Lo-Ex

Lo-Ex is an aluminium alloy with a very small thermal expansion co-efficient. It contains approximately 14 per cent silicon, 2 per cent nickel, and 1 per cent each of copper and magnesium.[1]

Applications

It has been used extensively and successfully over the years for all types of piston,[2] including in Hillman Imp,[3] and Terraplane[4] engines.

LM13 is a related alloy in the Lo-Ex series, also widely used for diesel engine pistons.[5] This alloy contains 12% silicon, 1% copper and 1% magnesium.[5] Both of these alloys have also been used in a strengthened form, reinforced by an MMC or hybrid composite of alumina or zirconium ceramic fibres. These alloys have been worked by squeeze casting or stir casting.[5]

References

1. Internal combustion engines illustrated. Long Acre, London: Odhams Press Limited. 1947. p. 85.
2. R. Munro (1978). "Wellworthy get it under control". Industrial Lubrication and Tribology. 30 (6): 224–235. doi:10.1108/eb053170.
3. "The Imp Engine".
4. "1936 Terraplane specifications" (PDF).
5. Smallman, R.E.; Bishop, Ray J. (1999). Modern Physical Metallurgy and Materials Engineering. Butterworth-Heinemann. p. 370. ISBN 9780750645645.