Journal of Advanced Dielectrics, Volume. 14, Issue 1, 2342001(2024)
Preparation and acoustic properties of high-temperature acoustic emission sensor based on La3Ga5SiO crystal
Jingxiang Si, Changhong Yang*, Rui Guo, Yifan Wu, Xiujuan Lin, and Shifeng Huang
Author Affiliations
Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, University of Jinan, Jinan 250022, P. R. Chinashow less
With the rapid development of modern industries, the high-temperature piezoelectric sensors that can work in extreme environments are in great demand. In this work, langasite (La3Ga5SiO, LGS), as a high-temperature piezoelectric crystal with stable electro-elastic performance, is used as core element, and air and porous Al2O3 are selected as backing layers respectively to prepare two kinds of high-temperature acoustic emission (AE) sensors. The detection sensitivities at 25–500∘C are analyzed by the ball falling test and Hsu–Nielsen experiment. Under the condition of 25–500∘C, the received amplitude signals by both sensors are maintained above 90dB stimulated by the ZrO2 ceramic ball dropping. In the Hsu–Nielsen experiment, as the temperature rising from 25∘C to 500∘C, the signal amplitude of sensor with air backing layer decays from 447mV to 365mV, while the signal amplitude varies from 270mV to 203mV for the sensor with porous Al2O3 backing layer. Significantly, compared with the bandwidth of the air-backing sensor (37–183kHz), the sensor with porous Al2O3 backing layer broadens bandwidth to 28–273kHz. These results show that both these AE sensors have strong and stable response ability to AE signals at high-temperature of 500∘C. Therefore, piezoelectric AE sensor based on LGS has great potential application in the field of high-temperature structural health monitoring.