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EXOTICS

Posted: Sun Jun 16, 2013 3:51 pm
by nathan
Like I said in my intro, I am pretty new to welding.

Other than magnesium, what are exotic metals?
What are they used for?
Why am I so attracted to the idea of welding magnesium? (kaboom)
How are they welded?
Anybody have experience in the complications of welding exotics? (other than spontaneous combustion)

Re: EXOTICS

Posted: Sun Jun 16, 2013 4:54 pm
by Otto Nobedder
Magnesium isn't what I had in mind when thinking of "exotic" metals. That's cheap casting metal.

I was thinking more like Titanium and Tantalum...

Steve S

Re: EXOTICS

Posted: Sun Jun 16, 2013 5:17 pm
by nathan
how do you weld titanium?

Re: EXOTICS

Posted: Sun Jun 16, 2013 5:20 pm
by Otto Nobedder
I've never done it.

I think Jody has a video on it.

Steve S

Re: EXOTICS

Posted: Mon Jun 17, 2013 10:19 pm
by Vince51
Titanium is a funny metal. It's VERY sensitive to the atmosphere. So interpass temps really come in to play. I only have experience with titanium pipe. Purge meters, trailing shields, high freq, post flow a must. I assume most small parts are welded on a purge block. It makes a nice puddle tho. If you add filler anywhere but the puddles leading edge it will stick and almost impossible to melt it off. Several different grades of the stuff. To expensive for me to play with so I'm not proficient with it. Nickel and chrome alloys are common in my field of work. Just my opinion of all the alloys high carbon steel is the most difficult to fool with. It all makes a puddle tho.

Vince

Re: EXOTICS

Posted: Mon Jun 17, 2013 11:10 pm
by TamJeff
I remember when inconel used to be considered exotic.

Re: EXOTICS

Posted: Tue Jun 18, 2013 7:08 am
by Alexa

Re: EXOTICS

Posted: Tue Jun 18, 2013 10:02 am
by BDoubleU
nathan wrote:Like I said in my intro, I am pretty new to welding.

Other than magnesium, what are exotic metals?
What are they used for?
Why am I so attracted to the idea of welding magnesium? (kaboom)
How are they welded?
Anybody have experience in the complications of welding exotics? (other than spontaneous combustion)
Good questions. I've always referred to exotics as metals other than your everyday steels, stainless steels & aluminums. Basically, they are metals used in special applications because they have special properties & are typically expensive, even requiring special welding practices.

Magnesium can be a cheap casting material ... But this metal is often used for complex castings in the aircraft industry. Very expensive & specialized ... And yes, the dust can ignite so special considerations are required. Many people mistakenly refer to Zinc die cast alloys (pot-metal) as magnesium ... And although there may be mag in the casting ... It's not high-grade.

When you ask about others - titanium comes to mind as the most exotic metal ... For a number of reasons. It's expensive, you don't see it everyday & it's got some unique properties. But, don't overlook other exotics as well:

- steels: high strength low alloy steels, nickel & copper alloys can be considered exotic
- stainless: super duplex & high carbon stainless is pretty sensitive stuff to weld
- aluminum: alloys like 2219 are considered un-weldable without special techniques
- precious metals like gold, silver, platinum & palladium fit the classification for obvious reasons

Each of these exotics is included for various reasons ... And each has special welding considerations. It's also worth noting that some alloys on this list are not considered exotic in the industries they are used in. For example, titanium isn't exotic for someone in the aircraft industry ... They weld it everyday. And anodized aluminum isn't exotic for someone in the marine industry either ... And Inconel is used commonly in piping applications. However, unless you're in those trades - you may not ever be exposed to some of these unique metals.

Re: EXOTICS

Posted: Tue Jun 18, 2013 1:55 pm
by WerkSpace
Just when you thought that Titanium was an exotic metal, there's a whole new breed of metals coming down the pipeline.
http://www.redorbit.com/news/science/16 ... omposites/
http://www.youtube.com/watch?v=C-IYQntl9C0

Aluminum foam has found its usefulness.
https://www.youtube.com/watch?v=Cmcvh7TrdUk

3D printing is a recent technology that is going viral.
https://www.youtube.com/watch?v=hawFu-iAa_Y
https://www.youtube.com/watch?v=pQHnMj6dxj4

Re: EXOTICS

Posted: Fri Jun 21, 2013 4:19 am
by TamJeff
I would have to say that random cast aluminum is the most exotic of the common alloys. Why? Because nobody in their right mind really wants to make a living at welding it, or considered a specialist in it. It's one of those materials that includes a certain "pucker" factor just looking at it and knowing it's about to become part of your day.

What really makes random cast exotic? What you are asked to weld will tend to be the only part of it's kind left in existence.

Re: EXOTICS

Posted: Fri Jun 21, 2013 5:57 pm
by Otto Nobedder
TamJeff wrote:...What really makes random cast exotic? What you are asked to weld will tend to be the only part of it's kind left in existence.
As in, "It's the last existing Widget that fits an 1874 Fruegenhaufer, and it's irreplaceable. I have no idea what it's made of.

Can you fix it?"

:lol:

Re: EXOTICS

Posted: Sat Jun 22, 2013 1:34 am
by TamJeff
Otto Nobedder wrote:
TamJeff wrote:...What really makes random cast exotic? What you are asked to weld will tend to be the only part of it's kind left in existence.
As in, "It's the last existing Widget that fits an 1874 Fruegenhaufer, and it's irreplaceable. I have no idea what it's made of.

Can you fix it?"

:lol:
Yep!

So much emphasis has been put on "exotic", that the common every day welding has taken a back seat.

I used to think about welding scientific stuff when I first got into welding school and I have been able to dabble in it over the years with TIG, but the thing that impresses me most these days is, someone who is a wizard with 6010 and 7018 stick. I wish I had enough time to get 'that' good at it.