Acoustic studies on porous sintered powder metals

In response to strict environmental noise regulations the development of novel types of silencing materials is essential. The composition of the porous sintered powder metals (PSPMs) studied in this paper is based on the formation of sintered powder particles providing internal micro-paths (tunnels and pores) and cavities. In the micro-path the energy dissipation of the acoustic waves is primarily originated by thermal and viscous losses. The transfer impedance and absorption as the key parameters are presented and analysed for the PSPM samples designed. In order to study the influence of loudness on the acoustic performance the test samples are exposed to a variety of sound excitation levels during the experiments.