抄録
Chromium crystallizes in various crystal forms, namely, dendrites and platelets, by electrorefining in a bath of fused salt of 1 : 1 NaCl–KCl containing the trivalent chromium. Crystallographic investigations of these crystals have been carried out. Generally, crystals are bounded with low-index natural facets : i.e., (100), (110), and (111). On the facet (110), however, there are three distinct stripes parallel to either ⟨001⟩ or ⟨112⟩ and ⟨552⟩ directions. Twin growth with the twinning plane (11\bar2) is frequently observed, when crystals grow in the ⟨110⟩ direction in the (111) plane or in the ⟨111⟩ direction in the (110) plane. In the molten-salt electro-refining process, both preferential tendency of the orientation and mechanism of the crystal growth should depend strongly on the three factors : i.e., the cathode current-density, the salt-bath temperature, and the electronic structure of metals. In this report, the relative effects of these factors are discussed tentatively.
