新型船用吸声材料泡沫铝

Research on New Marine Sound-absorbing Material Foamed Aluminum

扼要介绍了用熔体发泡法制造泡沫铝的制造过程 ,泡沫铝孔径为 2～ 7mm,孔隙率为 80 %～ 90 % ,最大制品尺寸为 60 0 m× 60 0 mm× (8～ 40 0 ) mm。重点研究了泡沫铝的吸声性能、热学性能、阻尼性能、机械性能、吸湿性能及无毒性能。结果表明 ,泡沫铝是一种综合性能良好的新型吸声材料。平均吸声系数可达 0 .4～ 0 .5 2 ,且随孔径的减小 ,孔隙率、厚度的增大 ,吸声性能提高。压缩加工对泡沫铝的吸声性能有很大影响 ,压缩率为 40 %时 ,吸声性能最好。泡沫铝导热系数仅为未发泡铝的 1 /60 0 ,远远低于大理石 ,也低于石棉板 ;耐火温度可达 80 0℃。其内耗比致密铝高 3～ 7倍 ,比高阻尼 Zn-Al合金高 2～ 4倍。其强度为几个 MPa数量级。它不吸湿 ,吸湿率为 0 .0 % ,无毒性。

In this paper, the fabrication of foamed aluminum by melt foaming technique is briefly introduced. The pore diameter of foamed aluminum is 2～7mm, porosity is 80%～90% and the maximum size of the product is 600mm×600mm×(8～400)mm. The sound absorbing property, thermal, damping property, mechanical property, moisture absorbing property and nonpoisonous property are studied. The results show that foamed aluminum is a new type of sound absorbing material which has good synthetic properties. Its average sound absorbing coefficient reaches 0.4～ 0.52. When its pore diameter decreases, or its porosity and thickness increase, the sound absorbing property may be improved. The influence of compressive process on sound absorbing property of foamed aluminum is evident. When the compressive ratio is 40%, the sound absorbing property will be the best. Its thermal conductivity coefficient is only 1/600 times as large as that of normial aluminum. The thermal conductivity coefficient is not only far lower than that of marble but also lower than that of asbestos board. Its fire resistant temperature is 800℃. Its internal friction is 3～7 times higher than that of the massive aluminum and 2～4 times than Zn Al high damping alloys internal friction. The strength of foamed aluminum is several MPa. Foamed aluminum does no tabsorb moisture, its moisture absorbing ratio is 0.0%, and it is nonpoisonous.