>>712612132Depends what you mean by 'stuff.'
If you mean a flexible material like kevlar that is woven into ballistic vests, silicone carbide is used in level 3 civilian vests and some law enforcement vests, depending on location and severity.
Bear in mind, these are all level III options, meaning they can stop up to small-caiber rifle rounds, they do not protect against heavier rounds, like the AK-47. Which is exactly why the US military doesn't care for them, since everyone they'd be fighting uses an AK-47 or a variant of it nowadays. So, they use level IV options, which are plate-carriers.
As of yet, there is no real replacement for ceramic composite plates. Ceramics sandwiching hardened interior plates does wonders at stopping anything that isn't also designed specifically to pierce armor, and even then, they often win out.