Spall resistant abradable turbine air seal

摘要

An abrasive coating (60) for a rotor shaft (50), the abrasive coating having a metal bond coat layer (62) on the rotor shaft and an abrasive layer (66) over the bond layer for contact with vanes (26) during operation of the rotor shaft. The abrasive coating includes a matrix containing a low strength filler having an increased concentration radially outward from the bond layer to the outer surface of the abrasive layer. The matrix may be ceramic or metal.