On Monday, December 8, 2003, at 07:31 AM, Dominic-Luc Webb wrote:
Tungsten is strong for its thickness, but generally is very, very
thin, as in light bulbs.
Try TIG welding electrodes.
However, the nichrome and kanthal wires
are commonly much thick so are quite strong. Reduced form of
aluminum goes to melts at slightly above 500 degrees. It is
not clear to me that the temperature ratings you mention are
the determining factor in choice. I rather like the strength of
highly re-usable things like car cigarette lighters and kanthal
wires.
Perhaps there are specific tungsten electrodes one would suggest?
Perhaps someone knows there is in fact a reason to not use these
other options?
The issue is whether one wishes to evaporate pure aluminum, or also
evaporate aluminum and some of your heating element with it, contaminating
your mirror coating. Tungsten's extremely low vapor pressure even at
high temperatures makes this very unlikely. The same cannot be said
for Nichrome. I don't know what is in Kanthal and I'm too lazy to
Google for it, but I do know you don't want to sputter your mirror
with nickel (an ingredient of nichrome).
