Author Topic: Milling Titanium  (Read 18296 times)

Offline DaveH

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Milling Titanium
« on: June 12, 2011, 05:57:10 PM »
Hi,
Has anyone done any milling of Titanium.

I’ve cut it on the lathe using HSS cutters (sharp) – not too problematic. (Apart from the occasional fire) :doh:

Milling it however, I just could not get it to cut properly.  :hammer:

Small grooves only .003” deep using a 1mm dia mill. I even tried with some engraving cutters, still not successful.

Anyone done it, and would you like to share the secret. :bow:

 :beer:

DaveH
(Ex Leicester, Thurmaston, Ashby De La Zouch.)

Offline John Stevenson

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Re: Milling Titanium
« Reply #1 on: June 12, 2011, 06:05:07 PM »
Depends on grades,
I make some pump shafts out of Titanium as it's the only thing ferric chloride won't eat. I buy grade 2 as it's the best I have found for machining [ and the cheapest ] It machines a lot like stainless, milling and turning is OK but drilling and tapping can be a pain as it wants to grab and work harden.

Was given a bit of grade 9 for a job and it was harder than a witches tits.

John S.
John Stevenson

Offline DaveH

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Re: Milling Titanium
« Reply #2 on: June 12, 2011, 06:09:59 PM »
John S,

Seems like you and me are the only ones here. :D

 :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol:
Was given a bit of grade 9 for a job and it was harder than a witches tits.
John S.

WHOT! - sure you are alowed to say that? :D :D :D

DaveH
(Ex Leicester, Thurmaston, Ashby De La Zouch.)

Offline doubleboost

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Re: Milling Titanium
« Reply #3 on: June 12, 2011, 06:14:54 PM »
I have a friend who makes titanium exhausts for racing cars i have seen them milling manifold flanges .
It seems to machine like stainless . Iwill ask them what grade ect
Not machined any witches tits but i would think lots of cutting fluid would be needed  :doh: :doh: :doh:

Offline spuddevans

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Re: Milling Titanium
« Reply #4 on: June 12, 2011, 06:17:06 PM »
I have milled titanium, what I've found works best is to use carbide cutters, or if using hss, don't let the cutter rub as the stuff I have work hardens in the blink of an eye. I use light cuts, but that may be down to my mill being a little more flexible than I'd like.

The smallest size of cutter I've used is a 2mm carbide, and I have also used a carbide V-point for engraving using extremely shallow cuts, with a little bath of thin cutting oil.

Tim
Measure with a micrometer, mark with chalk, cut with an axe  -  MI0TME

Offline DaveH

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Re: Milling Titanium
« Reply #5 on: June 12, 2011, 06:18:05 PM »
John S,
Cuts fine on the lathe, never drilled or tapped it.
Milling - seems I am doing something wrong.

How should I mill it.
I should point out I don't use any coolant, sometimes use some cutting fluid to help.
However nothing seemed to help when milling it.

DaveH
(Ex Leicester, Thurmaston, Ashby De La Zouch.)

Offline doubleboost

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Re: Milling Titanium
« Reply #6 on: June 12, 2011, 06:25:00 PM »
It welds nice with tig  :D :D :D
I had some off cuts of pipe i used them on my diy gas turbine
Once welded it is hard  :( :( :(

Offline DaveH

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Re: Milling Titanium
« Reply #7 on: June 12, 2011, 06:29:28 PM »
Tim,
I have tried cabide engraving cutters .003" depth of cut with cutting fluid, without cutting fluid still didn't come out right. All rough and raggity.

Could I have the spindle speed too high, do you think?

 :beer:

DaveH
(Ex Leicester, Thurmaston, Ashby De La Zouch.)

Offline DaveH

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Re: Milling Titanium
« Reply #8 on: June 12, 2011, 06:34:57 PM »
Doubleboost,

Hey, try to keep focused on the problem.  :wack:    :D :D :D


(I'm just pulling your leg)  :)

 :beer:

Dave
(Ex Leicester, Thurmaston, Ashby De La Zouch.)

Offline doubleboost

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Re: Milling Titanium
« Reply #9 on: June 12, 2011, 06:40:18 PM »
You will have to pull harder than that  :D :D :D :D :D

Offline DaveH

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Re: Milling Titanium
« Reply #10 on: June 12, 2011, 06:47:51 PM »
Doubleboost,
You will have to pull harder than that  :D :D :D :D :D

Wouldn't dream of it :) :)

A titanium exhaust - wow that's posh :thumbup:

 :beer:

DaveH
(Ex Leicester, Thurmaston, Ashby De La Zouch.)

Offline doubleboost

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Re: Milling Titanium
« Reply #11 on: June 12, 2011, 06:51:32 PM »
I will have a word with them they use titanium all the time
They also use inconell (talk about witches tits) that stuff is seriously tough
John

Offline DaveH

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Re: Milling Titanium
« Reply #12 on: June 12, 2011, 07:06:52 PM »
John,

I can turn it seemingly with little difficultly - using HSS tool - I keep it sharp.

Now milling it just becomes a disaster.  :bang:

I want to mill it with a 1mm dia mill or an engraving cutter just .003" deep - seems carbide is the way to go. With some cutting fluid in a "puddle" around it.

I know it is quite small.
And maybe the spindle speed was too high, I'm not sure. Maybe it was too slow.
So should I use a slow spindle speed -say 200rpm?

