Sounds like the future for hard, brittle machining. (WIP).

Generally speaking, when you think about material removal, you're probably thinking about cutting a softer material by applying a harder material to its surface. Which is pretty much the way that it has always been done--even before there were machines involved. There are, of course, some alternative processes, such as using electrical discharge machining or deploying a laser. But one process that should be taken into account, especially when the materials that need to be machined are comparatively brittle (and consequently likely to crack when using the tried-and true harder material on softer) is using sound--as in ultrasonic machining.

Lest you think that this is something that is being performed just in places like NASA labs, know that a certain high-performance German automotive manufacturer is deploying parts that have been ultrasonically processed--and these parts are (1) ceramic and (2) non-trivial. [We'd like to be less coy, but trust us: We'd tell you if we could. And know well that the application is impressive. OK. They're brake rotors. You'll have to guess the rest.]

Hermann Sauer GmbH [Stipshausen, Germany], which is part of the Gildemeister Group, is just launching a new ultrasonic series or machines [available in the US through DMG America] that's based on an ultrasonic spindle that vibrates a diamond tool at a rate of 20,000 times per second. The consequence of that is that it is able to remove small particles From the workpiece [which could be made of various ceramics, glass, silicone, graphite, etc.]--without physically touching the workpiece. So there aren't the mechanical or thermal stresses ordinarily associated with material removal. Not only is this process comparatively fast (said to be as much as five times more productive than comparable methods--e.g., it can remove aluminum oxide at a rate of 220 mm3/min.), but it is capable of providing surfaces of Ra < 0,2 [micro]m.

There are two machines: the DMS 35, which offers a work envelope of 350 x 240 x 340 mm, and the DMS 50, which has a 500 x 400 x 400-mm work envelope. Because the machines can be Fitted with a rotary table, five-sided machining can be performed in a single setup. Control algorithms have been developed so that unattended machining can be performed with the equipment.

Although this may not be run-of-the-mill technology-yet--who wants to make (or buy?) run-of-the-mill products?