2013 article

High-temperature (> 1000 degrees C) acoustic emission sensor

NONDESTRUCTIVE CHARACTERIZATION FOR COMPOSITE MATERIALS, AEROSPACE ENGINEERING, CIVIL INFRASTRUCTURE, AND HOMELAND SECURITY 2013, Vol. 8694.

By: J. Johnson n, K. Kim n, S. Zhang *, D. Wu n & X. Jiang n

co-author countries: China πŸ‡¨πŸ‡³ United States of America πŸ‡ΊπŸ‡Έ
author keywords: Acoustic emission; sensor; high temperature; YCOB; hsu-nielsen
Source: Web Of Science
Added: August 6, 2018

Piezoelectric crystals have shown promising results as acoustic emission sensors, but are often hindered by the loss of electric properties above temperatures in the 500-700°C range. Yttrium calcium oxyborate, (YCOB), however, is a promising high temperature piezoelectric material due to its high resistivity at high temperatures and its relatively stable electromechanical and piezoelectric properties across a broad temperature range. In this paper, a piezoelectric acoustic emission sensor was designed, fabricated, and tested for use in high temperature applications using a YCOB single crystal. An acoustic wave was generated by a Hsu-Nielsen source on a stainless steel bar, which then propagated through the substrate into a furnace where the YCOB acoustic emission sensor is located. Charge output of the YCOB sensor was collected using a lock-in charge amplifier. The sensitivity of the YCOB sensor was found to have small to no degradation with increasing temperature up to 1000 °C. This oxyborate crystal showed the ability to detect zero order symmetric and antisymmetric modes, as well as distinguishable first order antisymmetric modes at elevated temperatures up to 1000 °C.