Sound Absorption Performance Study Of The Combination Of Through-hole Aluminum Foam Structure

Aluminum foam as the structure and function in one of the porous metal materials causeattention by the academia and research institutions become the research hotspot. Aluminumfoamed interior network structure and communicated with the surface structure characteristicsare conducive to the sound absorption. As a functional material, sound absorption is one ofthe major characteristics, but as the sound-absorbing material, it has high absorptionperformance is good, and low frequency sound absorption performance, the characteristics ofpoor, therefore how to use technical means to improve the through hole foam materials of low,intermediate frequency sound absorption performance, will facilitate the open-cell aluminumfoam as the sound absorption material application and promotion.In this paper, using thestanding wave tube method of5kinds of apertures, each aperture3thickness through holesound absorption characteristics of aluminum foam, and aluminum foil, sound-absorbing film,sound absorption of different thickness of ultra-fine glass wool, back cavity composite isformed after the post with a composite sound absorption performance, the main experimentalband100Hz~2000Hz, experimental studies suggest:1. open-cell aluminum foam under the condition of post back cavity through hole soundabsorption characteristics of foamed aluminum was substantially increased, the scheme ofsmall aperture (aperture <1mm) sound absorption compared with large aperture through-holefoamed aluminum (size>1mm);2. open-cell aluminum foam with aluminum foil, absorbing film are respectivelycombined back cavity can improve the low frequency sound absorption performance, but thealuminum foil and the sound absorption film for intermediate frequency sound absorptionperformance have a weakening effect;3. the foam aluminum and glass cotton combinations, two kinds of materials in soundabsorption are complementary, with glass cotton thickness increases, sound absorptionperformance gradually increased, and in certain frequency range, the sound absorptionproperties of composite structure of more than two kinds of materials in the frequency rangeof sound absorption coefficient and at the same time of aluminum foam and glass fibercomposite add back cavity of aluminum foam, different average absorption coefficient increases, low frequency, excellent sound absorption performance;4. through hole aluminum foam paste aluminum foil composite superfine glass wool andback cavity, the combination may cause the low-frequency sound absorption performance isfurther improved, at the same time the glass cotton good intermediate frequency soundabsorption performance and stability of the absorption peak of mid-frequency soundabsorption properties, although the average absorption coefficient than the open-cellaluminum foam with superfine glass set back cavity combined declined, but can still maintaingood sound absorption properties of open-cell aluminum foam; sound absorption membranecomposite superfine glass wool and back cavity, sound absorption effect is not good, soundabsorption film is not conducive to the combination mode, sound absorption film forintermediate frequency sound absorption performance in suppressing the severe;5. small aperture (aperture <1mm) aluminum foam combination is more beneficial tothe low frequency sound absorption performance, large aperture (aperture of>1mm) is moreadvantageous to the intermediate frequency sound absorption performance.