Fabrication of Porous Aluminium and Copper Media by Using Monotectic Solidification under a Magnetic Field
Unidirectional solidification of Al-In, Cu-Pb and Cu-Pb-Al monotectic alloys was performed under static magnetic fields up to 10T for formation of the regularly aligned-rod structure. mThe imposition of static magnetic fields exceeding 4T suppressed movement of the In liquid droplets at the Al solidifying front and enhanced the engulfment of the In droplets into the front. As a result, the eutectic-like structure was obtained in the Al-10 and 15at%In hypermonotectic alloys. The micro X-ray tomography indicated that the continuous In rods with diameters of 10-20 µm were aligned parallel to each other. In the case of the Cu-Pb and the Cu-Pb-Al alloys, the imposition of static magnetic fields also enhanced the formation of the aligned Pb rods. The electrochemical etching by using a 10% HNO3 solution successfully removed the minor phase, and the porous aluminum and copper with deep pores were fabricated.
Yukichi Umakoshi and Shinji Fujimoto
H. Yasuda et al., "Fabrication of Porous Aluminium and Copper Media by Using Monotectic Solidification under a Magnetic Field ", Materials Science Forum, Vol. 512, pp. 289-294, 2006