Cutting Titanium

nathan · Sat Apr 19, 2014 9:23 pm

So, I've decided to try and learn to weld titanium. Reading the AWS standard and it doesn't make any mention of cutting. This got me thinking about how it would be done if I were looking to cut some titanium on my back porch. As usual, I'm coming here before a google search.

Would it be possible to use a plasma cutter with argon instead of compressed air? I know that compressed argon is a lot higher pressure than the usual compressed air supply for a plasma, so I imagine it would need a regulator other than the one to the welder. Does this kind of thing exist? I would probably want to use something other than the standard quick-connect air hoses due to their propensity for leaks and titanium's affinity for any gas other than argon. Can the gas inlet on a plasma be changed from the quick-connect? Would I need to back purge the cut joint like a weld joint? or use a trailing shield? or would it be better to cut it in the same purge chamber that I'll be using to weld? Just some preliminary questions for my brainstorming stage. Opinions and advice are, as always, appreciated!!

Wes917 · Sat Apr 19, 2014 9:51 pm

If your just going to be practicing joints why wouldn't you use a horizontal band saw with coolant. That's how we cut ours. With the plasma cutter you'd be welding on a haz. What thickness are you thinking?

nathan · Sat Apr 19, 2014 10:14 pm

Wes917 wrote:If your just going to be practicing joints why wouldn't you use a horizontal band saw with coolant. That's how we cut ours. With the plasma cutter you'd be welding on a haz. What thickness are you thinking?

I'm not sure what thickness yet, maybe down to .020, if that's practical. I want to be fairly versatile, so I'd like to start thin. Won't the band saw impart some iron into the weld? I suppose you've got a point about the HAZ, that changes the crystalline structure of the material, doesn't it? didn't think of that one.

Superiorwelding · Sat Apr 19, 2014 10:44 pm

I would use a band saw if possible. Remember, even food grade SS in cut, sheared and formed on carbon blades/dies. You will never get away from this unless you spend a fortune on SS blades or dies/punches, if they exist. You can/should dedicate a blade to cutting Titanium, but for practicing you will be fine.
-Jonathan

Wes917 · Sun Apr 20, 2014 3:34 am

When I did my tests it was .030 and .080 and they were cut on a band saw and all was good. A other thing if you were to use a plasma cutter you would have to grind down the cut. This will embed containments in the piece as well.

nathan · Sun Apr 20, 2014 4:31 pm

Wes917 wrote:When I did my tests it was .030 and .080 and they were cut on a band saw and all was good. A other thing if you were to use a plasma cutter you would have to grind down the cut. This will embed containments in the piece as well.

What were the parameters on your test?

Wes917 · Sun Apr 20, 2014 5:03 pm

nathan wrote:
Wes917 wrote:When I did my tests it was .030 and .080 and they were cut on a band saw and all was good. A other thing if you were to use a plasma cutter you would have to grind down the cut. This will embed containments in the piece as well.
What were the parameters on your test?

Aws d17.1.

We had to cut them down as the plates we had would not fit our fixture.

Wes917 · Sun Apr 20, 2014 5:05 pm

Wes917 wrote:
nathan wrote:
Wes917 wrote:When I did my tests it was .030 and .080 and they were cut on a band saw and all was good. A other thing if you were to use a plasma cutter you would have to grind down the cut. This will embed containments in the piece as well.
What were the parameters on your test?

Aws d17.1.

We had to cut them down as the plates we had would not fit our fixture.

Thinking back I can't remember if we lined them up so we welded up the non cut edges or not. I don't think any special attention was paid or I'd remember it.

nathan · Sun Apr 20, 2014 6:46 pm

Does D17.1 specify anything other than titanium WPS's? I got G2.4 to start with as a general guide, but it doesn't have any WPS's.

P.S. Anyone have any WPS's for Titanium or Aluminum TIG they're willing to share? =)

Wes917 · Sun Apr 20, 2014 6:54 pm

D17.1 is aerospace all the played I did were tested to that standard inconel, aluminum, stainless, Haynes 188, and titanium. As far as the criteria I'm not sure the allowances as I wasn't in the lab, but their pretty tight.

nathan · Sun Apr 20, 2014 9:17 pm

Yeah, I looked up the book in the AWS bookstore. It's $120 for members, which is a bit much for me right now. Wish I had gotten it before my tax return was gone, but I guess it's something to save up for.