| 摘要 |
PROBLEM TO BE SOLVED: To obtain a ceramic material having high sintering density, strength stability under low oxygen partial pressure and same coefft. of thermal expansion as that of YSZ by substituting Sr, Al and Co for a part of La and Cr sites in LaCrO3 and controlling the substitution amt. of each metal element and atomic proportion of B and A sites in the perovskite crystal structure ABO3 . SOLUTION: The ceramic sintered body has a perovskite crystalline structure expressed by the formula and has >94% relative density, >=15 kgf/mm<2> bending strength at room temp. and the same bending strength at room temp. after the body is treated in a moisture atmosphere at 10<-18> atm oxygen partial pressure at 1000 deg.C for 24 hours. The sintered body has <=0.3% expansion rate of lattice volume at room temp. after the treatment, 9.8 to 11.0×10<-6> K<-1> average coefft. of thermal expansion from 30 to 1000 deg.C, and <=-20 deg.C phase transition temp. from the rhombic system to rhombohedral system. In the formula, (x), (y), (z), (a), (b) satisfy the relation of x+z>=0.06, z>=0.02, x+y+3z>=0.25, 2x+3y+5z>=0.40, x+y>=0.12 and 1.00<=b/a<=1.04. |
