渗流铸造法制备的开孔泡沫铝的声学性能

Sound absorption properties of open-cells aluminum foams prepared by infiltration casting methods

采用反重力渗流铸造法成功制备了开孔泡沫铝材料,对比研究反重力渗流铸造和传统真空渗流法制备的开孔泡沫铝的声学性能。结果表明:两种方法所制备的泡沫铝在高频段的吸声系数均高于低频段的,且在低频段的吸声系数差别不大;在高频段,反重力渗流铸造所得材料的吸声系数明显优于传统真空渗流法所制备材料的,原因是反重力渗流法使泡沫铝中相邻孔洞的连通空间减小;在反重力渗流铸造制备的开孔泡沫铝材料中,造孔粒子粒径与平均吸声系数成反比,孔隙率与平均吸声系数成正比,增大泡沫铝的厚度有利于提高其吸声性能。

The sound absorption properties of the open-celled aluminum foams prepared by the counter-gravity infiltration casting method and traditional process were investigated, respectively. The results show that all the samples prepared by two kinds of infiltration casting methods have the uniform change trend, i.e., the sound absorption coefficient in high-frequency region is higher than that in low-frequency region. The sound absorption property of the sample prepared by the former method is better than that of the sample prepared by the latter method in high-frequency region, which is due to the decrease of connected space between adjacent holes in counter-gravity infiltration casting. The sound absorption coefficient of open-cell aluminum foam prepared by counter-gravity infiltration casting method increases with the particle size decreasing and with the porosity and thickness increasing.