(哈尔滨工业大学材料科学与工程学院， 哈尔滨 150001)
摘 要: 采用加压铸造工艺成功地制备了多孔铝合金，孔隙尺寸为0.5～1.6mm，孔隙率为60%～80%，通孔率为85%～100%，最大制品尺寸为d 100 mm×100 mm。扫描电镜观察表明，在焙烧期间预制块颗粒形状由尖角形变为圆形， 颗粒之间的搭接面积变大且过渡平缓；所得多孔金属孔隙形状圆滑，互相连通，呈三维网状结构。对多孔金属进行的吸声性能测试表明， 多孔金属具有较大的吸声系数， 不同的多孔铝合金其吸声系数随频率的变化趋势基本相同，当声波频率增加时， 多孔铝合金的吸声系数增大。 另外降低多孔铝合金的孔隙尺寸和增加其孔隙率， 均会使多孔铝合金的吸声系数增大。在实验测试频率范围内，当声波频率在3.5 kHz时， 多孔铝合金的吸声系数达到最大。
关键字: 多孔铝合金 结构特征 吸声系数
（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
