Chemical machining process: Working, Diagram, Advantages, Applications

What is Chemical Machining (CHM)?

Chemical machining is a machining process in which material removal carried out with the help of chemicals. These chemicals react with work-piece material and dissolves it.

It is one of the non conventional machining process.

Continue reading to know about its working process, construction, advantages, etc.


The below figure gives the basis idea of chemical machining.

Chemical Machining

Chemical Machining setup consists of the following components.

1) Chemical :- The chemical used in this process is also called as etchant. This chemical is responsible for the removal of the material from the work-piece.

It chemically reacts with the desired portion of work-piece material & dissolve it.

The types of etchants used in machining depends on the material of work-piece.

2) Cooling & Heating Coil :- The Cooling & Heating coil is used to maintain desired temperature of the chemical or etchant during the process.

3) Stirrer :- The stirrer helps in the mixing of the chemical or etchant.

Chemical Machining Working:

The chemical machining is done in following processes or steps :-

1) Cleaning :- In this step, the work-piece is cleaned using solvent to removes the dust, oil contaminants from the work-piece. It is necessary to clean, as the masking will not be done properly due to dust or oil contaminants.

2) Masking :- Masking is the process of applying the maskant or cover on the cleaned work-piece surface. This maskant or cover does not react with chemical or etchant.

It protects the covered portion of work-piece surface from being dissolved.

3) Scribing :- In this process, the maskant is removed from the portions of work-piece surfaces which has to be machined. It is done before the immersing work-piece in the chemical or etchant.

4) Etching :- In this process, the workpiece is immersed in the chemical or etchant. The chemical reacts with the work-piece surface where maskant is not present & dissolves this portion of the work-piece.

5) De-masking :- After the etching process, the remaining applied maskant is removed.

Therefore, in such way, chemical machining works.

Advantages of Chemical Machining:

  1. It produces high precision metal parts.
  2. It can machine any shape & size.
  3. Machining of work-piece from all sides at the same time.
  4. Less skilled labors can handle process
  5. High surface finish
  6. High machining accuracy

 Disadvantages of Chemical Machining:

  1. Chemical solution used in this process is dangerous for human health.
  2. It is a slow process.

Applications of Chemical Machining:

  1. In drilling different sizes holes on plates.
  2. In machining of various automobiles parts.

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Pratik is a Graduated Mechanical engineer. He enjoys sharing the engineering knowledge learned by him with people.

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