Experimental Study of Acoustic Performance of Porous Metals at High Temperatures

Abstract

Based on an improved two-microphone transfer function method, a testing system for the exploration of acoustic performance of porous materials under high temperature conditions was developed with porous foam copper as one of research objects. The acoustic performances of some porous metallic materials were studied in the temperature range of 300°C to 700°C under the premise of ensuring the temperature stability that makes the measurement uncertainty be ± 6°C at high temperatures. The sound absorption coefficient and the acoustic impedance ratio of porous coppers at different ambient temperatures were acquired accordingly. And then the influence of the variation of temperature fields on the acoustic properties of porous metals was analyzed. The experimental results are in good agreement with the theoretical analysis, which proves the rationality of design of the device and provides important references and specific guidance for future study of the acoustic properties of porous metal materials.