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 piston metals, comparing various alloys through engine, conductivity, and mechanical strength tests.
| Identifier | ExFiles\Box 76\3\ scan0013 | |
| Date | 20th July 1917 | |
| ROLLS-ROYCE, LIMITED. RR. 5646 L 376 LABORATORY REPORT. To: Mr Royce, Mr Wormald, Mr Whitehead, Mr Bailey & Mr Kestevon, Mr Clark Date: 20th July 1917 Re: Piston metals in the light of recent experimental work - Engine tests, conductivity tests, mechanical strengths of the various alloys - About a year ago the report by the Alloys Research Committee recommended an alloy containing 14% copper & 1% Manganese since the alloy kept exceptionally stiff up to 370°C. Recent work has shown that, the alloy & also the 12% copper alloy now in use, both have a low heat conductivity figure & that this factor has a vital influence on the temperature of piston crowns. The high copper alloys are also inherently brittle especially at from ordinary temperatures to 200°C. At about 320°C (present piston temp) they also tend to weaken in time owing to crystal or grain growth. (observed in run pistons). Conductivity figures in relation to tensile strength & composition are given on the next page. The tensile strengths & ductility are given for the range calculated to exist under piston conditions for the various compositions & their respective conductivity. Signature: HeS | ||