This disclosure relates generally to finishing a component surface and, more particularly, to finishing techniques that immerse at least a portion of the component in a fluid.
Many components include surfaces that are finished prior to use. The surfaces of both used components and newly manufacturing components may be finished. As an example, the surfaces of a high pressure compressor blade may be polished prior to use within a turbomachine. Polishing is one type of finishing. Turbomachine components often require relatively low surface finishing, such as an average surface roughness (Ra) of 1 to 5 micro-inch (0.0254 to 0.127 microns) Ra.
Electrochemical machining (or ECM) is an example finishing process that immerses at least a portion of a component in a fluid. Electrochemical machining processes use electrical energy to remove material. An ECM process creates an electrolytic cell in an electrolyte medium. A tool serves as a cathode, and the component serves as an anode. During the process, the ECM tool is positioned very close to the workpiece and a low voltage, high amperage DC current is passed between the two via an electrolyte. A high-amperage, low-voltage current is then applied to dissolve and remove metal from the component.
Electrochemical deburring is a type of electrochemical machining designed to remove burrs and impart small radii to corners. The process normally uses a specially shaped electrode to carefully control the process to a specific area. Unlike many other machining methods, workpiece hardness is not a significant factor in ECM, making ECM suitable for difficult-to-machine materials.
The electrochemical machining process can produce byproducts, such as salt, at the surface of the component being finished. The salt inhibits the finishing.