Lead-Free AE Sensor Based on BZT-BCT Ceramics

Traditional AE sensors often rely on lead-based ceramics, which raise environmental concerns. Recent research has shifted toward lead-free alternatives to address these issues. Prior studies have shown that barium titanate-based ceramics can exhibit strong piezoelectric properties. However, the impact of ceramic shape on AE sensor performance remains underexplored. This gap motivated the investigation of BZT-BCT ceramics. The study aimed to determine if shape optimization could enhance sensor output. No prior work had resolved the relationship between D/T ratios and sensor sensitivity. The need for environmentally friendly, high-performance AE sensors persists. This paper contributes to the field by exploring a novel lead-free ceramic composition.

The goal was to develop a lead-free AE sensor using BZT-BCT ceramics. The specific problem addressed was the lack of high-performance, environmentally friendly AE sensors. The motivation stemmed from the environmental drawbacks of lead-based materials. The study tested whether ceramic shape influences sensor performance. Researchers aimed to identify optimal D/T ratios for sensitivity and frequency. The design focused on varying ceramic dimensions systematically. The approach involved fabricating ceramics with different D/T ratios. The study sought to determine the best configuration for AE sensor applications.

The study used BZT-BCT ceramics with varying D/T ratios. Ceramics were fabricated with D/T values of 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0. Each shape was tested for acoustic and electromechanical properties. The piezoelectric charge coefficient was measured for each sample. Voltage and coupling factors were also assessed. Resonant and anti-resonant frequencies were recorded. The ceramic with D/T = 1.0 was selected for detailed analysis. Performance metrics included sensitivity and frequency response.

The BZT-BCT ceramic with D/T = 1.0 showed the highest piezoelectric charge coefficient of 370 pC/N. The voltage coefficient reached 11.3 × 10⁻³ Vm/N. The electromechanical coupling factor was 0.58. Resonant frequency was 172.724 kHz. Anti-resonant frequency was 196.067 kHz. The effective coupling factor was 0.473. Sensitivity reached 65 dB. Frequency response was 30 kHz.

The authors propose that the D/T ratio significantly affects AE sensor performance. The BZT-BCT ceramic with D/T = 1.0 demonstrated optimal properties. The study suggests that shape optimization enhances sensor sensitivity and frequency. The findings may guide future sensor design using lead-free ceramics. The researchers note that the selected ceramic configuration maximized output. The study does not claim that other materials cannot achieve similar results. The results may inform the development of eco-friendly AE sensors. The authors suggest that this approach could be applied to other ceramic compositions.