The US Coast Guard was quite fed up with the old tank engines, the Lycoming LTS 101, that they had in their Dauphins, and made a stink, sending the manufacturers back to the drawing board, and voila, the ceramic blade was the result.
Actually I'm not sure if its a Lycoming invention, but it is a mod they've been offering for the LTS101 for quite a few years now, at least on the 222 and Dauphin, and it certainly reduces the maintenance on those engines, but at quite a cost.