Fabrication and Damping Properties of Porous Cu

The porous Cu specimens were prepared using infiltration process. Its damping behavior was investigated using multifunction internal friction apparatus over the temperature range from 40°C to 500°C.The size of macroscopic pore is in the order of a millimeter (1.0mm) and in large proportions, typically up to 60vol%. The measured IF (internal friction) shows that the damping capacity of porous Cu is higher than that of its bulk metal. It’s found that two IF peaks present at the internal friction against temperature curves at around 280°C and 400°C.The high-temperature arises from the relaxation of grain boundaries. The low-temperature peak may origin from the interaction of dislocation and grain boundaries. TEM observations showed the dislocation substructures exist in the porous Cu. Based on the observed experimental phenomena, a four-parameter mechanical model was used for describing the operative damping mechanism of the low-temperature peak in the porous Cu specimen.