machining tantalum!?

Hey all. Im running this job that has a peice of tantalum fused into a peice of brass. does anybody have any experiance with tantalum? what are you using for inserts and what make are they?

A little Googl'n turn up this:

Turning and Milling

In lathe operations, cemented carbide tools with high cutting speeds should be used. The tools should be kept sharp and ground with as much positive rake as the tool can withstand. The same rakes and angles used with copper will be satisfactory. A minimum speed of 100 surface feet per minute will work for most Turning operations. Slower speeds will cause the metal to tear. A proper lubricant should be used as a cutting medium and the work must be well flooded at all times. Basically the same procedures should be used when milling drilling taping or threading tantalum. Staggered tooth type milling cutters with substantial back and side relief are recommended. When dies or taps are being used, they should be kept free of chips and kept as clean as possible. When drilling, the point of the drill must be relieved so that it does not rub the material. Threading is best done on a lathe rather than a treading die.

Seems like a good candidate for PCD or ground uncoated carbide (Aluminum geometries)

i found the same thing when i googles it......i was hoping someone on here might have a little bit of experiance with this material....

I think this reply was posted in the wrong place.


Stuart
Forums Member
#5 | Posted: 3 Mar 2010 12:55
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I did some missile work years ago using some customer supplied Tantalum. It's expensive to make mistakes in. I used speeds and feeds that we typically use on titanium and light cuts and had no issues on the first couple projects. One of the later projects we were supplied with the material in an annealed state and it was miserable. It wanted to gall, tear, ick! It was like trying to machine lead again... of course part of the issue is when your customer either won't or can't tell you the specific properties of what you are trying to whittle on.

The only thing to bear in mind is that it work hardens. Copper machining would be a good example to campare it to, or maybe 304 stainless. You want to feed consistently, not aggresively, and to light a cut is worse than to heavy a cut.

I used mostly very sharp, uncoated carbide inserts in a positive grade. It wasn't that big a deal, other than worrying about the cost of scrapping the parts. If you are trying to drill small holes or grind it though, all I can say is Good Luck!