| 3-3 piezocomposites have been used in ultrasonic testing and other fields due to the prope-rties of low density, high hydrostatic figures of merit, low sound velocity, which leads to redu-ceed acoustic impedance and enhanced coupling with water. Based on former literatures, present situation and trend in development, with PZT as ceramic phase, graphite as second phase, a trim, controlled 3-3 pores piezocomposite has been prepared by tape-casting and stack method after all the graphite oxidized, after polarization 3-3 piezocomposite got piezo-function.Experimentation is divided into two sections:preparation and test. Preparation focus on factors of tape-casting, sinter and polarization. It has been decided that bolling time:48h, volu-me frac-tion of powder and binder 1:2, blinder gap 500μm. Sinter includes binder removal and fire. Binder removal has a curve of 3℃/min from room temperature to 200℃,1℃/min from 200℃to 600℃. Keep every one hour at 200℃,400℃,600℃. The fire needs only a litter time form 600℃to 1280℃and keep warm about 90min. Binder removal needs much of oxygen but fire needs to be bury-sinter. Polarization can be show excellent under a situation of 120℃, 15min,3kV/mm.Processing parameter during every step are discussed. Under the situation of L1:L2=2, the porosity included 21.4%-57.9%, the same situation is that when L1:L2=1, the porosity is 16.4%-43.9%, when L,:L2=0.5, the porosity is 28.8%-65.1%. Test show that with porosity added, permittivity, d33 reduced, but gh added. dh,gh have a max with porosity 20%-45%. When keep porosity unchanged, all the properties added with L1:L2 added. |
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