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Hi everyone,

I'm doing a materials analysis on the materials used for Stirling
engines and need a place to start. What types of exotic materials are
needed in stirlings? Which aspect of the engine requires these
materials? What are the material specifications (thermal expansion,
max temperature)?

All these questions are geared toward stirlings that are coupled with
parabolic dish (solar) as the heat source. (1kW, 3kW, 25kW)

My motivation is to find substitution materials in order to reduce the
expense of a Stirling.

Huy

The materials of the Hot End are of paramount importance to withstand the high temperatures required to achieve the maximum heat transfer to the inside of the Stirling engine. They must also withstand high internal pressures at these temperatures. The rest of the engine should be able to stand exposure to ordinary outdoor weather conditions consistent with an extended life expectancy.

And, of course, my two cents worth.

While Bill is totally right in his guidelines for metal to withstand the high heat on the hot end, etc ....

As a general concept, the Stirling really requires no special materials. The excessive cost that makes them impractical is in the finicky nature of the moving parts. The precise machine work required at this point in the Stirling's timeline of development is the thing that drives the cost up, to make it not economical.

Holding back the Stirling is NOT a lack of some special rare earth element or even theory of what can be gained in a perfect engine.

The cost reduction attack is best focused on good old fashioned manufacturing engineering, not science.

Make a brand new Stirling work great, before you move on to making one last a long time.

- Joe

Great answers, keep them coming!

I think that its a combination of both. The low tolerances and the materials (withstanding; thermal fatigue, high temp, low thermal expansion). What do they currently use for the regenerator, hotside, piston, etc.?

Huy