Method of forming hollow channels within a component

A method of forming a channel in an article, the method comprising the steps of:

• forming a substrate having a surface and a groove recessed in the surface;
• placing a solid member in the groove so as to partially fill the groove and leave a void therein, the solid member being formed of a material chosen from the group consisting of nickel-based and iron-based alloys;
• filling the void with a fill material so that the groove is completely filled, the fill material comprising a metallic powder;
• consolidating the solid member and the fill material so that the fill material forms a solid mass that is bonded to the substrate and so that the solid member and the solid mass form a fill surface that is substantially coplanar with the surface of the substrate;
• forming a layer on the fill surface and on the surface of the substrate using a physical vapor deposition technique;
• and then
• etching the solid member from the groove so as to form a channel in the substrate and beneath the layer, the solid mass remaining in the groove and forming a wall of the channel.

A method of forming a channel in an article, the method comprising the steps of:

• forming a substrate having a surface;
• forming a groove in the substrate to have an edge at the surface of the substrate, the edge projecting over the groove;
• placing a solid member in the groove so as to partially fill the groove and leave a void therein, the solid member being formed of a material chosen from the group consisting of nickel-based and iron-based alloys;
• filling the void with a fill material so that the groove is completely filled, the fill material comprising a metallic powder;
• consolidating the solid member and the fill material so that the solid member and the fill member form a fill surface that is substantially coplanar with the surface of the substrate;
• forming a layer on the fill surface and on the surface of the substrate using a physical vapor deposition technique;
• and then
• etching the solid member and the fill material from the groove so as to form a channel in the substrate and beneath the layer.