| 摘要 |
1,243,877. Metalliding aluminium surfaces using fused electrolyte. GENERAL ELECTRIC CO. June 16, 1969 [July 1, 1968], No. 30284/69. Heading C7B. Metallide coatings of metals selected from Li, Be, Mg, Sc, Y, La and other rare earths e.g. Ce, Ac and other actinides e.g. U, Hf and Zr, are formed on Al metal or alloys in a fused electrolyte cell in which the Al metal or alloy as the cathode is joined through an external electrical circuit to one or more of the metalliding metals as the anode; the fused electrolyte is composed of chlorides and/or bromides with or without fluorides of Group IA and IIB i.e. alkali and alkaline earth (including Be and Mg) metals, and 0À01 to 100 mole % of a halide of the metalliding metal, and is maintained at a temperature of at least 350‹ C. but below the M. P. of the Al or the alloy coating being formed thereon, in the absence of oxygen e.g. by using a vacuum, nitrogen or one of the inert gases; and the current flow is controlled in the cell so that the C. D. of the cathode does not exceed 10 amp/dm<SP>2</SP>; an applied e. m. f. not exceeding 1À0 volt may be connected in series with the external circuit. Combinations of the metalliding metals can be diffused into the Al surface simultaneously and/or sequentially. Examples of electrolyte are (1) BaCl 2 , KCl, NaCl and CeCl 3 to form aluminium ceride; (2) BaCl 2 , LiCl and YF 3 for yttriding; (3) MgCl 2 and KCl to form an alloy of Al and Mg; and (4) BaCl 2 , KCl, NaCl and UCl 4 for uraniding. Initially, electrolytic clean-up runs are effected against Ni strips or screens as cathodes to remove impurities from the electrolyte. |
