High piezoelectric and dielectric properties of 0–3 PZT/cement composites by temperature treatment

Temperature treatment of 0–3 type PZT/cement composites before polarization yielded high dielectric and piezoelectric properties in materials with 50% PZT inclusions by volume and 50% cement matrix. Specimens were treated at seven temperatures from 23 °C to 150 °C and then applied by a 1.5 kV/mm poling field. The dielectric loss of the composites reduces at higher pretreatment temperatures, shorting the trigger time. Temperature treatment increased the piezoelectric strain factor d33, the relative dielectric constant εr and the piezoelectric voltage factor g33 of PZT/cement composites, but did not affect significantly the electromechanical coupling coefficient Kt. Piezoelectric factors reach stable values after 70 days of aging, and samples that were not temperature pretreated reached stable values earlier. Specimens pretreated at 150 °C exhibit d33 = 106.3 pC/N and εr = 477 on the 70th aging day, almost two times greater than the composites without temperature treatment. The resonance frequency of the composites on the 70th day decreases with increasing temperature, with the exception of 150 °C. Temperature pretreatment can also improve the phase angle of the composites. In addition, the effect of curing time for PZT/cement composites is an important factor to dominate the feasibility of polarization.