| 摘要 |
PROBLEM TO BE SOLVED: To enhance mechanical strength by specifying the mean grain size of the perovskite type crystal particle in a piezoelectric ceramic containing Pb, Zr, Ti, Zn, Sb and Nb. SOLUTION: Mean grain size of perovskite type crystal particle is set in the range of 1.5-15 μm. Since the crystallinity of ceramic can be sustained at a high level even if the firing temperature is lowered, the mean grain size can be controlled to a low level of 1.5-15 μm and mechanical strength can be enhanced while sustaining the piezoelectric characteristics. The piezoelectric characteristics degrades when the mean grain size is smaller than 1.5 μm, and the mechanical strength degrades when the mean grain size is larger than 15 μm. Preferably, the mean grain size of perovskite type crystal particle is set in the range of 2-5 μm in order to enhance the mechanical strength while preventing degradation of the piezoelectric characteristics. |
