Melt extraction of gold fibers and precious metal doped fibers and preparation of porous gold fiber structures

Crucible melt extraction yields short metal fibers with eqivalent diameters as low as 50 µm from almost arbitrary metals and alloys. Highly porous components can be made from such fibers by suitable deposition and sintering methods. This technology is being developed at the Dresden based Department of Powder Metallurgy and Composite Materials of the Fraunhofer Institute for Manufacturing and Advanced Materials (IFAM) and has been applied to gold alloys and iron-base alloys containing small additions of precious metals. From the manufactured gold fibers, sintered structures were made for decorative applications. Additionally, it was found that due to rapid solidification during the fiber formation, precious metals can be finely dispersed in iron-chromium-aluminum (FeCrAl) and FeAl20 alloys . Good catalytic activity at elevated temperatures was found in compositions containing 3 wt.-% Ce and 0.5 wt.-% Pt.