Hotter Than RBSiC, Tougher Than the Old Bricks: A Practical Guide to Nitride Bonded Silicon Carbide
Nitride bonded silicon carbide does not get the same attention as reaction bonded SiC or sintered SiC. That is fine. It is busy holding up kiln cars, lining aluminum cells, and taking abrasion that oxide-bonded brick cannot survive. I have spent enough time around NSiC — also written NBSiC or nitride-bonded SiC — to say this plainly: it is not a “budget version” of dense SiC. It is a different material with a different job.
The recipe is simple on paper. You take silicon carbide grain, add silicon metal, form the shape, then fire it in nitrogen. The silicon becomes silicon nitride and that nitride becomes the binder holding the SiC grains together. Typical bodies land around 70–80% SiC and 20–30% Si₃N₄. Shrinkage during nitriding is small, which is why you can make large plates, bricks, and awkward shapes without the warping drama of some other ceramics.