What is Non Traditional Machining Process (NTMP): Introduction, Need, Classification, Applications

  Non Traditional Machining Process 

     Introduction :

• Manufacturing processes can be widely divided into two groups and are primary manufacturing processes and secondary manufacturing processes.
• The elders provide a basic form and a size to the material according to the needs of the designer. Casting, forming the powder metallurgy are such processes to name a few. Secondary manufacturing processes provide the form and final size with stricter control over the dimension, surface characteristics, etc. Materials elimination processes are mainly secondary manufacturing processes.
• Material removal processes can still be divided into mainly two groups and are "conventional machining process" and "non-traditional manufacturing process". Examples of conventional machining processes rotate boredom, grinding, shaping, brochure, imitation machine, grinding, etc.
• As like, from abrasive jet machining (AJM), ultrasonic machining (USM), water jet machining, and abrasive water (WJM and AWJM). Electro-discharge machining (EDM) is one of the non-traditional machining processes (NTM).                                        

 What is the need for Non-Traditional Machining (NTM) Processes?

Conventional machining meets industry requirements for decades. But the new exotic work material and innovative geometric design products and components put a lot of pressure on the capacity of conventional machining processes to produce components with economically desired tolerance. This prompted the turn of events and development of the NTM interaction in the business as an effective and monetary option to the ordinary. With the development in the NTM process, currently, there are often first and not alternative choices for conventional processes for certain technical requirements.

The following are the examples where the Non-Traditional Machining process is preferred over the conventional machining processes.

• Complicated blind hole in shape eg Square hole 15 mm x 15 mm with a depth of 30 mm.
• It is difficult for machine material - for example, the same example above in Inconel, ti-alloys, or carbide.
• Low-stress electrochemical milling is preferred compared to conventional milling.
• Inner hole with small hole diameter-e.g. 1 hole 1.5 mm with 1 / D -20.

Classification of NTM Processes:-  

                            Always carried out depending on the nature of the energy used for the elimination 

 Mechanical Processes: 

                          Erosion of the working material by a high flow stream of abrasives or fluids (or both)

• Electro-Chemical Processes: This is the metal removing process where the electric charge and chemical reaction take place simultaneously. Usually used for mass production and used to work very hard materials or materials, namely difficult machines using conventional methods. It is only used for electrically conductive materials.   

Electro-Chemical Machining (ECM) 

Fig. Electro-Chemical Machining

• Electro-Thermal Processes: Thermal energy is applied to a very small part of the work surface, causing the portion to be removed with fusion and/or evaporation of thermal energy materials produced by electrical energy conversion.

Electro-discharge machining (EDM)
LaserJet Machining (LJM) 
Electron Beam Machining (EBM)

Fig.Electro-Thermal Processes

Chemical Processes:

 Most materials (metals particularly) are susceptible to chemical attack by certain acids or other etchants. In chemical machining, Chemicals selectively eliminate the material from the parts of the work part, while other parts of the surface are protected by a mask.

Chemical Milling (CHM)
Photochemical Milling (PCM) etc.

Fig. Chemical Process

Application of NTM Processes:-

• Technologically advanced industries like aerospace nuclear power, wafer fabrication, automobiles has eve increasing use of High strength temperature resistant (HSTR) alloys and other difficult to machine materials like titanium, SST, tungsten, molybdenum columbium, ceramics, and semiconductors. It is no longer possible to use the classic process for machines at these alloys.
• Production and processing parts of complicated shapes in HSTR and other hard to machine alloys) is difficult time consuming and uneconomical by conventional methods of machining.
• Innovative geometric design of products and components made of new exotic materials with desired tolerance surface finish cannot be produced economically b conventional machining.

The following applications are provided where NTM processes are preferred over the conventional machining process :

• Intricate-shaped blind hole - e.g. square hole of 15 mm x 15 mm with a depth of 30 mm with a tolerance of 100 microns.
• Difficult to machine material - e.g. Titanium alloys or carbides, austenitic nickel-chromium-based superalloys,  High Strength and Temperature Resistant (HSTR) alloys, Ceramics, composites, satellites, etc.
• Low-Stress Grinding - Electrochemical Grinding
• Deep hole with small hole diameter-e.g. 11.4mm hole with 1/d - 20. 
• Machining of composites.