source for small qty of high Si Aluminium barstock

[kenre]

Im trying to locate, with no luck in Australia, a small quantity of 35mm OD round, 20 to 30% silicon aluminium for piston material for small 2 stroke engines. Aprox 300mm length
Can anybody help?
Ken

 

[unclesyd]

The alloy you are looking for was developed by NASA at the MSFC and is called MSFC 398. I don’t have it listed at any of my sources. It seems to be only produced by the people who have are licensed by NASA.

There are several other Silicon Based Hypereutectic Al alloys at the following site with a Japanese JIS Number

http://www.samkrgpistonsandrings.com/pistonspecs.htm

 

[unclesyd]

The only references I've found for this material is for castings, mostly of the permanent mold variety. Which you would expect for pistons.

Here is a paper from the NASA Technical Transfer office about the high Si-Al alloy you might give them a call. All my dealing with NASA have been very cordial and informative.


techtran.msfc.nasa.gov/tech_ops/nasa388alloy.pdf

 

[kenre]

Thanks for the links,
but not quite what im after.
I plan on machining the pistons from the barstock.
The higest silicon content i could see was 17% ?
There is bar available here in 21 and 30%, but only in 20 and 25 mm diameter. my pistons will have finished size of 30mm.
It will be a taper fit to the liner, no rings, Running in a hard chrome plated brass liner. Standard practice for this type of engine.