Internal friction of porous copper with hydrogen pores

摘要

Porous copper whose long cylindrical pores were aligned in one direction was fabricated by unidirectional solidification of the melt in a pressurized mixture gas of hydrogen and argon. The internal friction of the porous copper was measured by a forced vibration method with the frequency range from 0.1 to 2Hz up to 1100K. A very large internal friction peak was observed at about 700K for the porous copper with closed pores, while no peak was found for non-porous copper and porous copper with the open pores. This peak strength depends on the porosity, the annealing time and measurement frequency. Such large internal friction peak may be attributed to hydrogen in the porous copper.