March 22, 2011
Is it possible to color titanium in an oven (to control the temperature)? If so, what temperature does the oven have to have?
Assuming a kitchen oven, the answer is, No.
If you have a laboratory oven, a kiln, or some such, then the answer is, “Probably”.
Titanium colors by heat are controlled by temperature much like anodized color is controlled by voltage. The temperature at which you should start seeing the lowest tan/bronze is about 640°F. This is easy to reach with a direct flame, but not in a household oven.
I have not found a color/temperature scale, but would love to publish one. If anyone with a lab oven wants to play with this, please share your results.
March 4, 2011
I’m trying to get a black or dark gray finish on the face of a titanium driver head. What voltage achieves that color?
Sorry, John. Anodizing produces a particular spectrum of colors limited by the first two octaves of optical interference. I explain it here.
Black and gray are shades, not colors. One cannot make titanium black by anodizing.
So, how is black titanium made? Everyone who does it is keeping the actual process a tight secret. But my educated guess is that it is produced by implanting nitrogen into the titanium using an industrial vacuum effusion furnace. This produces a relatively thick layer of titanium nitride in a similar chemical manner that titanium dioxide is made by anodizing. But nitrogen implanting cannot be done in an oxygen rich environment, like air or water. Air is 21% oxygen by volume, and water is 33% oxygen by atoms, or 88% by weight.