US Patent 7836593 Cold spray method for producing gas turbine blade tip

A quantity of particles (28) may be cold-sprayed toward the distal surface (22) of a turbine blade (6) at a temperature below a melting point of the particles at a velocity sufficiently high to cause at least a portion of the particles to adhere to the surface to form squealer ridge (24) with a desired cutting profile. The cutting profile may be defined by a face (52) and a land (54) disposed at a relief angle (38) relative to a direction of motion (58) of a cutting edge (48). The ridge may be built by multiple passes of a cold spray gun depositing sequential layers (30, 32, 34) of varying widths. An in-service blade having worn distal surface may be repaired using this technique.