RE: [ATM] Astronomium Metal Mirror

[Anthony Stillman <atmer@flash.net>]

In my researching speculum I came across a range of alloys generically
called magnalium.  Magnesium and aluminum form several different
inter-metallics.  Variously alloys are tabulated as having the following
properties.  An 83 percent reflectivity across the visual spectrum.   A
coefficient of thermal expansion  0.24   Density, 2 grams per cubic
centimeter.   And a coefficient of thermal conductivity about a fifth less
than that of aluminum.   It's softer than aluminum too.  It can be cast to
a mirror finish.  It can be diamond cut to a mirror finish.  Today it's
used in pyrotechnics (it burns good) and for insect screening as it is
resistant to corrosion.

If I come by a piece large enough to polish, I will try.  I expect that
that way of finishing will be some what of a challenge.

Anthony



trium mensum molita cibaria

Loosely:  A solder's pay
Meaning:  A three months' supply of ground grain.
Literally:  Three months' labor worth of edible rations.


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