CHEMICAL AND ELECTRO CHEMICAL ENERGY BASED PROCESSES

Chemical Machining

Chemical milling

Electrochemical Machining

Electrochemical Honing

Electrochemical Grinding

CHEMICAL MACHINING

Chemical machining (CM) is the controlled dissolution of work piece material (etching) by means of a strong chemical reagent (etchant). In CM material is removed from selected areas of work piece by immersing it in a chemical reagents or etchants; such as acids and alkaline solutions. Material is removed by microscopic electrochemical cell action, as occurs in corrosion or chemical dissolution of a metal. This controlled chemical dissolution will simultaneously etch all exposed surfaces even though the  penetration rates  of  the  material  removal may be  only 0.0025 –0.1 mm/min. The basic process takes many forms: chemical milling of pockets, contours, overall metal removal, chemical blanking for etching through thin sheets; photochemical machining (pcm) for etching  by  using  of  photosensitive  resists  in  microelectronics;  chemical  or  electrochemical polishing where weak chemical reagents are used (sometimes with remote electric assist) for polishing or deburring and chemical jet machining where a single chemically active jet is used. A schematic of chemical machining process is shown in Figure.

Figure. (a) Schematic of chemical machining process (b) Stages in producing a profiled cavity by chemical machining