Cutters for Nitinol?

[Matthew Hajicek - Singularity]

What's the best kind of cutter and coating for milling Nitinol?

[Pilot Plant Supervisor]

Nasty stuff. We have found that sharp tools with high shear work best. Insert cutters are iffy, as there is usually too much edge prep and not enough geometry. I played around with drilling, and had some success with Guhring 3 and 4 margin drills, but tool life was pretty short. Surprisingly, gundrilling went well. I managed to drill 2mm holes 8" deep in some test billets.

[Matthew Hajicek - Singularity]

So solid carbide endmills with a sharp edge like those for aluminum?  Do you use any coating or bare carbide?  Wow, that's some impressive drilling!

[Pilot Plant Supervisor]

We generally use solid carbide such as Data Flute medium helix. I haven't really found any coating working better than another because tool life is so poor. The company I work for actually makes the NiTi alloys, and most of the machining we do is for R&D. I have never had to make production parts with it, so I haven't ran enough quantity of anything to dial in cutters and coatings.

[Matthew Hajicek - Singularity]

Thanks