Abstract:

Three kinds of graphite particulate reinforced zinc based MMCS with 5, 10 and 15 volume fraction percent were prepared by spray co deposition. Five percent of silicon was added to alloy ZA27 in order to get a fine matrix. The internal friction apparatus was used to evaluate the low frequency internal friction behavior of the materials investigated. Experimental results showed that the damping capacity of MMCS was related to the temperature. At the temperature below 40℃, the damping capacities of MMCS were lower than that of the as spray deposited material. While their properties were higher than it with the temperature increasing. Then the concept of thermal activation was adopted to explain the experimental results that the temperature at which the low frequency internal friction has no frequency dependency, linearly increases with the graphite volume fraction. Finally, the operative damping mechanisms were discussed in the light of the data obtained from characterization of microstructure and damping capacity.

Key words: spray co- deposit ion, zinc- based alloy, composites, low fr equency inter nal fr iction