Non-Conventional Machining Processes

Before starting our actual discussion about non-conventional machining processes let us see few problems that we encounter in conventional machining process: 

1.      Drilling a hole in a glass plate. (Which material to use as drill?)

2.      Drilling a long narrow hole, let us say of 1m-length and 0.01mm diameter.

3.      Machining or shaping a very hard material like ceramics or carbide.

 Non-conventional manufacturing processes are so called because they don't use traditional tools and methods for shaping of materials. All pf these methods make use of a form of energy which can be mechanical, electric, thermoelectric, chemical etc. 

The emergence of advanced difficult- to-machine materials (tough super alloys, ceramics and composites), stringent design requirements (high precision, complex shapes and high surface quality) and high machining cost are some of the problems being faced by the manufacturing industry. 

Advanced materials play role is modern manufacturing industries, especially in aircraft, automobile, tool, die and mould making industries. The greatly improved thermal, chemical and mechanical properties of the material (improved strength, heat resistance, wear resistance and corrosion resistance) have yielded enormous economic benefits to the manufacturing industries through improved product performance and product design. Traditional machining processes are not so efficient and able to machine the materials economically. This is because the traditional machining is most often based on removing the material using tools harder than the work piece. Polycrystalline diamond is an example of a hard material, which cannot be efficiently machine by traditional processes.  One of the most commonly used traditional processes for polycrystalline diamond machining is grinding but the grinding wheel wear rate in the case is 50 to 200 times higher than the wear rate of normal materials.  Similar is the difficulty in machining ceramics and composites.

So, to list, following factors had boosted the development of non-conventional machining processes: 

a)      New Materials With Low Machinability

b)      Dimensional Accuracy Requirements

c)      Higher Production Rate & Economy 

Classification of non- conventional processes:

Non-conventional process, a method to remove the material from a given work piece without using the conventional sharp edged tools like turning tool, drill bits etc.   Some form of energy, mechanical, electrical, chemical etc is used to remove material. These processes can be classified into various groups according to type of energy they employ namely:

1. Mechanical
2. Chemical
3. Electrochemical
4. Thermoelectric