Damping properties and mechanism of aluminum matrix composites reinforced with glass cenospheres

The damping properties were improved by preparing Al matrix composites reinforced with glass cenospheres through the pressure infiltration method. Transmission electron microscopy and scanning electron microscopy were employed to characterize the microstructure of the composites. The low-frequency damping properties were examined by using a dynamic mechanical thermal analyzer, aiming at exploring the changing trend of damping capacity with strain, temperature, and frequency. The findings demonstrated that the damping value rose as temperature and strain increased, with a maximum value of 0.15. Additionally, the damping value decreased when the frequency increased. Dislocation damping under strain and interfacial damping under temperature served as the two primary damping mechanisms. The increase in the density of dislocation strong pinning points following heat treatment reduced the damping value, which was attributed to the heat treatment enhancement of the interfacial bonding force of the composites.