I really don't want to get the wire and then find out that if
I hammer it, it will lose the colors. Does anyone know?
Niobium is softer than steel, and hammers, etc. So is the oxide, at
least in terms of being able to withstand much tool marking. while
you MIGHT be able to do some limited, very gentle forging with highly
polished tools, and maintain acceptable color, it’s a bit dicey. The
oxide layer is not particularly workable. You can bend it, but the
stretching it will get from working the wire will tend to fracture
that layer. Now, small cracks in the color probably won’t be noticed.
But much more than that, or actual scratches, dings, nicks, etc, from
actually working it? Those will show. The key is the question of
how much degredation in the color are you willing to accept?
Please also consider that actually recoloring the wire is simple to
do, if you’ve got a power supply capable of generating the required
voltages. Now, you can spend big money buying such a supply. but a
power supply capable of anodizing niobium is easy to make if you can
locate a variable transformer (also called a powerstat, or variac).
These are the things that also are used to vary the voltage in normal
electroplating supplies, so if you have such a thing, you can modify
it without too much dificulty, to allow you to also anodize niobium.
There are, of course, safety concerns to be addressed. Anodizing
niobium (or titanium or other reactive metals) used voltages in the
100 to 170 volt range, often as not, and these voltages are high
enough to be dangerous if you don’t handle them with respect. But
this is mostly common sense and a respect for the electricity, and not
doing things that expose you to the danger of shock. This is not hard
to do. The modifications needed to tap off higher voltages from a
normal electroplating supply are just a couple cheap diodes you can
get at radio shack or any other electronics supply firm. Cost is just
a few dollars for the simplest setup, which will still work just fine.
You can get fancier with the addition of filters, or voltmeters for
repeatability, but it’s not essential. And the chemicals involved are
completely safe. Set this arrangement up once, then you can buy
unanodized wire, work it to your heats content, and then color it as
you wish after you’ve worked it. A lot more versatile than buying
precolored wire.
It’s getting too close to my bedtime tonight to go into more detail,
but if people are interested, and don’t already know how to build or
modify a power supply to anodize reactive metals, I’d be happy to
write it down for anyone who needs. Like I said, it’s simple.
Peter Rowe