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 the analysis and comparison of different piston aluminum alloys.
| Identifier | ExFiles\Box 76\3\ scan0064 | |
| Date | 9th July 1918 | |
| RR. 864b. ROLLS-ROYCE, LIMITED. L420 LABORATORY REPORT. To EH works Date 9th July 1918 Re Piston Aluminium alloy specially that used in the Berry pistons Ref. R/98718 under pistons also R4/14718 received by laboratory on Laboratory tests made some months ago on a similar alloy to the Berry pistons i.e. L48} Copper 5.8% Zinc 11.6% - Iron 1.03% Silicon .32 gave under our comparative heat conductivity test (see report L-376 26th July 1917) a value of 66 as compared with commercial aluminum 100 & our present Y Copper piston alloy of 77. I also made an alloy today containing Copper 6.1% - Zinc 11.8 - Iron 1.32. this did not cast very well being rather Crakle & scum partiness. Its heat conductivity was found to be 62 : it would therefore get hotter than our present piston alloy i.e about 24% while at the same time L48} gave a tensile strength of only 3.8 tons at 390°C as compared with 6.1 tons with our present alloy at the same temperature. Signature HBH | ||