| 摘要 |
PURPOSE:To eliminate the generation of cracks at the time of baking, by molding mixture of raw material calcined powder of piezoelectric ceramic and paraffine particles, and baking the molded object. CONSTITUTION:A specified amount of high purity lead monoxide, (PbO, purity 99.9%), titanium dioxide (TiO2, purity 99.9%), zirconium oxide (ZrO2, the same purity), and other additive are weighed, and mixed together with pure water for about 20 hours by using a pot mill. The mixture is dehydrated, dried, and calcined at 800-900 deg.C for 2-10 hours, thereby obtaining a calcined material of PZT. Water is added to the calcined material, and it is grinded, dehydrated, and dried, thereby forming PZT calcined powder 11. Paraffine particles (spherical paraffine) 12 of 20 (weight ratio) whose spherical diameter is about 900mum are added, as void forming agent, to the PZT calcined powder 11 of 100 (weight ratio), and mixed. The mixture is contained in a metal mold, and molded by applying pressure. The temperature of the molded object is increased in the air at a rising speed of 100 deg.C/hour, and the object is baked at 1200-1300 deg.C for 2 hours, thereby forming voids 22. Thus PZT ceramic 21 is obtained. |
