FABRICATION, CHARACTERIZATION AND APPLICATIONS OF PIEZOELECTRIC FIBERS WITH METAL CORE

摘要

Fabricauon, characterization and applications of the Pb(Nb,Ni)O3-Pb(Zr. Ti)O3 (PNN-PZT)piezoelectric ceramic fibers with a metal core are introdnced. The green fbers of about 300μm in diameter were fabricated by extruding a mixture of PNN-PZT powder and crganic solvent together with a 50 μm Pt core. Fibers of 250 μm in diameter and a few cenumeters long were obtained after sintered at 1200°C. The ferroelectricity and piezoelectrcity of a single fiber was confirmed. The polanization versus electric field relationship was measured using a Radiant RT-6000 and the result exhibits the typical ferroelectricity of the PNN-PZT material. The strain versus electric field relationship also shows the typical hysteresis of piezcelectric materials due to the d31 effect. In order to measure its electromechanical coupling factor and piezoelectric constant, an analysis of the first resonance mode of the piezoelectric fiber with metal core was caried. The effect of the metal core was evaluated through the calculation of the electromechanical coupling factor of the whole fiber. The model was simplifed and a characrerizaticn procedure for the piezoelectric constant of the ceramicsin the fiber was obtained. An applications of the piezoelectric fibers with metal core in sensors for impact identifcation of a composite board is also introduced.