| 摘要 |
PURPOSE:To reduce thermal conductivity and expansibility by calcining a mixture of a compound of a group IIa element with a compound of group IIIa element of the periodic table, a Zr compound and ammonium phosphate and then sintering the calcined mixture. CONSTITUTION:A compound of a group IIa element of the periodic table is mixed with a compound of a group IIIa element of the periodic table, a Zr compound and ammonium phosphate so that the molar ratio of the group IIa element, group IIIa element, Zr and P satisfy the formula (Group IIa)1+a(group IIIa)2aZr4-2aP6-b (0<1<0.2; O<b<1.0). Thereby, a mixture is obtained and calcined in an oxidizing atmosphere at 600-1200 deg.C to form a solid solution, which is then sintered in an oxidizing atmosphere at 1400-1600 deg.C to afford the objective phosphoric acid-based sintered compact, composed of a microstructure of <=10% porosity and <=2mum average grain diameter and having <=3W/m.k thermal conductivity, -1.5X10<-6> to 1.5X10<-6>/ deg.C thermal expansion coefficient at 40-1200 deg.C and >=50kg/mm<2> strength. |
