In accord with a preferred mode of the present invention, the leading edge of each blade is armored by means of a string of separately fabricated inserts or implants such as are shown at 24 in the drawing herewith; such implants being molded of a ceramic material selected from the class including ??-SiC, ??-SiC and ??-Si3 N4, and may or may not include reenforcing and toughening additions such as