Investigation on acoustic properties of metal hollow sphere A356 aluminum matrix composites

Abstract

The acoustic performance of metal hollow sphere (MHS) A356 aluminum matrix composites has a significant impact on their application, making it worthy of in-depth investigation. To investigate the acoustic performance and mechanism of MHS A356 aluminum matrix composites, in this study MHS A356 aluminum matrix composites with different structural parameters were fabricated using a casting method. The density of the MHS A356 aluminum matrix composites was measured using the direct measurement method, and the acoustic performance of the composites was measured using the impedance tube. The research results indicated that the average sound absorption coefficient of MHS A356 aluminum matrix composites increased with the decrease in sintering temperature and diameter of MHSs, and the increase in volume fraction of MHSs. When the sintering temperature of the MHS was at 1,100°C, with the volume fraction being 48.50% and the diameter being 1.88 mm, the average sound absorption coefficient of the MHS A356 aluminum matrix composites reached the optimal level, which was 0.23. Conversely, the sound transmission loss of MHS A356 aluminum matrix composites decreased with the increase in sintering temperature, volume fraction, and diameter of MHSs. When the sintering temperature of the MHS stood at 1,100°C, with the volume fraction being 40% and the diameter being 2.88 mm, the average sound transmission loss of the MHS A356 aluminum matrix composites attained the maximum value, which was 24.6 dB.

Keywords

• metal hollow spheres composites
• sound absorption coefficient
• sound transmission loss
• sound absorption and insulation mechanism
• structural parameters