Machining Muscovite Mica

Hello, is anyone out there machining this material? I have been struggling with it for some time now. I am getting orders complete and good parts however it is killing my tooling. coolant is not an option.

The material is a laminated sheet .125", .25" .375: thick so downcutting tools are a must. Standard carrbide endmills burn up quickly no matte the speed or feeds. I have tried several coatings with limited success.

on todays job, im running 11000 rpm with a 40IPM feed , .063" DOC, 3/32" diameter 2 flute solid carbide, downcut endmill

I belive PCD or PVD diamonds are going to be my answer but I have yet to find anyone offering them in small diamters with downcut geometry??

thanks in advance for any help

Can you use air cooling?

Steve

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Originally Posted by steve323

Can you use air cooling?

Steve

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yes, i am using air to an extent. the abrasiveness of the material is just killing the carbide

Is this regular mica sheet or some kind of composite? I agree that you need diamond tooling, but a straight abrasive cutter might work as well as well as one with fluted geometry, since I doubt this stuff will form chips like metal does. I'd be inclined to use water cooling as well, to flush away the dust and keep things cool. But this company has diamond-coated downcut bits: https://www.secotools.com/#article/m_7802