| 摘要 |
PURPOSE:To prevent the change of a composition and the lowering of sintered density by holding a dummy element having the same composition as a molded element and thickness of one fifth or smaller of the molded element between the molded element having a PZT group composition and thickness of 1mm or more and a zirconia bottom plate. CONSTITUTION:Two molded elements 1 having a PZT composition and thickness of 1mm or larger are superposed, zirconia bottom plates 2 are mounted to upper and lower sections one by one, and dummy elements 3 made up of the same elements as the molded elements 1 and having thickness of one fifth or smaller of the elements 1 are disposed among the elements and the bottom plates. The temperatures of the elements 1 are elevated to 1260 deg.C from the normal temperature, and held for one hr and sintered. PbO is evaporated from the dummy elements during that time, the evaporation of PbO from the surfaces of the sintered elements is inhibited, and the diffusion reaction of materials of a different kind is not generated because the sintered elements and the dummy elements are brought into contact mutually. Since the thickness of the dummy elements is brought to one fifth or smaller, the molded elements are not overloaded. According to the constitution, the generation of cracks is prevented on sintering, thus improving the state of the surface. |
