Enhanced viscoelastic properties of nickel–aluminum–bronze alloyed with indium or its alloys

Abstract

Engineering structures may be sensitive to vibrations such that their normal functioning is impaired due to the presence of vibrations. A material capable of dissipating energy of vibration by means of heat tends to have better mechanical damping properties. However, due to the demands on structural stability, the material needs to have sufficient stiffness to be useful structurally. Thus, the material must have both high stiffness and high mechanical damping. This paper discusses a variety of materials that were uniquely developed to achieve the aforementioned objectives. The new nickel–aluminum–bronze (UNS C95800)-based samples were classified according to alloying composition by weight percentage with different indium alloys. A dynamic mechanical analyzer was used to find the complex modulus (|E*|) and loss tangent (tan δ) values of the samples. These values were used to evaluate and compare the figure-of-merit (FOM) across different frequencies at a particular temperature and strain. The samples which have FOM equal to or greater than 0.6 GPA include the ones alloyed with pure indium (5 wt%), eutectic solder (5 wt%), indium–bismuth eutectic (10 wt%), bismuth–tin eutectic (5 and 10 wt%), and indium–tin eutectic (5 wt%). The newly alloyed high-damping metals can be used to reduce vibration while maintaining their stiffness.