| 摘要 |
A low thermal expansion ceramic composition having a predominant Al2TiO5 phase along with zirconium titanate and zirconia phases. The final overall ceramic composition after firing has a low thermal expansion between 24-1000.degree.C of not greater than 1.5x10-6.degree.C-1 and a thermal stability in air such that (a) upon heating to 1200.degree.C for at least 4 hours there is substantially no decomposition of the Al2TiO5 phase to rutile or alumina as measured by X-ray diffraction, (b) physical growth after thermal cycling between 200. and 1150.degree.C for 300 cycles does not exceed 1.5%, and (c) the composition maintains a low average thermal expansion between 24-1000.degree.C of not greater than 1.5x10-6.degree.C-1 after the isothermal heating or cycling conditions. The composition is preferably made by forming a mixture of the equivalent of 50-90 volume percent Al2TiO5 or a solid solution having a substantial amount of Al2TiO5 in the solid solution, and zirconium titanate and then heating the mixture at a temperature of 1250.degree.C or higher. |
