Archived posting to the Leica Users Group, 1998/09/20
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From: Dan Cardish <dcardish@microtec.net>:
>Well, someone who has been a machinist since 1964, and who has worked=20
>with titanium has told me that it has about the same machinability as=20
>steel, but is more difficult to weld, and the cost of titanium is about
>the same as alloyed steels. I am taking his word for it.
Then explain why custom-made Ti fasteners are far more expensive than
Al or 4130 CrMo steel equivalents; why Ti ice pitons are often twice the=20
price of equivalent (same country of origin) steel ones; why a Ti bike
frame is nearly always more expensive than equivalent CrMo steel one;=20
why golf clubs with Ti heads are more expensive than similar ones with=20
steel heads; and why an M6 Ti or F3 HP Ti cost more than their non-Ti
equivalents.=20
If what you say were true, Ti would simply replace steel (and Al) in many
applications due to its high tensile strength, excellent corrosion=20
resistance,and superior resistance to fatigue-related failure. For the=20
most part it hasn't, because it costs more than 4130 steel or 7075 Al,=20
and low cost is usually a design goal. You can bet that if Ti cost the=20
same as steel, engineers would specify it more widely than they do!
Let's use an even more concrete example: consumer automobiles would=20
benefit in many ways from the use of Ti (and epoxy-resin composites),=20
but Al, CrMo steel, and thermoplastics are used instead.=20
In military aircraft, which are designed with less regard for cost, the
former materials are used rather extensively.=20
..........................................................................
Alexey Merz | URL: http://www.webcom.com/alexey | email: alexey@webcom.co=
m
| PGP public key: http://pgp5.ai.mit.edu/ | voice:503/494-684=
0
| "That pig. He eats french fries like I drink whiskey and=20
| smoke cigarettes. I don=92t begrudge him his fries, but he=20
| didn=92t offer to share them. It was beyond greed, the way =
he
| buried his face in this little red plastic basket. It=20
| shocked me." =97 Dr. Hunter S. Thompson, on Clin=
ton