Niobium anyone?

hesstool · Oct 12, 2007

I have a fun filled weekend approaching. First up I get to machine my all time favorite, pure Tungsten. Next up will be Niobium. (Both are turning applications) I’ve never touched this Niobium stuff so this will be pretty interesting since my customer told me it was “VERY” expensive.

I found some guidelines online for machining Niobium, but I want to hear about some “real world” experiences with it.

jim rozen · Oct 12, 2007

Tough, gooey. Sort of like OFHC copper on
steroids. Not real abrasive. I've used
dead sharp HSS tooling for it in the past.

Jim

bikebuilder · Oct 12, 2007

Isn't it Ti like? A couple Niobium bike frames came out last year.

bb

hesstool · Oct 12, 2007

Great... From one extreme to the other.

Bikebuilder, do you make custom road frames?

Keith Krome · Oct 12, 2007

My experience with Niobium is that it can seem soft, but it seems to work harden considerably. I don't recall ever turning it, Just milling and drilling it. I believe I used HSS tooling with no troubles, but I might have used carbide end mills(I know my drills were HSS). You have to really feed it to get under the work hardened surface. It doesn't like skim cuts. Also, I am not aware of the specific alloy I was working with. I believe it was commercially pure.

bikebuilder · Oct 12, 2007

hesstool, don't take my word.... never worked w/ it.
Yeah, I have done some road, but mostly mtn. and cross bikes.

bb

Metalcutter · Oct 12, 2007

We had better results Roll forming threads, as in roll tapping than thread cutting.

Stan-

Metalcutter · Oct 12, 2007

We had better results Roll forming threads, as in roll tapping than thread cutting.

Stan-

ren91131 · Oct 12, 2007

Nb's chemical relative ("father" actually) Tantalum is fairly simillar in properties. Ta is used a lot in high class heat exchangers, and I was able to find some info on turning it. I am making a Ta wedding ring and heard such bad stuff about turning it that I went with EDM. I also got some tungsten round bar for the ring. I asked around the greybeards at work; if you can get your hands on some 1% Lanthanum Tungsten alloy, it is much better to turn as it is far more ductile. They recomended 500rpm for 1" stock, PCBN inserts dry.

Travis

jim rozen · Oct 12, 2007

What's the application? Niobium/Titanium
alloy is commercially pretty common. I think
it machines better than pure Nb.

Jim

hesstool · Oct 12, 2007

It's Niobium C103 and is being used as a Filament Holder in an Electron Beam Gun.

I have to machine it down from .5" barstock to .248" dia. over a 2.5" length with ID threads on each end.

boslab · Oct 12, 2007

1%Lanthiated tungsten is used for tig electrodes,Nb 99.97 bal O2 grinds ok but never tried machining it still struggling with 97%W, brittle!
mark

split tenth · Oct 13, 2007

If its very expensive material you better clean out the chip pan and put some clean paper down because they will want every chip back.We did a platinum part and they wanted every molecule back.

Todd Stanley · Oct 13, 2007

It's just a smidge more expensive than titanium from what I've seen, I don't know what it's like to work though.

Billy Boy · Oct 14, 2007

Just spent a week cleaning Niobium residue out of an old sputter chamber (semi conductor manufacturing equipment) I was restoring. I didn't machine it per say, but it was real easy to scrap off with a paint scraper. Before I discovered the pain scraper I used scotch bright on it and it worked just fine except that it clogged up the scotch bright too fast. Real soft gooey stuff. I would imagine that you could cut it reasonably well with a piece of aluminum if you were so inclined. Softer than lead was my impression. This was pure Niobium. No alloy. I wasn't under the impression that it was particularly dear. Less valuable than silver I think.

Bill

claya · Oct 8, 2019

Any experience with turning Niobium C-103, and Pure tungsten?

Billtodd · Oct 9, 2019

will ask as per pm.

only pure tungsten work I've done was lapping a long thin mandrel down a few um to size - slow pita

claya · May 28, 2020

jim rozen said:
What's the application? Niobium/Titanium
alloy is commercially pretty common. I think
it machines better than pure Nb.

Jim

Jim,

You have any experience, or resources with sinker EDM of niobium? I suspect tantalum is a close comparison.

Also, your PM mailbox is full.

Sent from my SM-G975U using Tapatalk

ClappedOutBport · Mar 9, 2021

I have turned 3 pieces of spray formed niobium over the past few days. I actually found that my best surface finish came when my brazed carbide tool got very dull and a rounded off edge. Same when boring, the finish got progressively better as the tool got worse. The chip was a dull orange right at the toolbit running at 135 SFM and I got a very nice and smooth finish. When the tooling is fresh, it seems to leave gall lines all over the surface. I wasn't allowed to use an oil, I'm not sure if it would have helped. I polished with a finger sander and got a pretty good finish, though it wasn't required. Be careful on chamfers, it's grabby stuff. Soft, yet somehow brutal to tooling.

Also, I wasn't requested to save the chips, so I hope they aren't too expensive.

boslab · Mar 10, 2021

Implies negative rake?, 22.7 tons per cubic meter is all I remember
( was it tantalus daughter Niobe?)
Was called columbium in US
Mark

Niobium anyone?

Stainless

Diamond

Stainless

Stainless

Stainless

Stainless

Titanium

Titanium

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Diamond

Stainless

Titanium

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Plastic

Hot Rolled

Cast Iron

Titanium

Cast Iron

Cast Iron

Titanium

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