| 摘要 |
PURPOSE:To obtain a piezoelectric vibrator which is lessened in number of component parts, cost, and size and improved in performance by a method wherein a region of the vibrator is formed into a porous structure or a region of the porous vibrator is made different from the other region in porosity, and the regions are made to have different resonant frequencies respectively. CONSTITUTION:A molding die 4 composed of an outer cylinder 5 and a boundary cylinder 6 which serves as a partitioning is used to form a burned body 1. For instance, only lead zirconate titanate is filled into the inside 2a of the boundary cylinder 6, An intermediate section 3a between the outer cylinder 2 and the boundary cylinder 6 is filled with lead zirconate titanate mixed with methacryl powder. The boundary cylinder 6 is removed from the molding die 4, and the die 4 is pressed to obtain a molded body. The molded body is kept heated by an electric oven. Then, methacryl powder dissipates by evaporation. The molded body is furthermore burned, whereby a lead zirconate titanate sintered body 1, which is composed of an inner pillar part 2 of a dense lead zirconate titanate sintered body and an outer cylinder part 3 of a porous lead zirconate titanate structure of porosity of 30%, can be obtained. Furthermore, the sintered body 1 is abraded and then subjected to a known polarization treatment. |
