Study of sintering behavior of PAN–PZT using dilatometry and co-relation with piezoelectric properties

The sintering behavior of Pb(Al0.5Nb0.5)O3–Pb(Zr0.52Ti0.48)O3 (PAN–PZT) ceramics was investigated. The sintering process of PAN–PZT was divided into four stages based on the amount of in-situ linear shrinkage: (Stage 1) initial stage at sintering temperature RT≤Ts≤ to 770 °C, (Stage 2) perovskite formation stage at 770≤Ts≤990 °C, (Stage 3) densification stage at 990≤Ts≤1265 °C and (Stage 4) Pb-loss stage at Ts>1265 °C. During stage 1, heating of PAN–PZT compact did not cause structural changes except the thermal expansion. During stage 2, the PZT-perovskite structure was formed by rearrangement of crystals. During stage 3, the specimen was rapidly densified with two peaks of strain rate. During stage 4, Pb was volatilized and this loss resulted in sudden increase of shrinkage. On analyzing the sintering stages, the optimized sintering conditions were considered as 1250 °C just before of Pb-loss stage. The effects of Ts on the crystal structure, microstructure and the piezoelectric performance were analyzed and documented.