金属纤维多孔材料的吸声性能

Sound Absorption Properties of Fibrous Porous Metals

采用松装、压制、定位3种烧结方式制备了厚度为1~30 mm的不锈钢纤维多孔材料,采用丹麦B&K公司的双传声器阻抗管测试吸声系数,系统研究了孔隙度和丝径对吸声性能的影响规律。结果表明:在不同厚度条件下,孔隙度有着不同的最佳范围值,如1~3 mm时,孔隙度在80%~85%的范围内,5 mm时,孔隙度在85%~90%的范围内,10~15 mm时,孔隙度在90%~94%范围内全频吸声性能较好,随着厚度的增加,这个最佳范围值随之增大;在厚度≤mm时,材料的丝径越细,全频吸声性能越好;当厚度在3~20 mm的范围内时,随着厚度的增加,粗丝径样品的吸声性能逐渐变好,其吸声峰值向低频移动,并且保持着高频处较好的吸声性能;当厚度220 mm时,材料的丝径越粗,全频吸声性能越好。

Fibrous porous metals with thickness from 1 mm to 30 mm were prepared by three kinds of sintering processing,loose sintering,compacting sintering,and positioning sintering.The absorption coefficient was tested by a double microphone impedance measurement tube of BK Company in Denmark.The effects of the porosity and the wire diameter on the sound absorption properties were studied.The results show that there are different optimum ranges of porosity with different thicknesses.When the thickness is from 1 mm to 3 mm,the optimum porosity range is from 80%to 85%;when the thickness is 5 mm,the optimum porosity range is from 85%to 90%;with the thickness from 10 mm to 15 mm,the optimum porosity range is 90%～94%,and with the increases of thickness,the porosity increases in the optimum range.When the thickness 3 mm,the smaller the fiber diameter is,the better the sound absorption performance is in the whole frequency.When the thickness is from 3 mm to 20 mm,with the thickness increasing,the sound absorption performance of the materials with smaller wire diameter become better gradually,the absorption peak shifts to the low frequency,and the sound absorption performance still keeps very well at high frequency.When the thickness≥ 20 mm,the larger the fiber diameter is,the better the sound absorption performance is in the whole frequency.