 3 ≧1.2.