Abstract
The improvement of sound absorption performance of porous metal is a focus of research in the field of noise reduction. Influences of compression ratios on sound absorption performance of a porous nickel-iron (Ni-Fe) alloy were investigated. The samples were compressed with ratios from 10% to 80% at an interval of 10%. Based on the standing wave method, sound absorption coefficients of compressed samples with different thicknesses were obtained. It could be found that with the same compression ratio, sound absorption performance was improved with the increase of thickness. Based on the modified Johnson-Allard model with a correction factor, the sound absorption coefficient of the porous Ni-Fe with a thickness of 20 mm for different compression ratios was derived, whose aim was to quantificationally analyze influences of the compression ratio. The results indicated that the sample with a compression ratio of 70% exhibited optimal sound absorption performance, and its average sound absorption coefficient reached 88.97% in a frequency range of 1000–6000 Hz. Meanwhile, the section morphologies of compressed samples were investigated by a scanning electron microscope, which studied the sound absorption performance by analyzing structures of the porous Ni-Fe samples with different compression ratios. The obtained achievements will promote the application of the porous Ni-Fe alloy in the field of acoustics.
Highlights
Applications of porous metal in pollution control of urban noise make it a focus of research in the field of acoustics, because noise pollution greatly damages physical and mental health of humans and it can generate some diseases [1,2]
It could be found that for a constant compression ratio, the sound absorption coefficient was improved along with increasing the thickness of the sample, which was consistent with the normal sound absorption performance of the common porous metal [10,22,23]
Quantitative analysis of the influence of the compression ratio on sound absorption performance was conducted by comparing sound absorption coefficients of the compressed samples with the same thickness of 20 mm, which was the limit of the sound absorber for certain engine equipment
Summary
Applications of porous metal in pollution control of urban noise make it a focus of research in the field of acoustics, because noise pollution greatly damages physical and mental health of humans and it can generate some diseases [1,2]. Compression can improve the sound absorption performance of porous metals with a limited dimension in general, the sample cannot be infinitely compressed and the sound absorption coefficient cannot be improved in full spectrum. The sound absorption coefficient of the porous Ni-Fe alloy with a compression ratio ratio 0%. Afterwards, section morphologies section morphologies of the were compressed were studied with scanning (SEM), electronwhich microscopy of the compressed samples studiedsamples with scanning electron microscopy could (SEM), which could qualitatively explain influences of the compression ratio on the sound absorption qualitatively explain influences of the compression ratio on the sound absorption performance of the performance the porous Ni–Fe alloy
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
