Study On Fabrication, Structure And Properties Of PZT5/Epoxy Resin 1-3 Composites

1-3 piezoelectric composites combine high piezoelectric properties of piezoelectric ceramic and flexibility of polymer. Compared with pure ceramic or piezoelectric polymer, 1-3 piezoelectric composites have more marks, such as higher piezoelectric conatant, larger mechanical-electronical coupling coefficient, lower mechanical quanity factor and smaller acoustic impedance. They are suitable for transducers with high sencsitivity, wide bend and narrow pulse, which have been widely used in medical ultrasonic, nondestructive test and hydrophone.In this article, the development of 1-3 composites was discussed. PZT5 fibers were fabricated by viscous polymer processing (VPP). 1-3 piezoelectric composites were prepared by arranging PZT5 fibers and casting epoxy resin. Based on its use for medical ultrsonic transducer, the influences of procedure, poling, ceramic volume fraction and aspect ratio on piezoelectric properties, dielectric properties, ferroelectric properties and acoustic impedance were studied. And the rules of 1-3 composites were consistent with the composite theory, which were useful for their applications and developments.(1) PZT5 ceramic fibers were fabricated by viscous polymer processing (VPP). The affects of organic and sintering condition on fiber structures and properties were analyzed. The optimized composition of lurry was 30 vs. 4 vs. 1 (PZT5 vs. PVA binder vs. glycerine, wt%), and the best sintering condition was done at 1280 °C for 4 h. The fiber structure was dense, and the crystal size was uniform, about 2-5 μm.(2) To the round section PZT5 fibers, the hygroscopic coefficient W_u, apparent porosity P_a and bulk density ρ_y were 0.45%, 0.44% and 7.89 g/cm~3, respectively. The ultimate tensile strength (U.T.S.) reached 24.88 MPa. The remnant polarization P_r and coercive field E_c were 41.40 μC/cm~2 and 1.10 kV/mm, respectively. The square section PZT5 fibers were fabricated with bulk density ρ_v of 7.91 g/cm~3. The U.T.S. was 23.97 MPa. While the value of P_r and E_c were 41.68 μC/cm~2 and 1.10 kV/mm, respectively.(3) With study on curing technique of epoxy resin, it was found that the structure of epoxy resin was tight and almost had no pore when the curing agent...