Influence of Macroscopic Graphite Particulates on Damping Properties of Commercially Pure Aluminum

Macroscopic graphite particulate reinforced commercially pure aluminum metal matrix composites (MMCs) were prepared by pressure infiltration process.The damping characterization was conducted using a multifunction internal friction apparatus (MFIFA).The internal friction (IF) and relative dynamic modulus were measured at frequencies of 0.5,1.0 and 3.0 Hz in the temperature range of 25 to 400 ℃.The microstructure analysis was performed using TEM.Influence of macroscopic graphite particalates on damping properties was studied by the measurement of IF and microstructure analysis.The damping capacity of the composites was increased 2-3 folds with the increase of macroscopic graphite particulates volume fraction.The operative damping mechanisms in the macroscopic graphite particulate reinforced MMCs were discussed in light of internal friction measurements and microstructural studies.