Snapped a 3/8 end mill on a titanium part last Tuesday

Was roughing out a medical implant and the tool caught on a recut chip, sent the whole thing flying, has anyone dealt with chip recutting in titanium without using high pressure coolant?

2 comments

2 Comments

kelly.dylan22d ago

...and that's why I stopped using TiALN coated end mills on titanium altogether. Switched to AlTiN a few years back and it handles the heat way better when you're dry cutting. My coworker still swears by the TiALN stuff though, says I'm crazy. But I've seen too many brittle fractures from thermal shock when the chip recuts and suddenly the tool temp spikes. Last time it happened to me was on a hip stem, the end mill just exploded like a firecracker. Had to spend an hour picking shrapnel out of the vise jaws.

lily23022d ago

That bit about the end mill "exploding like a firecracker" really got me... I always figured TiALN was the gold standard for anything with titanium in the name. Never even considered AlTiN for cutting, always thought it was just a decorative coating honestly. But hearing about thermal shock on a hip stem job, that's the exact kind of nightmare that makes you question everything. Might have to try a few AlTiN roughers on my next stainless job and see if it handles the heat better than I think...