Re: Cold-tolerant insulators?

Paul Ciszek wrote:
>
> I need to make some spacers out of a non-conductive material that
> will not crumble when chilled with liquid nitrogen. I'm not looking
> for anything to remain flexible or anything, just to tolerate the
> temperature cycling without damage. How well does phenolic, for
> example, take this kind of treatment? How about teflon?

How big is the spacer lump? Solid or lattice? Will it be subjected
to mechanical shock? How strong must it be? Is it easily
replaceable? Cut out an automobile catalytic converter honeycomb.
An annealed Pyrex form from your glassblower would do it, as would
acrylic, polystyrene, or TPX. If dimensions are critical look at
fused silica, Zerodur, or Corning ULE.

Dense polystyrene foam is pretty good, too, but it is not strong
against compression. Cut with a hot wire.

Teflon is out. It has a whomping huge TCE phase transition at 16 C
and large LCE/degree elsewhere

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf
.

Relevant Pages

  • Cold-tolerant insulators?
    ... I need to make some spacers out of a non-conductive material that ... will not crumble when chilled with liquid nitrogen. ... pciszek at panix dot com | indistinguishable from malice." ...
    (sci.materials)
  • Re: Cold-tolerant insulators?
    ... >Paul Ciszek wrote: ... >> I need to make some spacers out of a non-conductive material that ... >> will not crumble when chilled with liquid nitrogen. ... Styrofoam is not dimensionally stable--it squishes. ...
    (sci.materials)