Patent ID: 7347663

Claim:
A method for performing abrasion resistant surface treatment on surfaces of fluid passages defined by a main plate, a side plate and vanes of a rotary member, comprising steps of: dividing the surface of the fluid passages into a plurality of areas determined based on radius from an axis of rotation of said rotary member; spraying an abrasion resistant material on a surface of the fluid passages in a radially outer-most area A 1 between an outer periphery of said rotary member and a circle C 1 with a desired radius R 1 , by a high speed flame spraying method; and spraying an abrasion resistant material including WC, Ni, Cr, Co and B on a surface of the fluid passages in a radially inner-most area A 3 inside a radially inward opening defined by a circle with a desired radius around an axis of said rotary member, by a spraying and fusing method.