M. Eversberg II wrote: |
Titanium is quite hard. It's quite light, too. This is why it's not good for swords. |
But weight isn't the problem. Titanium is just not very hard, perhaps a little harder then aluminium alloys (though I don't have the figures at hand), but certainly not anywhere near heat treated steels. The reason why titanium is used in aircraft is purely because for structures which undergo raised temperatures, you can make them lighter from titanium then from aluminium. Aluminium looses it's strength rapidly if you raise the temperature, while titanium doesn't. So if you've got f.e. a Concorde, which due to it's flying speed gets (or got) heated up to 150C (not by friction b.t.w.!), titanium is the better option. For slower flying aircraft, it's aluminium.
What people mostly think of regarding titanium, the gold colored coating on tools, is actually titanium oxide. That's quite hard and brittle, and therefore not suitable for swords either.