Hi Paul. I’m glad that my description of the titanium dioxide formation was helpful to you. However, there is much, much more to the effects of heat on titanium. The grills that I make and sell are CP-2 titanium (commercially pure), and this essentially unalloyed metal pretty much acts like I described. Most of our ti pots are made from an alloy of aluminum and vanadium (type 5, or 6Al-4V). Most all of Rob Kelly’s QiWiz.net titanium products are made from 6Al-4V alloy. His wind screens are CP-2 however, because they need to be rolled up and not crack or break.
In a recent thread here, several guys much more knowledgeable than me about titanium metalurgy had described intricate details of the effect of intense heat on various alloys of titanium. Some ti alloys don’t revert back to the alpha crystalline phase when the metal cools back down past the beta transit temperature. Some will become brittle, others won’t. It’s all rather complicated, but the science is quite interesting (at least to me).
For the purposes of our discussion here, I don’t think there’s much to worry about when the metal takes on the patina from heating the pot without water in it. And I doubt that the physical properties of the 6Al-4V metal will be significantly altered, given what we use the pots for. Now, if we were to design a frame for a stealth bomber or a space shuttle or an unmanned space probe or a high performance mountain bike, we would need to use a very precise alloy of titanium.