摘要 |
PROBLEM TO BE SOLVED: To obtain a dense piezoelectric porcelain compsn. having high density by preparing a specified compsn. containing Pb, Zn, Nb, Ti, Zr, O. SOLUTION: This porcelain compsn. essentially consists of a compd. expressed by formula I and is prepared by adding Pb3 (PO4 )2 by 0.01-0.5wt.% to a compsn. included in the polygonal region in a triangular coordinate system having apexes representing formula II, PbTiO3 and PbZrO3 as shown in the figure. The polygonal region is defined by points A, B, C, D, E, wherein X+Y+Z=100(mol%), X=1.0, Y=62.5, Z=36.5 at the point (A), X=12.5, Y=75.0, Z=12.5 at the point (B), X=50.0, Y=37.5, Z=12.5 at the point (C), X=50.0, Y=12.5, Z=37.5 at the point (D), X=1.0, Y=12.5, Z=86.5 at the point (E). The obtd. piezoelectric porcelain compsn. significantly increases the density of a sintered body and improves piezoelectricity. It is because when the piezoelectric porcelain compsn. is sintered, Pb3 (PO4 )2 reacts with the compsn. to form a liquid phase to improve the sintering property. |