US Patent 7094987 Hollow thermal spray electrode wire having multiple layers

An electrode wire for use in a thermal spray process. The electrode wire is formed with a first layer of a first material formed as tubular outer layer and a second layer of a second material, different from the first material, formed as a tubular inner layer located inside the tubular outer layer. The tubular inner layer includes in an outer surface which is located in substantially uniform contact at an interface with an inner surface of the tubular outer layer. The interface between the inner and outer layers is defined by a mechanical bond between the materials of the inner and outer layers. In a method of performing a thermal spray process the electrode wire is caused to vaporize and spray on a substrate surface to form a bondcoat on the substrate surface.