The Improvement Of Preparation And Performance Of The Piezoelectric Composite With Spiral Structure

Piezoelectric composites possess the excellent piezoelectric properties，flexibilityand low dielectric constant. What’s more, the low acoustic impedance Z and goodhydrostatic properties can be obtained by the addition of epoxy resin. Theseadvantages make piezoelectric composites a candidate for sensor and transducerapplications.A novel0.25PZN-0.75PLZT ceramic/epoxy resin composite based on a spiralceramic skeleton was fabricated by a roll forming-curling method in this paper. Thespecial structure would not only promote the level of polarization effectively, but alsomake the preparation easier than1-3composites. In addition, the performance of thecomposites is comparables to that of1-3composites, and the roll forming-curlingmethod is cheaper and easier.The influence of the volume fraction of ceramics, preparation process, sinteringtemperature and polarization conditions on piezoelectric properties, dielectricproperties, acoustic performance of the composites is studied. The results are asfollows:When sintered at1220℃, the composite with spiral structure will get optimalperformance: the density is7.612g/cm³, gh=104.567×10^-15Vm/N, FOM=23.4×10^-12m²/N. The epoxy resin K9530is more suitable to make the composites, because itwill induce lower stresses than other resins. Meanwhile, the acoustic performance ofthe composites is better. As the0.25PZN-0.75PLZT ceramic volume fraction was40%, the composite got the optimal properties: kt=61%, r=988andFOM=37.5×10^-12m²/N. The interface between the ceramic rings and epoxy resin wasgood when the silane coupling reagent KH560was used, and the dielectric breakdownstrength of these composites was improved to3KV/mm. The optimized pollingcondition for the composites with spiral structure was at time of20min, temperatureof80℃, and polarization field strength of2KV/mm.