Analysis of damping spectra of silver-plated brass from a Weltklang saxophone manufactured in 1969

摘要

The damping of wall vibrations in material of musical instruments influences its sound, but the damping capacity of the materials is rarely investigated. One of the most used material for musical wind instruments is alpha-brass. Therefore, samples from a saxophone manufactured of silver plated Cu28%Zn with small Pb content were investigated by scanning electron microscopy, energy dispersive spectroscopy, X-ray fluorescence, thermogravimetric analyses coupled with Fourier transform infrared spectroscopy, and mechanical spectroscopy. Pb particles are located at grain boundaries. Damping spectra show three relaxation peaks which can be attributed to Zener and/or solvent grain boundary relaxation, a peak due to dislocation defect interactions and a solute grain boundary peak. The peak temperatures of these peaks are higher in silver plated brass than for brass without silver cover due to AgCO3 particles. The silver plating process led to the formation of Zn and Cu carbonates. Thermal decomposition of these carbonates to ZnO and CuO together with lead particles leads to blocking of the solute grain boundary peak.