Introduction to Non Traditional machining 2023-24
MODULE 1:
INTRODUCTION TO NON TRADITIONAL MACHINING
Introduction:
Machining is a process of removing excess material from the work piece material to obtain the
desired shape and size. Non-traditional machining processes, also known as unconventional
machining or advanced machining methods, offer innovative and highly specialised ways of
shaping, forming, or modifying materials. This makes it possible to work on challenging or
impossible materials to machine using traditional methods. Non-traditional machining
encompasses a diverse range of techniques, from electrical discharge machining (EDM) to
laser cutting, abrasive waterjet machining, and ultrasonic machining, each tailored to specific
applications and materials.
The process is classified into two types
1. Conventional or traditional machining
2. Non-conventional machining or Non traditional machining(NTM)
Conventional or Traditional machining make use of hard and sharp cutting tool to shape
materials .
Ex:Lathe,drilling machines,Grinding machines etc
Non conventional machining make use of various forms of energy sources relating to
light (lasers),sound(ultrasonic),magnetism,plasma ,electrical sparks ,chemical dissolution
etc
Need for Non Traditional machining:
1. Machining of hard workpiece materials like nimonics,carbides,stainless steel,heat
resisting steels and similar such materials involve high local stresses,friction and heat
generation during cutting.further high cost of tools and the damage generated in the
cutting tool/workpiece material duing machining made it practically or economically
impossible to machine such materials using conventional machining processes .
2. Machining of very small diameter holes,deep cavities,blind holes and complex
geometrical shapes are extremely difficult with conventional machining.this made the
need for NTM
3. Machining of workpiece materials which are too thin enough to withstand the high
cutting forces during conventional machining is another problem
4. Machining of Composite materials are difficult with conventional machining which led
to the need for NTM
5. Machining to a very surface finish with close dimensional accuracy of the product is
extremely difficult in conventional machining
Comparison between Traditional and Non Traditional machining
Department of Mechanical engineering,AIT Bangalore
Introduction to Non Traditional machining 2023-24
Traditional Non Traditional machining
1.The cutting tool must be harder than 1.cutting tool need not be harder than the
the work piece material work piece material
2.conventional machining involves 2.There is no physical contact between
direct contact between the tool and the the cutting tool and work piece
work piece
3.Tool life is less due to wear of the tool 3.Tool life is more comparatively
resulting from its direct contact with the
work piece material
4.Conventional processes use 4. NTM processes utilize different energy
mechanical energy for metal removal sources like mechanical, electrical,
chemical and thermal sources.
5.Machining is characterized by 5.Machining is mostly characterized by
macroscopic chip formation by shear microscopic chip formation .In some
deformation machining process like electrochemical
machining there is no chip formation
6.Difficult to obtain high accuracy and 6.NTM process result in high accuracy
surface finish and surface finish
7.Metal removal rate is limited by the 7. No such limitations.NTM process can
mechanical properties of the work piece remove material with much ease even
material with difficult to cut materials.
8.Conventional processes may require 8.Require skilled operator
skilled or unskilled operator
9.Low capital cost 9.comparatively higher
10.Easy set-up of equipment 10.Comparatively complex
General classification of Non Traditional machining
Based on Energy Source:
• Thermal Processes: These processes use heat energy to remove
material from the workpiece. Examples include laser cutting, laser
welding, plasma arc machining, and electron beam machining.
• Non-Thermal Processes: These processes do not rely on heat as the
primary energy source. Examples include abrasive jet machining,
waterjet cutting, and ultrasonic machining.
Based on Material Removal Mechanism:
• Mechanical Processes: Material removal is achieved through
mechanical actions such as cutting, grinding, or abrasion. Examples
include abrasive jet machining, grinding, and waterjet cutting.
• Electrochemical Processes: Material removal occurs through
controlled electrochemical reactions. Examples include electrochemical
machining (ECM) and electrochemical discharge machining (ECDM).
• Thermal Processes: Material is melted or vaporized by a heat source.
Examples include laser cutting, electron beam machining (EBM), and
plasma arc machining.
Department of Mechanical engineering,AIT Bangalore
Introduction to Non Traditional machining 2023-24
• Chemical Processes: Material is removed through chemical reactions,
often involving chemical etchants. Examples include chemical
machining and chemical milling.
