Piezoelectric composite material

摘要

A high dh piezoelectric composite material useful for utilization for hydrophones is disclosed which includes a matrix of an organic polymeric material and two different inorganic piezoelectric powders dispersed in the matrix. One of the piezoelectric powders has a large ¦d31/d33¦ value, such as lead titanate zirconate, and the other piezoelecctric powder has a low ¦d31/d33¦ value, such as lead titanate. The average particle size of one of the two piezoelectric powders is at least two times that of the other. The total amount of the two piezoelectric powders is 65-75% by volume based on the total volume of the matrix and the two piezoelectric powder. The volume ratio of the high ¦d31/d33¦ piezoelectric powder to the low ¦d31/d33¦ piezoelectric powder is in the range of 3:2 to 9:1.