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Niobium & metal clay

#1

Aloha,

Has anyone tried to use Metal clay (artclay or pmc) with niobium? I
wantedto use the anodized niobium with the metal clay but wasn’t
sure it the silver would fuse with the niobium.

Mahalo in advance for all your Melanie

#2

Hi, Melanie,

You were right to have doubts! Niobium will not fuse to other metals
in an oxygen atmosphere, and heat will ruin the color. You must cold
joint niobium or titanium to any other metal.

Have fun!
Noel

#3

Melanie,

The silver will not bond to the niobium surface, you will need to
make a mechanical lock to hold it. I think the niobium will turn
black at the temperature it will be exposed to in the kiln.

James Binnion
James Binnion Metal Arts

#4 
Has anyone tried to use Metal clay (artclay or pmc) with niobium?
I wantedto use the anodized niobium with the metal clay but wasn't
sure it the silver would fuse with the niobium.

It won’t fuse, as the oxide layer on the niobium prevents metal to
metal contact, and thus fusion. You can join parts, though, by
shaping the niobium in such a way that the art clay is mechanically
locked to the niobium. For example, if you put a couple holes in the
niobium, and the art clay goes through those holes so it’s on both
sides of the niobium, after firing, the two are essentially riveted
together.

Your bigger problem is that the heat of firing the art clay will
give you a very thick oxide layer on the niobium, such that any color
you’d put on the niobium would be destroyed. If you wanted a dark
grey to black niobium surface, this might be OK. If you don’t then
you’d have to remove that oxide layer from the niobium, perhaps by
grinding, or with HF acid (very very dangerous to use, so not
recommended at all) I’m not sure whether Reactive Metals “Multi
etch” would be able to get through that type of thick oxide layer.
Sand blasting (with an abrasive harder than sand) might also work
fine. Anyway, once you’re back to clean niobium with it’s normal thin
oxide layer, you could then anodize it for color. But here too, there
are problems. The silver is highly conductive, and you’d have to
totally insulate the silver from the anodizing solution or the silver
will take current flow away from the niobium, preventing the niobium
from coloring properly, especially in the area right next to the
silver. You can get around this fairly easily by brush painting for
anodizing, rather than immersion anodizing, but even then, the
sections right adjacent to the silver may be difficult.

#5

Long, long ago when the first masters classes were being taught I
made some large rings out of probably 14ga Titanium. I then wrapped
the joining ends with silver PMC and fired them. The connection
seemed secure what with all the shrinkage of the early PMC. The thing
of interest was the heavy oxidation of the Titanium. It actually
looked like ceramic, beige to brown. Very interesting appearance.
Totally un-anodizable.

Bill

Bill, Deborah, Michele & Sharon
Reactive Metals Studio, Inc.

#6 
Sand blasting (with an abrasive harder than sand) might also work
fine.

In my experience, even glass bead will remove the usual kind of oxide
layer. But as Peter said, “even here, there are problems”. Unless
your niobium layer is quite thick, you may get the result I get on
titanium: The increased surface area that results from sand blasting
(I guess that’s the reason) causes the blasted area to dome/bulge
outward. A cool effect at times, if you want it, but not terribly
predictable of controllable without experimentation.

Noel

#7

Which you could then sgrafitto and re-anodize by brush.

Kay Alklen

#8

Or anodize the niobium and fire the clay separately and then join,
or bezel set the anodized niobium on the clay.

Kay Allen

#9 
Has anyone tried to use Metal clay (artclay or pmc) with niobium?
I wanted to use the anodized niobium with the metal clay but wasn't
sure it the silver would fuse with the niobium.

Melanie, have a look at how Holly Gage incorporates titanium into
her PMC jewelry. What an inspiration! Her website is (as expected)

Lorraine