• Ultrasonic Processes: Material is removed through high-frequency
vibrations generated by ultrasonic waves. Examples include ultrasonic
machining (USM) and ultrasonic- assisted machining (UAM).
• Based on Workpiece Material:
• Metal Machining Processes: Processes designed primarily for working
with metal materials, including ferrous and non-ferrous alloys.
• Ceramic and Composite Machining Processes: Processes tailored for
challenging materials like ceramics, advanced ceramics, and composite
materials.
• Polymer Machining Processes: Processes suited for machining
polymers and plastic materials.
• Based on Energy Delivery Mechanism:
• Conventional Machining Processes: Processes that involve
mechanical energy delivered through cutting tools. Examples include
milling, turning, and drilling.
• Non-Conventional Machining Processes: Processes that utilize
different energy delivery mechanisms, such as thermal, electrical, or
chemical, for material removal. Examples include EDM, laser cutting,
and abrasive jet machining.
Based on Application:
• Precision Machining: Processes that achieve extremely high precision
and tight tolerances. Examples include wire EDM (electrical discharge
machining), sinker EDM, and micro-machining.
• Surface Modification: Processes that alter the surface properties of a
material, such as surface hardening, surface texturing, and surface
coating.
• Microfabrication: Processes designed for producing micro-scale
components or features. Examples include micro-EDM, micro-laser
machining, and micro-milling.
• Macrofabrication: Processes suitable for larger-scale components and
products. Examples include waterjet cutting, laser cutting, and plasma
arc machining.
• Composite Machining: Processes tailored for working with composite
materials, often used in aerospace and automotive industries. Examples
include waterjet cutting of composites and abrasive waterjet
machining.
Department of Mechanical engineering,AIT Bangalore
Introduction to Non Traditional machining 2023-24
Classification based on Nature of Energy employed in machining:
a. Mechanical energy
➢ Ultrasonic machining (USM)
➢ Water jet machining (WJM)
➢ Abrasive jet machining (AJM)
b. Chemical or Electrochemical energy
➢ Electrochemical machining (ECM)
➢ Electrochemical Honing (ECH)
➢ Chemical machining (CM)
➢ Electrochemical grinding(ECG)
➢ Electrochemical deburring (ECD)
c.Thermal or Electrothermal energy
➢ Laser beam machining(LBM)
➢ Plasma arc machining(PAM)
➢ Electrical discharge machining (EDM)
➢ Electron Beam machining (EBM)
➢ Ion beam machining (IBM)
Selection of Non traditional machining process:
1. Properties of the work material
Soft,Hard,conducting ,non conducting, ductile ,Brittle
2. Shape to be machined
Ex:USM and LBM are not suitable for deep holes
ECM and EDM are good comparitively
3. Physical parameters of NTM process
Power,voltage potential,current,gap between tool and workpiece material
4. Process capabilities
Metal removal rate,surface finish,tolerance and other related parameters
5. Economic considerations
Capital investment,tooling and fixtures,power requirement and other expenses
Specific Advantages of NTM:
Department of Mechanical engineering,AIT Bangalore
Introduction to Non Traditional machining 2023-24
1. Capable to produce any geometrical shape with the desired finish,accuracy and
tolerance on any kind of material
2. Tool life is more
3. Free from change in microstructure
4. Can produce parts without any distortion ,burrs or inducing residual stresses
5. Chip handling and storage is not a problem
6. Easily automated
Limitations:
1. Initial cost of tooling and equipment is high
2. NTM involves too many processes parameters
3. Skilled operator
4. Machine set-up is very complex
5. Regular monitoring and maintenance of machine is essential
More power consumption
Applications :
1. Hard, difficult to cut materials like superalloys, nimonics,carbides,heat resisting steels
etc
2. Very thin and fragile parts, complex geometrical profiles with superior finish, accuracy
and tolerance preferred in aerospace, automotive,nuclear,mining and other sectors
3. Shaping hard cutting tools having complex geometrical profiles with much ease and
accuracy
4. Preparation of jewels for watch and timer movements
5. Removing glue and paint from leather objects and paintings
6. Engraving of products with alphanumeric or bar codes ,logos ,graphics and other
applications
Department of Mechanical engineering,AIT Bangalore
