Effects of 30B2O3–25Bi2O3–45CdO glass addition on the sintering of 12Pb(Ni1/3 Sb2/3)O3–40PbZrO3–48PbTiO3 piezoelectric ceramics

Effects of 30B2O3–25Bi2O3–45CdO (BBC for short) glass addition on the sintering of 12Pb(Ni1/3Sb2/3)O3–40PbZrO3–48PbTiO3 (12PNS–40PZ–48PT) piezoelectric ceramics have been investigated using PbO, ZrO2, TiO2, NiO, Sb2O3, B2O3, Bi2O3 and CdO powders as starting materials. Using calcined 12PNS–40PZ–48PT powders with BBC glass concentration from 1.0 to 5.0 wt.% and sintering at 925°C for 2 h, the X-ray diffraction patterns show that the addition of 1.0 wt.% BBC glass results in 100% tetragonal when compared with 2.0–5.0 wt.% BBC glass addition which causes the coexistence of both tetragonal and rhombohedral phases. On the other hand, when sintered at 950°C 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 the 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 piezoelectric ceramic can be reduced lower than 1000°C 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 wt.% BBC glass when sintered at 925°C for 2 h. After sintering at 925°C for 2 h, the planar coupling coefficient (Kp) value decreases from 0.51 to 0.30 as the of BBC glass concentration increases from 2.0 to 5.0 wt.%. The mechanical quality coefficient (Qm) increases as the BBC glass concentration increases from 2.0 to 4.0 wt.%.