PZT Piezoelectric Ceramics: A Versatile Material for Quality Monitoring and Structural Integrity Assessment

Abstract

A PZT-based acoustic emission (AE) sensor was used to record signals during manual arc welding on a mild steel plate. Out of 140 recorded hits, 13 signals from regions of acceptable weld profile were analysed in both time and frequency domains, and the RMS amplitude, peak amplitude, and signal energy were compared between good and defective weld locations. In this limited dataset, all three parameters were consistently higher for poor-quality welds than for the good weld, and this trend was corroborated by metallographic inspection, which confirmed cracks, porosity, and lack of sidewall fusion at the locations of the highest-amplitude signals. Frequency-domain analysis further enhanced the distinction, with defective welds exhibiting peak amplitudes up to 94 dB compared to 60 dB for sound welds. Because the dataset is small and only 13 of 140 recorded hits were analysed, these results should be regarded as an indicative pilot observation rather than a statistically validated finding; they nonetheless illustrate the potential of PZT-based AE sensors for real-time weld-quality monitoring and motivate a larger follow-up study.