Titanium anodising high voltage colors
twocr...@yahoo.com
I'm trying to get the higher voltage blue and green (top of the
voltages). I can get the colors but they appear dull - even on a mirror
buffed piece. The lower voltage colors - gold,purple,blue,yellow come
out great - you can 'see' the mirror finish through the color. I'm
using TSP/water as electrolyte. Anybody had the same problem - is this
just due to the extra thickness of the plating or should you be able to
get a mirror green finish?
Also has anybody tried plating Titanium Nitride over a normal Titanium
di-oxide color (the Titanium Nitride is that gold colored plating that
is put on tools like drill bits) to give it a hard finish over the
color?
pochino
<twocr...@yahoo.com> wrote:
> I'm having trouble anodising titanium 6AL/4V at the higher voltages -
> I'm trying to get the higher voltage blue and green (top of the
> voltages). I can get the colors but they appear dull - even on a mirror
> buffed piece.
What voltages? Above 110?
Clean distilled water in the electrolyte?
I've found that titanium (from Reactive Metals) doesn't produce those same
nice greens that niobium does at 120v and up (mains here is 220).
Something in the electrolyte burns itself onto the metal, as well, I think
--
Brian Adam
Auckland NEW ZEALAND
twocr...@yahoo.com
Yeah, the voltages are 110 and up, in fact I can go to about 200V but
the water I'm using is filtered by reverse osmosis from a drinking
water supply machine. I think that should be pure enough but I will try
to experiment with other sources. Is there any other electrolyte other
than Tri-sodium-phosphate that anybody has seen good results with? (and
is cheap and readily availiable. Funny that you should be from Auckland
Pochino, although I live in California now I was living in NZ and the
pendants I'm electroplating are maori hook/swirl/seawave style - small
world!
Peter W.. Rowe,
wrote:
Most of the anodizing i've done has been with Niobium. But I'm aware, as well,
that some of the times I've done it with Titanium, the colors tend to become less
intense with the high order colors (high voltage). That seems to be because at
high voltages, the oxide layer is much thicker, with interference effects taking
place through a layer thats many multiples of the operative wavelengths, rather
than the lower order colors, which start at a layer thickness of just the
wavelength of that color light. Seems to me that perhaps just the slight
reduction in transparency that would go with the layer being thicker, as well as,
perhaps, greater variations and defects in the layer thickness from point to
point, could easily account for the increasing muddyness/greyness of the higher
order colors. I'd guess the selective effect of the interference layer would
become less efficient with the thicker layers, thus less intense colors.
The other thing I've found is that the construction of your anodizer makes a
difference. If your anodizing power source is not well filtered for ripple, then
much of the power you pump into the piece is at lower voltages than the peaks of
the voltage cycles, and it does not anodizing, only increases the current forced
through the system, and that translates to heat. Poorly filtered power sources
tend to produce more heat at the anodized surface, and in the electrolite, which
seems to cause occasional "burning" or browning, sometimes in tiny spots.
This is more apparent when anodizing with a brush plater, or similar setup with
locally limited amounts of electrolite, than with an immersion bath setup, but
i've seen a difference in both types, over useing a power supply with good ripple
filtering.
Also, in my experience, though anodizing a polished surface is attractive, if you
want the most intense colors, anodize over a matte surface, such as a sandblasted
or acid etched one. The colors seem much brighter to me, over those textures,
than on a polished surface.
So far as I know, titanium nitride is usually deposited via vapor deposition, not
electroplating. Vapor deposition requires a surface to be able to hold an
electrical charge, to attract the deposited ions, but unlike electroplating, this
does not automatically mean it has to be electrically conductive at the surface,
so I'd assume one could apply TiN over an anodic layer. Whether it would adhere
properly, or whether it would totally obliterate the appearance of the anodic
color, I don't know, but I assume it would do both..
Peter.
pochino
We use dishwash detergent and rain water.
Just zaps a few bugs occasionally ;)
> Funny that you should be from Auckland Pochino, although I live in
> California now I was living in NZ and the pendants I'm electroplating
> are maori hook/swirl/seawave style - small world!
I was in and out of SF a few years ago, and even drove up to Portland and
drank some nice pinots there.
Cheers
Brian
--
B r i a n A d a m
e y e g l a s s e s j e w e l l e r y
Auckland NEW ZEALAND
www.adam.co.nz
Ted Frater
so far.
Ive been colouring titanium for many years and experimented with
electrical colouring befor I moved away from this way of doing it to
using heat.
1sstly your using what normally known as the "standard commercial
titanium" used for high strength low weight structures. If you can find
it you need to get hold of pure titanium 99.9% it colours so much
better. Now,I only use pure for my work.
When I tried using electrical colouring, I used ordinary car battery
acid. Well worth you trying just to see if it dowes give you the results
you seek with your alloy.
to move on
2ndly, to using heat,
you need a neutral slightly oxidising slow burning large diameter
propane torch 2 to 3in at least,mounted on a stand so the flame is
pointing vertically. a side effect is that a heat produced oxide layer
is very much harder and thus durable.
Polish your titanium to the degree you want , de grease and make sure
your tongs are clean and grease free too.
Light you propane torch and try out on a small piece first to get the
hang of it.
titanium is like stainless steel it doesnt conduct heat well, so you
need to place the item in the flame and move it around to get an all
over even temp rise ,just watch it happen. you will go through the
primary colours then when you get to the secondary you need to go much
more carefully as the colour change to temp ratio is much to close for
comfort!!"
the secondary blue is not so good as the primary but the secondary
mallard green is superb IF your very careful. If you go too hot youll
lose it and the oxide layer will pass beyond the opticaly refractive
phase and your then into a grey opaque zone. this is at a medium red
heat!!.Thus the need for tongs.
Thge largest item ive oxidised this way was a bowl some 20in in dia by
1/4in thick. That needed a propane burner some 12in in dia!
Picture available if interested.
Report back how you get on with this approach.
Good luck
Ted Frater Dorset UK.
twocr...@yahoo.com
- I will try it out although I only have access at the moment to a
small propane (DIY handyman style) torch...although since the pendants
are only 2.5'X.75' it may be sufficent. I'll let you know how it goes
in a couple of days. If you have a web link that shows that Ti bowl
anodised I'd (and everone else I'm sure) would be interested in seeing
it - sounds good.
If anyone else has any ideas for increasing duribility of colored
finishes on Titanium via overplating (either Ti Nitride or anythink
else) I'd like to hear about it.
Thanks to everybody on this thread - it's been very
helpfull/interesting - keep posting
Ben
twocr...@yahoo.com
becoming dull as the electroplating did. Very exiting. Only downside is
the colours are not as uniform because of the limited heat source I
have availiable.
Ben
Ted Frater
get one. And keep on experimenting