Electrodepositions on Tantalum in Alkali Halide Melts

摘要

Surface layers of tantalum metal were electrodeposited on steelfrom K_2TaF_7-LiF-NaF-KF melts. With careful control of the oxidecontents dense and adherent deposits could be obtained by pulseplating. In NaCl-KCl-NaF-Na_2CO_3 and NaCl-KCl-Na_2CO_3 meltscarbonate ions seems to be reduced to carbon in a single 4 electronstep. By electrolyses at a constant potential of – 1.4 V vs. Pt in aNaCl-KCl-NaF-Na_2CO_3 melt at 800 °C coherent carbon containingsurface layers could be obtained on tantalum substrates, when aCO_2 atmosphere was applied.