Acoustical Performance Of Composite Structure With Stainless Steel Fibrous Porous Materials

Environmental noise had a great influence on the precision of electronic components, therefore complicated hardware and software were necessary to processing the signal, which increased the weight and cost, and decreased the reliability of the system. Acoustic enclosure was the most effective process to reduce the influence of environment noise. But, very little space could be used in electronic components, it required thin sound insulation materials to control the noise, especially for low frequency noise. Therefore, using the composite structure with sound absorbing materials and lamina plate was an effective way to improve the precision of electronic components. Sintered stainless steel fibrous materials are novel combining structure developed with new manufacturing technologies and materials processing. It is becoming focus of study in sound absorbing material fields since its excellent sound absorbing performance, but had few relevant reports about sintered stainless steel fibrous materials used in sound insulation of precision electronic componentsThis paper aimed at the application of thin porous-plate combining materials for sound insulation of electronic components. Porous materials were prepared from316L stainless steel fibers by sintering process. Sound absorbing structure was composed from perforated plate and porous materials. The sound absorption performance of the fiber porous materials was tested, and the influences of pore structure and the composite patterns were investigated to optimal the performance of acoustic enclosure. Attempted achieve the requirement of electronic components to noise through enhancing sound absorbing coefficient.The results indicated that mean pore sizes, fiber diameter and thickness of samples played an important role for sound absorption. The designed gradient structure of mean pore sizes and fiber diameter showed higher sound absorption coefficient. The average sound absorption coefficient for the frequency3000Hz is above0.5. Sound absorption composite structure with perform plate and porous materials had obviously improved sound absorbing performance of stainless steel fibrous porous materials under frequency of3000Hz. And the maximum sound absorbing coefficient of the gradient stainless steel fiber porous materials is0.8. Gradient structures with three layers or sound absorbing structure composited to lamina plate approximately enhanced lOdB higher than that of lamina plate. The acoustic insulation reduced almost half of the noisy level of out put signal of the electronic components.The research is funded by National "973" Project (NO.2011CB610302) and Shan’xi new scientific star Project (NO.2012KJXX-47) and finished in State Key Laboratory of Porous Metal Materials...