Study On Fabrication And Properties Of PMnS-PZN-PZT Piezoelectric Ceramic Fiber

Piezoelectric materials are being extended in smart structures for its positive-inverse piezoelectric effect to adjust deformation or electrical output signal initiatively. Piezoelectric fiber has more merits, such as higher piezoelectric constant, larger mechanical-electronical coupling coefficient, and better anisotropism, and it could be used to composite with polymer for medical ultrasonic, underwater transducer or self-adoption surface of aviation, spaceflight applicationIn this article, PMnS-PZN-PZT fibers were fabricated by viscous polymer processing (VPP),1-3 piezoelectric composites were prepared by arranging fibers and casting epoxy resin. The preparation process of plastic ceramic mud and piezoelectric fiber and the conditions of epoxy resin curing are studied. The influences of the resin on the properties of piezoelectric fiber and the aspect ratio of fiber on the structure, properties and vibration patterns of composite material were discussed. Specific work and conclusions are as follows:(1) Piezoelectric materials with better properties were prepared by VPP for PMnS-PZN-PZT piezoelectric fibers. The influence of organic content of the mud compound on the preparation of the fiber and the sintering conditions on the structure and performance of fibers were analyzed. The results show that the optimal formula for the mud:the dosage of polyvinyl alcohol in the ceramic powder is 0.56 wt%, glycerol addition is 3.33 wt%, the value of zeta potential of ceramic mud is the largest. The optimum sintering temperature of fiber is 1240℃, holding for 6h. The ultimate tensile strength of fiber is to 16.5 MPa with brittle fracture and perovskite phase, and the grains combined with tight with uniform size. the piezoelectric fiber with high density and high mechanical strength could be prepared by the method of VPP for the green fiber presenting plastic.(2) Restrained state on the ferroelectric properties of fiber is studied. The remnant polarization and coercive field of piezoelectric fibers in the free state were 85.4μC/cm2 and 8.5 kV/cm respectively, while the remnant polarization and coercive field of fibers in restrained state were 39.2μC/cm2 and 15.0 kV/cm respectively. So the restrained state has a huge impact on ferroelectric properties of the fibers. The restrained state could reduce the leakage current of the surface of fiber and free deformation from the result of leakage current test. (3) The curing process and the polarization conditions of composites made by the way of arranging-casting were studied, and the effect of fiber aspect ratio (t/d) on the piezoelectric properties of composite materials was analyzed. The g33 andκt/κp of composites were higher than the ceramic bulk and fiber, and the 1-3 composite has better anisotropic. The ratio (t/d) of fiber has a large impact on the piezoelectric and dielectric properties of composite. When t/d=2, the composite has the best properties with single thickness vibration mode.