Chem milling is a subtractive manufacturing process that involves the use of chemicals to remove material from a workpiece. The process starts with a maskant, a chemical-resistant material that is applied to the surface of the workpiece to protect certain areas from being etched. The workpiece is then submerged in a bath of chemical etchant, which selectively dissolves the exposed material, leaving behind the desired shape.
There are several types of chem milling processes, including isotropic etching, which removes material uniformly in all directions, and anisotropic etching, which removes material in a specific direction. Isotropic etching is commonly used for thinning and shaping parts, while anisotropic etching is used for creating precise features with vertical sidewalls.
Chem milling can be used on a variety of materials, including metals, plastics, and composites. The process is ideal for producing parts with complex geometries that are difficult or impossible to achieve with traditional machining methods. Chem milling can also be used to remove surface defects, such as burrs, scratches, and oxide layers, leading to improved surface finish and dimensional accuracy.
Advantages of chem milling