Two kinds of robust modified lead titanate piezoelectric ceramics were prepared with conventional solid state reaction methods, corresponding to two techniques of decreasing tetragonality and thermal expansion coefficient to reduce those crack stresses resulting from ferroelectric phase transition. Their structure, dielectric, ferroelectric and piezoelectric properties were experimentally studied in comparison for the Pb0.88Sm0.08 Ti0.98Mn0.02O3 and Pb0.6Bi 0.4(Ti0.75Zn0.15Fe 0.10)O 3 systems. © Taylor & Francis Group, LLC.

A V-shaped linear ultrasonic motor with a stator and a slider has been developed. The stator consists of two orthogonal Langevin actuators which is joined together in their ends. The Langevin actuators are symmetrical and have same first order longitudinal mode. A linear motion of the slider is generated by friction between the stator and the slider when the two first order longitudinal modes are combined. In this paper, structural dynamic design on the stator is completed with Finite Element Method(I-EM). The prototype motor is manufactured based on the design results. The operation modes of the stator and the output performances of the motor are tested. The diameter and length of the Langevin actuator are 20mm and 58mm, respectively. The mass of the stator is 290g. The first order longitudinal frequency of the Langevin actuator is 27.47 kHz (FEM simulating result) and 27.36 kHz (expermental result), respectively. The maximum driving force of the motor approaches 40N. The maximum velocity of the motor is about 100 mm/s. So the stator's operation modes are consistent with the design results, and the motor output properties have characteristics of slower velocity and stronger force.

In general, commercial PZT piezoceramics are sintered at temperature above 1200°C. Here, one low-temperature sintering technology was developed for PZT piezoceram-ics by adding perovskite-type ferroelectrics with low sintering temperature, alternative to adding non-piezoelectric low-melting glass or eutectic oxides. Through solid state reaction mechanism, very densified piezoceramics of (Pb0.95Sr0.05)(Zr0.53 Ti 0.47)O3 with 0.6PbTiO3-0.3Bi(Zn0.5Ti 0.5)O3-0.1BiFeO3 as sintering additive were obtained below 1050°C. The phase of (Pb,Bi,Sr)(Zr,Ti,Zn,Fe)O3 solid solution piezoceramics was demonstrated to be single-phased perovskite structure and the measurements of dielectric, ferroelectric and piezoelectric properties showed good piezoelectric performance equivalent to PZT-8.

Perovskite-structured Pb0.6Bi0.4(Ti 0.75Zn0.15Fe0.1)O3 ceramics was reported with high Curie temperature TC of 705°C and tetragonality of c/a = 1.10, promising for high temperature applications with large piezoelectric anisotropy. In this paper, it was experimentally demonstrated to ease poling processing and enhance piezoelectricity through substituting lead with calcium of Pb0.6-xCaxBi 0.4(Ti0.75Zn0.15Fe0.1)O 3. For the x = 0.18 sample, electromechanical coupling factor ratio of kt/kp → ∞, dielectric constant of 380, piezoelectric coefficient d33 of 80 pC/N, mechanical quality factor Qm of 50 and Curie point TC of 237°C were obtained, which exhibits better piezoelectric performance than the (Pb 0.76Ca0.24)(Ti0.96(Co0.5W 0.5)0.04)O3. The enhanced piezoelectric response was analyzed with relation to the reduction of tetragonality and Curie temperature. © 2011 Elsevier Ltd and Techna Group S.r.l.

In this paper, the effect of various doping and substitution elements on the mechanical fracture of perovskite-type (Pb_0.95Sr _0.05)(Zr_0.52Ti_0.48)O₃-Pb(Mn _1/3Sb_2/3)O₃-Pb(Mn_1/3Nb _2/3)O₃ and (Pb_0.95Sr_0.04)(Zr _1-xTi_x)O₃-Pb(Mg_1/3Nb _2/3)O₃ ceramics was investigated. The predominant transgranular fracture mode was observed in the modified piezoceramics mentioned above and the ZnO, SnO₂ and SiO₂ as trace additives were found beneficial to enhance the mechanical bonding force of grain boundaries. The mechanism of transgranular fracture mode was understood by the diffusion of doping elements into the structural lattice of perovskite-type oxides, agreed with the experimental results of reduced tetragonality, dielectric constant and piezoelectric coefficient. © 2011 Elsevier Ltd and Techna Group S.r.l.

Perovskite-type PbTiO3-PbZrO3-Bi(Zn 0.5Ti0.5)O3 ternary solid solution ceramics were synthesized by conventional solid state reaction method, their structure, dielectric, ferroelectric and piezoelectric properties were investigated. It was found a high piezoelectric and ferroelectric response around the composition of 0.85Pb (Zr0.52 Ti0.48)O3-0.15Bi(Zn 0.5Ti0.5)O3, which was understood by the polarization rotation mechanism in the tetragonal structure. For the Pb 0.85Bi0.15(Zr0.442 Ti0.483Zn 0.075)O3densified ceramics sintered at 1000° C, dielectric constant Ε33T/Ε0 of 1325, piezoelectric constant d33 of 319 pC/N, and permanent polarization Pr of 33.2 μC/cm2 were obtained.

Two kinds of robust modified lead titanate piezoelectric ceramics were prepared with conventional solid state reaction methods, corresponding to two techniques of decreasing tetragonality and thermal expansion coefficient to reduce those crack stresses resulting from ferroelectric phase transition. Their structure, dielectric, ferroelectric and piezoelectric properties were experimentally studied in comparison for the Pb0.88Sm0.08 Ti0.98Mn0.02O3 and Pb0.6Bi 0.4(Ti0.75Zn0.15Fe 0.10)O 3 systems. © Taylor & Francis Group, LLC.