Subject: Welding Titanium

From: [email-masked]
Date: Fri, 17 Dec 1993 07:45:01 GMT

Anyone out there have any good hints for welding titanium?
A friend and I are designing and building a racing suspention for a 
snowmachine and are considering using titanium for the frame.
Any work we will be doing will be done using TIG welding and we are
considering building a purge tank to do the welding in.  We have the skill
and the equipment but lack the experience.  Your advice would be appreciated.
 
Brandon France
[email-masked]

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From: [email-masked] (Roy Giacchino)
Date: 18 Dec 1993 23:02:58 GMT

>and the equipment but lack the experience.  Your advice would be appreciated.

    Your request sparked my curiosity so I'll ask .. How does one 
   cut a peice of titanium ?  What would the cutting material be ? 
   How about drilling the stuff ? What kind of drill bits would be 
   used?  Just wondering. Thanks.

                             -- roy

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From: [email-masked] (Dan Rubesh)
Date: 19 Dec 93 00:18:55 PST

[email-masked] (Brandon France) inquires:
                                         
>>and the equipment but lack the experience.  Your advice would be 
>>appreciated
>> 

>    used?  Just wondering. Thanks.

Titanium can be cut by a number of conventional means.. It isn't so much a 
hard material as a tough material.. Titanium is actually relatively soft, 
and has some plastic deformation characteristics that can make it 
challenging to machine.. It can be best turned / milled with carbide 
inserted tools, high positive, high shear geometry, on the order of 15-20 
degrees top rake seems to work better.. Drilling is done with carbide, 
cobalt, or high speed steel drills.. Cutting speeds are relatively low, 
around 50-60 surface ft/min for high speed and <150 sfpm for carbides (this 
from memory as my Metcut book is at work).. Probably the most difficult 
operation to perform on Ti in my experience is tapping, as the plastic 
deformation characteristic tends to make the material try to go away from 
the tap while it is being driven into the hole, and when you reverse the 
tap to remove it, the Ti hangs onto it like grim death.. Among the better 
cuting fluids that I've used with it is Westlube / Anchorlube (a.k.a. 
`parrot shit' in the shops I've worked in).. Titanium is also a flammable 
material, much like Magnesium it will maintain it's own flame once lit.. 
It's about twice as difficult as mag to get started burning, and about 3x 
harder to put out.. One aerospace machine shop that I worked in some years 
ago used to routinely weld Titanium with an Electron Beam welding process 
in a vaccuum chamber.. I'm not sure it can be easily welded with TIG, and 
my area of experience is more in the cutting than the welding arena.. Most 
likely a welding type will be able to answer that question better..

--
Good Winds and Tight Lines!

Dan Rubesh                   AKA Member/Merchant     Wind Wizard, Purveyor of
UUCP: {ucsd, nosc}!crash!danr       GO               Stunt Kites & Accessories 
ARPA: [email-masked]          FLY A             P.O. Box 5747    
INET: [email-masked]           STUNT             Ventura, CA  93005
(805) 659-5654                     KITE!             Member: Kite Trade Assn.

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From: [email-masked] (Jim Berilla)
Date: 19 Dec 1993 21:40:48 GMT

In article <1993Dec19.001855.29969@crash>, [email-masked] (Dan Rubesh) writes:

[lots of good stuff deleted]

There are a lot of titanium alloys in use, and the ease of machining them
varies greatly.  CP (chemically or commercially pure) titanium is a dream
to work with.  6Al4V (6% aluminum, 4% vanadium) can be a nightmare.  The
problem with 6Al4V is that it work hardens quickly.  If you let the tool
kiss the surface without cutting, the surface will harden.  Then it's like
cutting through case hardening.  Carbide tools help a lot in this case.

Another weird thing about titanium, is that the chips are very sharp for
some reason.  I couldn't believe how sharp they were, but I have a scar
on my index finger from trying to clear a chip on the lathe.  The chip
cut down to the bone, and the lathe wasn't even running.  (It was 22 years
ago.  I know better now.)

|>                                              Titanium is also a flammable 
|> material, much like Magnesium it will maintain it's own flame once lit.. 

Save those chips.  The pyrotechnicians use them for (surprisingly) titanium
salutes.  Bright flash, lots of sparks, bit noise.

-- 
      Jim Berilla / [email-masked] / +1 216 368 6776

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From: [email-masked] (Dan Rubesh)
Date: 19 Dec 93 00:18:55 PST

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From: [email-masked] (Jim Berilla)
Date: 19 Dec 1993 21:40:48 GMT