(哈爾濱工業(yè)大學材料科學與工程學院， 哈爾濱 150001)
摘 要: 采用加壓鑄造工藝成功地制備了多孔鋁合金，孔隙尺寸為0.5～1.6mm，孔隙率為60%～80%，通孔率為85%～100%，最大制品尺寸為d 100 mm×100 mm。掃描電鏡觀察表明，在焙燒期間預制塊顆粒形狀由尖角形變?yōu)閳A形， 顆粒之間的搭接面積變大且過渡平緩；所得多孔金屬孔隙形狀圓滑，互相連通，呈三維網(wǎng)狀結(jié)構(gòu)。對多孔金屬進行的吸聲性能測試表明， 多孔金屬具有較大的吸聲系數(shù)， 不同的多孔鋁合金其吸聲系數(shù)隨頻率的變化趨勢基本相同，當聲波頻率增加時， 多孔鋁合金的吸聲系數(shù)增大。 另外降低多孔鋁合金的孔隙尺寸和增加其孔隙率， 均會使多孔鋁合金的吸聲系數(shù)增大。在實驗測試頻率范圍內(nèi)，當聲波頻率在3.5 kHz時， 多孔鋁合金的吸聲系數(shù)達到最大。
關(guān)鍵字: 多孔鋁合金 結(jié)構(gòu)特征 吸聲系數(shù)
（School of Materials Science and Engineering,Harbin Institute of Technology, Harbin 150001, P. R. China）
Abstract:Porous aluminum alloy was fabricated with pressure casting , whose pore size is 0.5～1.6 mm and porosity is 60%～80%, and the maximum size of the product is d 100 mm×100 mm. SEM observation showed that the preform particles become smooth from sharp angle after baking in a furnace, and the interlace area between two particles is larger and changes smoothly. The porous aluminum alloy was obtained with smooth pores and connecting with each other and being three-dimensional net-shape distribution. The sound absorbing property measured in the experiment showed that the porous aluminum alloy has large sound absorbing coefficient . For different porous aluminum alloys the change of sound absorbing coefficient with sound frequency is basically same. When the sound frequency increases, the sound absorbing coefficient of porous aluminum alloys increases. In addition the porosity of porous aluminum increasing or pore size decreasing, the sound absorbing coefficient also increases. When the sound frequency is 3.5 kHz, the sound absorbing coefficient becomes the maximum, which is different with different pore size and porosity.
Key words: porous aluminum alloy microstructure feature sound absorbing coefficient
