Mechanical and Damping Properties of Silicon Bronze Alloys for Music Applications

An alloy for musical instruments should have high enough strength, hardness, specific elastic properties and low damping capacity. The high tin bronze alloys with composition 20-22 wt.% Sn has good acoustical properties, which is capable of producing long-lasting slowly damping vibrations but there is brittle materials. Cracks and fracture may appear on these materials. The study on mechanical and acoustic characteristic becomes the primary consideration in determining the new material as a musical instrument. The aim of this study is to investigate the effect of silicon fraction of Cu-(2.5-7.5) wt. % Si on mechanical and acoustical properties of bronze alloys for music instruments. Ascast Cu-(2.5-7.5) wt. % Si were cut from 250 x 55 x 15 mm of billet and manufactured for tensile, hardness, impact, and damping test specimen. Simply supported beam model was used for measuring damping capacity. Mechanical and damping properties of silicon bronze (Cu-Si) were studied. Investigation of bronze 20 wt. % Sn alloys was conducted as comparison. The results show that the mechanical properties and damping capacity of Cu-xSi is higher than Cu-20 wt. % Sn bronze alloys. The ductility and impact strength of silicon bronze also higher than this of tin Cu-20 wt.% Sn. It is recommended that Cu (5-7.5) wt. % Si are suitable to substitute tin bronze (Cu-20 wt.% Sn) for music instrument applications. Keyword, Tin bronze, silicon bronze, mechanical properties and damping capacity