Enhancing Damping of Aluminium Using SiC and∕or Ge

Abstract

Metallic material with enhanced stiffness and damping characteristics is actively sought in the design of dynamic mechanical systems for mechanical components. Germanium is known to remain distinct in an aluminium matrix without forming any intermetallic phases. The effect of the presence of germanium particles in the aluminium matrix is of interest and can be studied in terms of variation in overall damping property, which signifies the internal friction arising at the matrix-particle interface. Damping was measured using an impact-based vibration measurement of a suspended beam coupled with circle-fit approach. Results showed the presence of 1.9 vol. % of Ge in the Al matrix increases the damping capacity by 46% compared to pure Al which is equal to the improvement offered by the presence of 10.2 vol. % of SiC particulates. The present work also extends the study of the additional reinforcement rendered by the presence of SiC particulates along with Ge particulates. The experimental observation of this enhancement in damping characteristics has been rationalized in terms of the microstructural changes such as the presence of plastic zones at the matrix-reinforcement interface.