Fabrication of Pb(Nb,Ni)O3-Pb(Zr,Ti)O3 Piezoelectric Ceramic Fibers by Extrusion of a Sol-Powder Mixture

Abstract

A study on the fabrication of Pb(Nb,Ni)O3-Pb(Zr,Ti)O3 (PNN-PZT) piezoelectric ceramic fibers by extrusion of a powder-sol mixture is presented. The process using extrusion of a powder-sol mixture was first applied to the fabrication of PZT fibers and its advantages were discussed in the former study. In this study, the process is applied to the fabrication of PNN-PZT fibers, and the conditions of the process, such as the viscosity adjustment of sol, the additives for suppressing hydrolysis reaction in the preparation of sol, the mixture ratio of powder and sol, and the sintering temperature, were investigated. The PNN-PZT sol functions as a binder during extrusion, but it changed into PNN-PZT crystalline during sintering so that the removal process of additives before sintering was not required. Green fibers with a diameter of about 250 mm were successfully extruded from the mixture of PNN-PZT sol and powder, with a sol to powder ratio between 1: 5 and 1: 8 (molar ratio). The microstructure, dielectric property and piezoelectric property of the fabricated fibers are investigated and compared with those of the fibers fabricated from a powder and organic binder mixture. The results show that the fibers sintered at 1200°C have good microstructure and exhibit competitive performance as the bulk material.