Patent ID: 8609196

Claim:
A method for imparting wear- and corrosion-resistance to a metal substrate and forming a coated substrate, the method comprising: applying a first metal coating layer having a thickness between about 5 and about 50 microns to the substrate by a first thermal spray process depositing a first-layer composite carbide material comprising a first-layer carbide material and first-layer Co-based or Ni-based binder material to provide a bond layer over the metal substrate, wherein the first-layer composite carbide material comprises between about 75 and about 88 wt % first-layer carbide material and between about 12 and about 25 wt % first-layer Co-based or Ni-based binder material; applying a second metal coating layer over the first metal coating layer by a second thermal spray process depositing a second-layer coating material which is a Co-based material having at least about 60 wt % Co, to provide a support layer over the bond layer; applying a surface metal coating layer over the second metal coating layer by a third thermal spray process depositing a third-layer composite carbide material comprising a third-layer carbide material and third-layer Co-based or Ni-based binder material to impart wear- and corrosion-resistance to the outer surface of the coated substrate.