From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Data sheet on the anodic treatment of 'Hiduminium' alloys, detailing the Bengough process.
| Identifier | ExFiles\Box 116\2\ scan0138 | |
| Date | 22th December 1939 guessed | |
| Data Sheet No. 38 THE ANODIC TREATMENT OF “HIDUMINIUM” ALLOYS UPON exposure to the atmosphere the surface of parts manufactured in “ HIDUMINIUM ” alloys, in common with those in most aluminium base alloys, acquire a protective oxide film. This, however, is extremely thin, being of the order of 0.0002 m/m.{Mr Moon / Mr Moore} thick. The properties of this film can be greatly improved by giving the alloy one of the electrolytic anodic oxidising treatments, which cause considerable thickening of the film up to a maximum of about 0.02 m/m.{Mr Moon / Mr Moore} In all the several electrolytic oxidising processes the aluminium alloy part is made the anode in a cell containing a suitable electrolyte and an electric current is passed, causing the aluminium alloy surface to be oxidised. Several patented processes are available ; the two most widely used are the Bengough and Alumilite processes.* THE BENGOUGH PROCESS, which is used chiefly for the anodic treatment of alloys of the Duralumin type, employs a 3 per cent. solution of chromic acid in distilled water at 40 ± 2° C. In most cases the operation is commenced by raising the voltage from 0 to 40 over a period of 15 minutes ; this voltage HIGH DUTY ALLOYS LTD. SLOUGH Telephone : SLOUGH 822/3 Telegrams : “ ALLOYS, SLOUGH ” P.T.O. | ||