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).
Laboratory report on low-voltage anodic oxidation experiments conducted on R.R.53 pistons.
| Identifier | ExFiles\Box 86\2\ scan0283 | |
| Date | 22th October 1934 | |
| To Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} HL1/AG.22.10.34. Laboratory. Re: Anodic Oxidation of R.R.53 Pistons. We have carried out low voltage experiments in connection with the above and have now treated two used Pistons supplied by you. Throughout the tests we have been unable to obtain a film of thickness greater than 0.0003", due, there is little doubt, to the resistance offered by the film during electrolysis. The electrolyte selected was that which made the least dimentional change to the test pieces, the tendency being for a reduction of approx. 0.00025" in diameter, (it is to be noted that the piston ring stops have been badly attached). We send the two pistons herewith. They have been oiled (to saturate the oxide film and thus exclude water) and we would point out that the film on these is thinner than those on pistons we have examined from outside. We think that a comparatively high tension current generator would give us a wider field of investigation, but one difficulty at the moment, we understand, is that of finding a situation for such a generator and other apparatus. Will you kindly let us know whether you require further pistons treating by the present method, and the result of your findings with regard to them, also whether you wish us to carry out experiments at a higher voltage with a view to obtaining thicker coatings. Hl. HE | ||