| 摘要 |
834,714. Anodizing aluminium. IMPERIAL CHEMICAL INDUSTRIES Ltd. Sept. 5, 1958 [Sept. 11, 1957], No. 28630/57. Class 41. An anodic coating is produced on aluminium or aluminium alloy wire or strip by using an alternating current of a frequency between 100 cycles per second and 300,000 cycles per second. The preferred range is 2000 to 10,000 cycles per second. The temperature of the electrolyte is preferably maintained at 50‹ to 75‹ C. A D.C. component may also be included. In an example, aluminium wire of 0.035 inch diameter was anodized in 10% v/v sulphuric acid at 55 ‹ C. with a current density of 10 amps/ sq. in. of wire surface. The frequency was 5000 c/s. and the duration of the treatment at any point on the wire was 30 seconds. The flexibility of the coating so produced is compared with that of coatings produced by D.C. and mains-frequency A.C. methods. |
