Plasma cutting Titanium?

[James Spurgeon]

I have seen a lot of conflicting information on the internet regarding cutting Titanium with a standard plasma cutter.

Some people warn the Ti can ignite if standard air is used when plasma cutting.

Others state that using a mixed inert/hydrogen gas for plasma cutting Ti is beneficial, but that cutting with standard air will cause no problems as long as the heat affected zone is ground to remove oxides potentially formed during cutting...

 

I do know that Ti is technically flammable, but I am not sure which way to trust...

 

Has anyone on here had any experience with flame or plasma cutting Ti?

Thanks,

James

[Richard Furrer]

It cuts OK with plasma, but the arc is very bright. The droplets will light anything around on fire.

You need to up your shade protection and keep all flammables away.

 

Industrial shops use oxy torches.

 

As to damage done..well sure...O2 and the HAZ and bad cut edges need to be dealt with, but you can make one part into two.

 

A carbide bandsaw works well.

Ric

[Bret]

Never cut it with a plasma torch but I have cut Ti 6Al-4V with a laser using Nitrogen. In my experience it's flammability is increased the thinner it gets. I've set mill chips on fire, but nothing over about .002 thick. You shouldn't have a problem with the piece itself but you would probably be shooting flaming material out the backside instead of molten splatters, or flaming molten splatters at any rate.

 

Oh good timing Ric ^^^ what he said

Edited November 4, 2014 by Bret

[James Spurgeon]

OK, great info guys, thanks! I generally wear an auto darkening welding mask set on shade 9 or 10 for complicated plasma cuts where I need to watch the jet directly, so I will make sure to set it a bit higher for the Ti.

A couple more specifics just in case that changes your advice.

I am intending to cut some semi-complicated liners out of 0.035" (roughly 1/32) Grade 2 (99% Ti) sheet, as the smallest unit of sheet I can find is 6" x 6".

The complications are mostly external profiling, not window cuts, so can be cleaned up with ceramic belts and a small wheel on my KMG, which I hope will make dealing with HAZ a bit easier.

I don't currently have a band saw, carbide or otherwise, or even an angle grinder with cut off disks. My cutting tools hop from tin snips and hack saw to hot cut hardy and then jump to the 220V plasma torch... I kind of skipped the intermediate options thus far in my equipment purchasing.

So, does any of that info change the scenario for plasma cutting?

If it still looks safe to proceed, and assuming I keep the torch moving "Beep, Beep"; what is a good margin to leave for post plasma grinding to eliminate the HAZ?

 

Thanks again for the input!

James

[Brian Dougherty]

James, I just sent you a PM about cutting these on a waterjet. Happy to do it as a favor if you are interested.

Edited November 5, 2014 by Brian Dougherty