Quote:
Originally Posted by techhelpbb
This is why there is no minimum desirable operating temperature specified.
This is also why it works for me.
I told both companies that I've used these with aluminum and no huge red alarms went off.
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I'm surprised that they said that - I've heard plenty of people having issues when they tried to run TiAlN in Aluminum and had issues with build up edge forming, surface smearing ruining the finish etc. Could have been your cut parameters being moderate enough that it wasn't noticable, or the cut was generating minimal heat (quite likely with a small 1/8" end mill). I guess best case you're paying a decent amount of $$ over uncoated without an appreciable benefit compared to other coatings.
Either way - the proof is in the products that they sell. Duramill and Niagara don't put that coating on their aluminum-specific end mills. They both sell either uncoated or TiCN coating on those tools. They're both a bit behind the curve on aluminum coatings it seems, since ZrN and TiB2 are being used in many other mfg's high end aluminum products. We've used the Niagara aluminum specific end mills with TiCN since McMaster sells them and it's convenient (AN3xx series). They work well, but I can't speak to if they're appreciable better than uncoated - we don't push our machines that hard and they're not being run 24/7 to notice any difference in longevity.
I have never seen anyone sell an aluminum specific end mill with TiAlN on it - uncoated, TiCN, ZrN, TiB2, and DLC are the only ones I can remember seeing. I've also never seen aluminum as a recommended material for TiAlN or AlTiN.
Quote:
Originally Posted by techhelpbb
However I still agree a slower spindle is desirable for this purpose.
It would eliminate the need for the tool that could be a bit more expensive.
Additionally it would reduce the risk that a slow cut would weld.
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It doesn't really matter - you want to run carbide with smaller cutters. For one, the price difference is usually minimal compared to HSS. Carbide is significantly more rigid that HSS, which is especially helpful for small diameter cutters. And even uncoated carbide has almost no speed limit in aluminum. Cuts weld if the SFPM is too high, chip load is too low, or the chips aren't being ejected from the cut. So to fix the first you use carbide, to fix the second you use a single flute cutter so you can maintain proper chip load at lower feeds, and that also fixes #3 by giving room for chips to eject.
If it's on a mill and not a router, then you still want to use carbide if only for the rigidity benefits.