Thanks

DaveH
(Ex Leicester, Thurmaston, Ashby De La Zouch.)

Offline DaveH

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Re: Milling Titanium
« Reply #13 on: June 12, 2011, 07:11:56 PM »
Tim,
I have also used a carbide V-point for engraving using extremely shallow cuts, with a little bath of thin cutting oil.
Tim

"extremely shallow cuts"  - .001" slightly deeper or shallower.

Any idea of the spindle speed for the engraving cutter.

Thanks

DaveH
(Ex Leicester, Thurmaston, Ashby De La Zouch.)

Offline doubleboost

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Re: Milling Titanium
« Reply #14 on: June 12, 2011, 07:16:46 PM »
Personally i would run it fast 1000 plus
I will ask my friend who machines it all the time  :D :D :D :D
John

Offline DaveH

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Re: Milling Titanium
« Reply #15 on: June 12, 2011, 07:21:23 PM »
John,

Thank -you that's nice of you.

Ask your friend if he runs the spindle faster or slower than he does for steel.

 :beer:

DaveH
(Ex Leicester, Thurmaston, Ashby De La Zouch.)

Offline doubleboost

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Re: Milling Titanium
« Reply #16 on: June 12, 2011, 07:27:06 PM »
No problem
He made a con rod for a racing ic (glow plug ) engine on a big cnc machine out of titanium .
Just to get some time in with the machine .
It really was a work of art , i will try to get some pictures from him
As well as feed and speed rates
John

Offline spuddevans

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Re: Milling Titanium
« Reply #17 on: June 13, 2011, 02:05:19 AM »
Tim,
I have also used a carbide V-point for engraving using extremely shallow cuts, with a little bath of thin cutting oil.
Tim

"extremely shallow cuts"  - .001" slightly deeper or shallower.

Any idea of the spindle speed for the engraving cutter.

Thanks


DaveH
I ran it at my mill's max (X2 with belt conversion) which I think is about 2500-3000rpm. DOC was 0.01mm-0.02mm for the engraving or I was breaking cutter tips (but I was using quite fragile and slender cutters). When I was actually milling (as opposed to engraving) I was using a 2mm end mill and ran it at about 2000rpm and 0.05mm DOC.

When engraving I found that the titanium would leave a very slight raised burr around the edge of the engraved portion, but a few wipes over with some wet and dry 800grit on a flat surface would take care of that.

 :offtopic: This is what I did





I broke a cutter after doing the "L", well actually several cutters, until I got the DOC's and feed's sorted.


Tim
Measure with a micrometer, mark with chalk, cut with an axe  -  MI0TME

Offline DaveH

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Re: Milling Titanium
« Reply #18 on: June 13, 2011, 07:34:17 AM »
Tim,
Thank you Tim,

Looks a million times better than my feeble attemps.

Mmmmm I think my spindle speed 200 - 1000rmp was too slow used the same DOC. For some reason I had it fixed in my head not to go above 1000rmp. :doh:

I think I'm going to give my brain cells a jolly good talking too :lol: :lol: :lol:

Thanks
 :beer:
DaveH
(Ex Leicester, Thurmaston, Ashby De La Zouch.)

Offline spuddevans

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Re: Milling Titanium
« Reply #19 on: June 13, 2011, 09:10:54 AM »
I forgot to say that the engraving on that ring took about 5-6 passes at 0.01-0.02mm DOC's.

Tim
Measure with a micrometer, mark with chalk, cut with an axe  -  MI0TME

Offline DaveH

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Re: Milling Titanium
« Reply #20 on: June 13, 2011, 09:22:15 AM »
Tim,
Thank you - Later this week I'm going to give it another try.
 :beer:
DaveH


(Ex Leicester, Thurmaston, Ashby De La Zouch.)

Offline jim

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Re: Milling Titanium
« Reply #21 on: June 13, 2011, 01:17:18 PM »
i've machined a lot at work, slow and steady is the way. sharp tools and time work best
if i'd thought it through, i'd have never tried it

Offline DaveH

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Re: Milling Titanium
« Reply #22 on: June 13, 2011, 01:22:06 PM »
Jim,

Thanks,
If I may - what tools do you use HSS /  Carbide

With respect to steel do you use a faster or slower spindle speed?

 :beer:
DaveH
(Ex Leicester, Thurmaston, Ashby De La Zouch.)

Offline mgj

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Re: Milling Titanium
« Reply #23 on: June 15, 2011, 04:24:36 AM »
I used to do some bits for racing cars - until I found how notch sensitive and gall sensitive it is. Horrible stuff and actually potentially very dangerous if one is not certain of what one is doing - in stressed or critical applications.

The trick I always found when taking small cuts is the feed rate. It does worrk harden easily, so whilst speeds were never an issure for me (a one off maker not a maufacturer) I found one had to stop it rubbing in any shape or form.  Been a while now, - thank heavens, but a relativley high feed was always a lot more imortant than speed - and if possible, don't take small fine cuts!

If it is a stressed application, its important (as in VITAL) to radius all corners, and if screw cutting to use a radiused tip.

Offline bp

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Re: Milling Titanium
« Reply #24 on: June 17, 2011, 01:27:14 AM »
Totally agree with mgj.  Where I used to work they were looking into machining some high end Ti, the torque required was off the scale, with machine, cutter, and set up rigidity being absolutely vital.
cheers
bp