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).
Comparing 'Y' alloy with a proposed 'T50' alloy for use in forged aluminium pistons.
| Identifier | ExFiles\Box 66\1\ scan0161 | |
| Date | 19th December 1927 | |
| BY.{R.W. Bailey - Chief Engineer} from HL. c. BJ. R.{Sir Henry Royce} c. to Wor.{Arthur Wormald - General Works Manager} Hs.{Lord Ernest Hives - Chair} c. to RG.{Mr Rowledge} Laboratory. HL2/EJW19.12.27. RR. FORGED ALUMINIUM ALLOY PISTONS. X.4004 X.3996 X2748 X.8040 The 'Y' alloy pistons which have been tried out are not entirely satisfactory and are expensive. One trouble is that they tend to have local oxidation flaws; they are also liable to a type of brittleness in thin sections. The primary advantage claimed for 'Y' alloy is high tensile strength at the maximum running temperature. In view of the above and also as a result of tests it appears that a somewhat lighter alloy similar to the one which is being tried out for all light alloy castings on the F.XI. engine, would be better for pistons. The following points may be noted in respect to this alloy, which has been designated "T50" :- (1) It produces much finer grain castings than 'Y' alloy, and is less liable to surface oxidation. (2) It forges quite as well as 'Y' alloy. (3) It can be produced of similar strength at the running temperature. (4) It is less liable to internal oxidation and brittleness. (5) It can be heat-treated at a lower temp. or at a similar temperature to 'Y' alloy, giving similar results. (6) It machines well, is somewhat lighter, and is relatively good from the corrosion and heat conductivity standpoint. If required the 'T50' alloy could be used for producing die-castings for pistons. HL. | ||