Fabrication of porous copper by unidirectional solidification under hydrogen and its properties

Lotus-structured porous copper was fabricated by unidirectional solidification in the mixture gas of hydrogen and argon at the high pressure up to 2 MPa. The pore size and porosity were controlled by the melting temperature and the mixture ratio and pressure of the gases, while the pore growth direction was controlled by the freezing direction. The pore diameter ranges from 5 μm to 5 mm and maximum porosity is about 70%. The porous copper with aligned long pores displays superior mechanical properties, which is different from conventional porous materials with random pores such as sintered materials, foamed materials, cell-structured materials etc. In this paper the fabrication and the result of the mechanical property and the internal friction measurement are described.