Need Help!- Machining alluminium

[Rickylee53]

Hello,

I'm having problems with my end mills getting "clogged" on alluminium then the finish is poor.

I'm using a 3mm 4 flute carbide end mill at 3500rpm's. Using a feed rate of 60mm per minute, taking a 0.5mm cut with flood coolant.

The cutters were from here, i'm not sure if you can get an alluminium specific which is less likely to clog, or change the feed/speed

7LEADERS 2MM SOLID CARBIDE END MILL (E114F) TiALN NEW | eBay

Any suggestions?

[WATERJET71]

use a 2 flut endmill

[Rickylee53]

Originally Posted by WATERJET71 use a 2 flut endmill

Will try that, is there any way to make my current cutters work? I've got lots of 4 flute end mills.

[dblox]

Three problems, the cutters are coated (uncoated would be much better for aluminium), too many flutes, and the feedrate is not high enough.
Try upping the feedrate to about 250mm / min.
At 60mm / min a four flute cutter is kind of friction welding its way through aluminium.
You need to make a big enough chip with each flute so that the coated cutter can actually take a scoop of metal away instead of rubbing, but not so big that the chip jams up in the flute.

[Rickylee53]

Originally Posted by dblox Three problems, the cutters are coated (uncoated would be much better for aluminium), too many flutes, and the feedrate is not high enough. Try upping the feedrate to about 250mm / min. At 60mm / min a four flute cutter is kind of friction welding its way through aluminium. You need to make a big enough chip with each flute so that the coated cutter can actually take a scoop of metal away instead of rubbing, but not so big that the chip jams up in the flute.

Hello,

Thanks for your reply.

Thats interesting to know about coated, i'll try and save these cutters for steel then.

I didn't realise you could go "too slow" I didn't dare go that fast for fear of snapping the tool or wearing it out very quickly.

While i'll probably reserve these cutters for steel i'll also try a faster speed rate on the next ones.

Thanks again for your help.

[Geof]

TiAlN coated tools have a coating that is partly aluminum oxide, that is the Al part of the name. Using these cutters for aluminum is not successful because the aluminum oxide coating tends to stick to aluminum not allow the chip to slide past. Not even flood coolant can overcome this stickiness and if you try using these cutters on aluminum at high rpms on a big machine you get a smoking, steaming blob of metal spinning round.