Equal-channel angular extrusion process of lotus-type porous copper

Deformation behavior of lotus-type porous copper with long cylindrical pores aligned in one direction through equal-channel angular extrusion (ECAE) process was investigated using dies with channel angles 90° and 150°. The lotus-copper rod was densified by the uni-axial compression in the entry channel, and the pores were thinned and elongated by shearing at the corner of the 90°-die. The inclination angle of the elongated thinned pores can be explained by a geometric deformation model considering the densification. After the second path of the ECAE the pores were either further thinned and elongated or opened again according to the pass route. Extrusion through the 150°-die changed the pore morphologies little. The Vickers hardness increased through the ECAE process. From these results we found that it may be possible to improve the mechanical properties of porous metals and to control the pore morphology by means of the ECAE process.