Effects of 30B(2)O(3)-25Bi(2)O(3)-45CdO glass addition on the sintering of12Pb(Ni-1/3 Sb-2/3)O-3-40PbZrO(3)-48PbTiO(3) piezoelectric ceramics

Effects of 30B(2)O(3)-25Bi(2)O(3)-45CdO (BBC for short) glass addition on t he sintering of 12Pb(Ni1/3Sb2/3)O-3-4OPbZTO(3)-48PbTiO(3) (12PNS-40PZ-48PT) piezoelectric ceramics have been investigated using PbO, ZrO2, TiO2, NiO, Sb2O3, B2O3, Bi2O3 and CdO powders as starting materials. Using calcined 12 PNS-40PZ-48PT powders with BBC glass concentration from 1.0 to 5.0 wt.% and sintering at 925 degreesC for 7 h, the X-ray diffraction patterns show tha t the addition of 1.0 wt.% BBC glass results in 100% tetragonal when compar ed with 2.0-5.0 wt.% BBC glass addition which causes the coexistence of bot h tetragonal and rhombohedral phases. On the other hand, when sintered at 9 50 degreesC for 2 h, for the addition of 1.0 wt.% BBC glass the crystalline phase appears to be largely reombohedral, and an increased tendency for th e evidence of the parasitic phase of pyrochlore for the addition of 2.0-5.0 wt.% BBC glass. The sintering temperature of a 12PNS-40PZ-48PT piezoelectr ic ceramic can be reduced lower than 1000 degreesC by the addition of 1.0-5 .0 wt.% BBC glass and a density of 97.5% of the theoretical is obtained for the compact containing 2.0 w.t.% BBC glass when sintered at 925 degreesC f or 2 h. After sintering at 925 degreesC for 2 h, the planar coupling coeffi cient (K-p) value decreases from 0.51 to 0.30 as the of BBC glass concentra tion increases from 2.0 to 5.0 wt.%, The mechanical quality coefficient (i. e.) increases as the BBC glass concentration increases from 2.0 to 4.0 wt.% . (C) 2001 Elsevier Science Ltd. All rights reserved.