When I was in junior high I had this guy vehemently proclaim to me that titanium was an alloy of iron and aluminum. LOL What a joker, it's on the bloomin' periodic table!
I remember this because I went on to become a metallurgist.
If you'll bare with me, I tend to get professorial...
'Titanium' tends to get treated with a broad brush... like steel this is gross oversimplification. YMMV. Ti and its alloys are *not* the answers to everybody's problems.
Rigidity of a material is determined by its elastic modulus, which is the same idea as the constant of a spring (Hook's Law, remember that?). Ti and Ti-alloys are actually rather low in comparision to Fe-alloys in this regard....
Fe and mild steel: 196 GPa
Ti-alloys: 80-130 GPa
If you're speaking of strength, meaning the resistance of the material to plastic deformation (permanent deformation, elastic deformation goes away after the load is taken away) then Ti alloys and steels are all over the map. The strongest steels are far ahead of the best Ti alloys with regard to strength at room temperature.
What Ti has going for it is lower density, corrosion resistance, and in some of the aerospace alloys retention of strength at high temperature. Usually for the same load bearing capacity, a Ti-alloy component will be lighter than a steel one.
Some Ti-alloys have small amounts of Fe in them. As far as I understand it the main reason is so that they can use less expensive master alloys (master alloys are the things weighed out and thrown into the crucible to actually make a melt of an alloy... many of them contain fair amounts of Fe). Add a lot of Fe to a melt of Ti and you are asking for trouble. Different crystal structures will form upon solidification that are intrinsically brittle.
Spock's World is the novel I believe you're referring to aerius. Star Trek is rife with fantasy metallurgy and materials science... transparent aluminum, trititanium, dilithium, and the ever handy "element/particle of the week (TM)".
[This message has been edited by GrantP (edited 02-17-2001).]