Improvements in the deposition of chromium on antimony or antimony alloy surfaces

摘要

738,236. Electrodeposition of chromium. GENERAL MOTORS CORPORATION. Sept. 3, 1953 [Sept. 22, 1952], No. 24349/53. Class 41. A method of depositing chromium on a surface of antimony or antimony-base alloy comprises immersing the surface in a hot chromic acid plating bath for a period of not more than one minute and subsequently electrodepositing chromium on the surface. The bath in which the surface is immersed may be the same as or different from that used to deposit chromium, and comprises an aqueous solution of chromic and sulphuric acids. The temperature should be between 110‹ and 160‹ F., and the immersion time is preferably between 5 and 30 seconds. The cathode current density used for the plating is preferably between 150 and 265 amps. per square foot. Specification 738,228 is referred to.