I have a design issue in my fusor that seems to require some machining of high alumina ceramics (no other material seems to work). Now, I have no troubles cutting tubing and rods with a diamond wheel, the ceramic PCB substrate stuff is a lot harder to do on the mill, but possible if you can hack rough edges (this app can't), and I've never managed to get a hole in that either, even with diamonds.
So, does anyone know how to machine this stuff to tiny sizes and get any yield at all? I've broken plenty in the attempts -- that last bit shatters when cutting with diamonds at even very low feed pressures and makes a mess, usually destroying the piece. And rats, no holes is a pretty large obstacle.
This is for making fusor grid parts, and nothing else insulating will live in or near a grid. Every other material is reduced by the hot H ions to metal and fails. Alumina makes a hydride that evaporates....so even this is sacrificial, but it's good while it lasts.