High-Temperature Sintering: The Key to Performance Upgrading of Piezoelectric Ceramic Sheets

In the preparation process of piezoelectric ceramic sheets, high-temperature sintering is the core link that determines the upper limit of their performance. By precisely controlling the sintering temperature and atmosphere, this high-temperature process not only solves the performance bottlenecks of traditional processes but also meets the stringent requirements of high-end fields such as new energy and aerospace, becoming a key support for the upgrading of the piezoelectric ceramic industry.

The most significant advantage of high-temperature sintering is to improve material density and piezoelectric properties. PZT ceramics sintered at medium and low temperatures in traditional processes often have high porosity and numerous grain boundary defects, leading to insufficient piezoelectric constants. In contrast, high-temperature environments promote uniform grain growth and dense particle fusion. PZT ceramics treated at temperatures above 1200°C can achieve a density of over 96%, with an 8% increase in piezoelectric constant d33 compared to traditional processes, and dielectric loss controlled below 1.2%. The Sm-PMN-PT ceramic developed by the Xi'an Jiaotong University team, after high-temperature sintering at 1235°C, has a piezoelectric coefficient as high as 1285 pC/N, setting a new record for high-performance piezoelectric materials.

Adapting to the lead-free trend and special materials is another core value of high-temperature sintering. With the upgrade of the EU RoHS directive, lead-free piezoelectric ceramics have become mainstream, and lead-free systems such as KNN-based and BiAlO₃-based require higher sintering process requirements. High-temperature sintering combined with atmosphere control technology can effectively inhibit the volatilization of components such as Bi₂O₃, keeping the Curie temperature of lead-free ceramics stable above 500°C to meet high-temperature working conditions. For PZT systems, high-temperature sintering combined with nano additives can reduce lead volatilization by 65%, balancing environmental protection and performance.

High-temperature sintering also endows piezoelectric ceramic sheets with excellent stability in extreme environments. In scenarios such as aviation engine sensors and oil exploration equipment, devices need to withstand complex conditions such as high temperature and vibration. Ceramic sheets sintered at high temperatures have a mechanical strength improvement of more than 15%, show no cracking after 1000 thermal cycles, and have a piezoelectric performance attenuation rate of less than 5% at 200°C, far exceeding medium and low-temperature products. This stability enables them to work reliably for a long time in intelligent vehicle ADAS radar and ultrasonic medical equipment.

From the laboratory to mass production lines, high-temperature sintering, by optimizing microstructure and adapting to new materials, has opened up high-end application space for piezoelectric ceramic sheets, becoming a key force driving their upgrade from 'basic components' to 'core devices'.