Design, fabrication and sound absorption performance investigation of porous copper fiber sintered sheets with rough surface

A novel porous copper fiber sintered sheets (PCFSSs) with different porosities were fabricated using the cutting copper fibers with rough surface. The effect of fiber surface morphology, porosity, thickness and gradient pore structure of PCFSS on sound absorption performance was tested by using the transfer function method. Our results show that the copper fiber sintered sheets with rough surface exhibited better sound absorption performance compared with the copper fiber sintered sheets with smooth surface. The increase of sound resistance by increasing thickness or decreasing porosity could significantly improve the sound absorption coefficients in the low frequency region and widen its acoustic absorption bandwidth. Whereas, the sound absorption performance in the high frequency region was decreased with the increase of sound resistance. Moreover, the three-layer PCFSSs with gradient pore structure could cause a repeated propagation and dissipation due to the reflection of sound waves between the gradient interfaces, which can satisfy the requirements of noise control in different frequency region. Our work provides a method for improving sound absorption performance of porous metal material for different applications. (C) 2020 Elsevier Ltd. All rights reserved.