In article ,
says...



The parts are leaves in a leaf shutter for a 500W high pressure
mercury lamp optical system. The leaves sort of look like a sickle
with a short, really fat blade.

I don't care about warping when the leaf is hot. I don't want the
leaf to remain warped when it cools. The normal operating temp is
probably 200F but if there is a focus problem the leaf gets hot.
If even one leaf gets warped the shutter will jam. Which is bad.


It seems to me you the ideal material would retain its
strength at elevated temperature and have a low coefficient
of thermal expansion. Some stainless steels might be OK in
the strength criteria, but have relatively high
coefficients of expansion. Molybdenum would be a candidate,
though it will oxidize in the atmosphere at red heat. Moly
foil should be easy to get. Contact me offline if this
looks promising and you have trouble finding it.

Perhaps something like Kovar or Invar? This outfit looks to
have foil in some of the high temp alloys. It's not very
very convenient making direct comparisons on the site, but
it might tbe worth contacting them.

http://www.hightempmetals.com/technicaldata.php

Ned Simmons