is it really that bad? I know there is research in 3d printed ceramics for engineering purposes. I thought maybe kinda you could get something pretty close since people are 3d printing em
Some seem to have extreme difficulty, like boron carbide (i think) but I thought maybe there is some approachable ones.
Yes, it is that bad, but it depends on what you are doing.
Pottery cycles are rated by
cones, a cone being a triangular molded shape, which slumps and falls over at a well defined time*temperature, made with a precision formulation.
A cone is not a specific temperature. It takes time for the components to react and dissolve, and the viscous part-glassy mix formed takes time to slump as well. This makes designing a thermal profile not the easiest thing, but it also means the body being fired will respond in the same way as the cone does.
If you're doing simple stoneware, you can usually fire over a wide range of levels. A cone 0 "bisque" firing is enough to stick the material together (it is hard and makes a "tink" sound when struck), but it isn't very strong and has a chalky feel. Cone 10 is very typical for a dense, strong body, or maybe cone 6 with a lot of flux in the mix. Pure clays typically melt around cone 30 (a peak temperature over 1800C I think).
The mix matters very much. Porcelain achieves its fine translucent beauty thanks to a large glass content. It must be fired very carefully, so that some crystalline matrix remains at peak temperature. A little more and it slumps to a blob. Too low and it's just any stoneware, with remaining porosity.
For electrical applications, you'd be most interested in porcelain and glazed stoneware for insulators, plain for spacers, and also steatite and cordierite for lower expansion applications (commonly used in wirewound resistors). Mullite and alumina are a bit more challenging (high firing temperature), and probably not very necessary outside of very high temperature applications (good for making your own kiln hardware, though).
Shrinkage on firing will be typical for a given batch, assuming it's well mixed and de-aired. Warpage occurs if heating is too fast or uneven. Dry bodies can be carved by hand or machine, but they are very weak so you can't get too crazy with it. Moist (but not soft) mix can be pressed by hand, or dry mix in a press proper. Liquid suspension (slip) can be molded in a porous (usually plaster or concrete) mold, then the excess poured out, making hollow shapes.
Precision, adequate for making insulators, would be pretty easy with molding and carving. Precision say for flat heatsink insulator plates, don't count on it -- you'll need a grinder for that, most likely. Fired items can definitely be shaped, but carbide or preferably diamond tooling is required, with very slow feedrates and water cooling.
Tim