Sound absorbing structure

摘要

The structure to absorb sound is composed of hollow structure units within an outer shell with free loose particles or a free hollow body. The particles or bodies can be fee or bonded together by an adhesive, solder or sintering within a matrix. The hollow structures have outer dimensions of 0.5-30 mm within a shell thickness of 10-3000 mu m with a shell of metal or a metal alloy, or a ceramic. The particles can be of carbide, nitride, oxide, silicide, with a preferred oxide of Al2O3, ZrO2, Y2O3, MgO or Fe2O3, Fe3O4, CoO, NiO, MoO3 and CuO.