I'm not
aware of a resistance element that'll go any higher then
~2300 degrees, that being enough to melt brass or prolly even pure
copper.
Tungsten in a sufficiently inert atmosphere will get white-hot without
problem - that's how incandescent light bulbs work.
The melting point of tungsten, according to what information I can
find, is somewhwere around 3400?-3425?, and assorted resources claim
it's the highest melting point of any metal (and second-highest
element, after carbon). They don't mention whether there are alloys
with higher melting points.
I don't know about alloys, but there are definitely *compounds* with
higher melting points.
Peace... Sridhar