摘要 |
PROBLEM TO BE SOLVED: To easily provide ceramics which are lightweight with low thermal expansion and stable with high rigidity and which does not require special heat treatment to form a solid solution. SOLUTION: The ceramics consist of a sintered body containing such a crystalline phase that contains Mg, Al and Si and shows two main diffraction peaks at 24.6 to 24.8 deg. and 24.7 to 24.9 deg. of 2θ by the X-ray diffraction analysis. The ceramics have <=3×10<-6> / deg.C coefficient of thermal expansion at 0 to 25 deg.C, >=150 GPa Young's modulus, <=3.1 specific gravity and <=0.1% water absorptivity. |