The Importance of Metal Finishing Processes in Aerospace

Metal finishing is a broad term that encompasses various processes used to modify the surface of manufactured items to enhance their aesthetic appeal, resist corrosion, improve electrical conductivity, reduce friction, or increase surface hardness.
Metal finishing in the aerospace and defense industry requires enhanced durability and corrosion resistance to withstand extreme environments. Key requirements include superior corrosion and wear resistance, thermal stability, electrical conductivity, and adherence to strict specifications like those in MIL-STD-171. Common processes to meet these needs are anodizing, various types of plating (like zinc-nickel), conversion coatings, and shot peening.
The techniques employed in metal finishing can be broadly categorized into chemical and mechanical. Chemical finishing processes involve altering the metal surface by adding, removing, or converting the surface layer through chemical reactions. Examples include chemical etching, electroplating, and anodizing. Mechanical finishing, on the other hand, involves physically altering the surface of the metal through processes like grinding, polishing, or blasting to achieve the desired finish.