烧结FeCrAl纤维多孔材料的吸声特性

Sound Absorption Characteristics of FeCrAl Sintering Fibrous Porous Materials

采用Φ20μmFeCrAl纤维制备纤维多孔材料,孔隙度大于85%。在常声压与高声压条件下分别对烧结FeCrAl纤维多孔材料进行吸声性能检测。结果表明,在常声压下,材料的吸声特性随孔隙度的增加而提高,但是对于高频的吸收,孔隙度过高或过低都不利于吸收。厚度越大,材料的吸声性能越好。增加空腔可以提高材料在低频的吸声性能;在高声压条件下(100～140dB),该材料的吸声特性不随声压级的变化而变化,各参数对吸声性能的影响规律与在常声压条件下的规律一致。频率在2.5～6.4kHz之间,声压级为120dB条件下,孔隙度为94%、20mm厚的FeCrAl纤维多孔材料吸声系数达到90%。

FeCrAl fibrous porous materials with the porosity larger than 85% were prepared using the fiber of 20 μm in diameter as starting material. Under the ordinary sound pressure and high sound intensity conditions, the sound absorption properties of FeCrAI sintering fibrous porous materials were tested. The results indicate that the sound absorption properties of FeCrAl fibrous porous materials were increased by increasing of the porosity under ordinary sound pressure. But it was not beneficial to sound absorption under high frequency when the porosity was too high or too low. The larger the thickness was, the better the sound absorption properties of FeCrAl fibrous porous materials were. Adding the airspace can improve the sound absorption properties under low frequency. Under high sound intensity （100-140 dB）, the sound absorption properties of the material would not change with the sound pressure level （SPL）; effects of the parameters on the sound absorption properties were in concordance with that under ordinary sound pressure. The sound absorption coefficient of FeCrAl fibrous porous materials with 94% porosity and 20 mm thickness was up to 90% at 120 dB and in the frequency range of 2.5-6.4 kHz