Titanium is neat stuff, but a very funny metal. The reason why it is impervious to normal corrosion is that it instantly reacts with other metals, and with the atmosphere, to form a passive layer. When it's in the course of being shaped, or cut, though,the fresh bare metal tries to react with whatever's touching it. Grind it, and it will make brilliant white hot sparks. Try to form bare metal, and it may well stick to the tool, and rip up harder metals. We normally buy titanium wire coated with moly lube, to make it form consistently, then have it etched to clean it.
One engineering prof told me, when machining titanium, always try to make a chip. If you let the cutter pause, the Ti will try to bind to it and usually damage the tool.
Titanium is non-toxic and hypoallergenic after it is cleaned, and is frequently used for body implants. CP and 6-4 are the most common grades, and 6-4 can get up to about 150,000 tensile, which is not unlike many 4140 gun steels. There are also stronger grades like Beta C that we use for springs, but they are typically well over $100/lb.
Caspian Arms has made titanium 1911 frames for a while, but not the slides, as the slide is just too hard to machine from that metal.
Last edited by tex_n_cal; 10/19/12. Reason: last sentence
