Nontraditional Manufacturing Processes:

MF30604

A K Nath

Lecture No.-1

Introduction to NTMPs

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Fabrication of large

size domes

Fabrication of

Micro-lens

60m square hole Curved slot in SS

in Si mech14.weebly.com

3-D features inside transparent glass

Drilling hole and creating interconnect in

integrated circuits

Exotic components of different materials

Deep penetration welding

50-100 mm

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Conventional Machining Processes

Drilling

Turning

Milling

Circular symmetry mech14.weebly.com

Conventional Machining Processes (Material Removal):

Primarily rely on electrical motors and hard tool materials to perform tasks e.g.

Turning, Drilling, Boring, Milling, Shaping, Sawing, Slotting, & Grinding etc.

Main Characteristics of Conventional Machining:

* Material removal by chip formation

* Material removal by mechanical force

* Cutting tool – harder than work piece under machining condition

* Direct mechanical contact - residual mechanical & thermal stress.

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Demand for Products with

New exotic work materials: Improved mechanical, thermal, & chemical

properties

Super-alloys, ceramics and composites

* Too hard / brittle to machine with traditional process

* Materials too flexible / slender to cut or clamp

Ex: Machining Polycrystalline diamond

- fast wear of grinding wheel;

Silicon wafer, Ceramic – Damage during machining

60m square hole in Si Curved slot in SS

Micro-lenses

Quartz

Need of Nontraditional / Modern Manufacturing Processes !

Challenges & Competition in Manufacturing Industries:

New Products - Better Performance, More Features, More Durable, Less Production

Time, Energy Efficient, Low cost,

Innovative designs, complex shapes, high precision & high surface quality

* Stringent design requirements * Micro- Nano Sizes

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Other requirements of the New Manufacturing Process

Low machining cost

* Automated processing, Fast production

Photochemical Machining Electro-Discharge Machining

Rapid change of Product design

* Elimination of Traditional tooling to reduce time & cost:

Rapid Manufacturing

Less Temperature rise or residual stresses

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Modern / Nontraditional Manufacturing processes employing

New tools and

New forms of energy

Developed as

Efficient and economic alternatives to conventional ones

Often the first choice for certain technical requirements.

Modern / Nontraditional Manufacturing Processes differ to Traditional Mfg.

Processes in following aspects

Unconventional Energy Sources : Thermal, Chemical, Electrochemical, Kinetic

Energy ---

Nontraditional media to transfer energy from tool to work piece :

Photons, E-beam, Dielectric media, Electrolytic media, Water,

Abrasive slurry.

Processing usually not by direct MECHANICAL contact:

Nontraditional mechanism of interaction between tool and work piece:

Evaporation, Ablation, Melt Ejection, Dissolution, Erosion---- mech14.weebly.com

Basic NTM Process Groups:

* Thermal NTM Processes

- Laser Beam Machining (LBM)

- Electron Beam Machining (EBM)

- Plasma Arc Machining (PAC)

- Electrical Discharge Machining (EDM)

* Mechanical NTM Processes( Plastic deformation / Abrasive Erosion)

- Abrasive Jet Machining (AJM)

- Ultrasonic Machining (USM)

- Water Jet Machining (WJM)

- Abrasive Water Jet Machining (AWJM)

* Electrochemical NTM Processes

- Electrochemical Machining (ECM)

- Electrochemical Grinding (ECG)

* Chemical NTM Processes

- Chemical Machining (CHM)

- Thermo chemical Machining (TCM)

* Kinetic Energy ( Atom by atom knocking)

- Ion beam mech14.weebly.com

Characteristics of Modern / Non Traditional Machining (NTM) Processes:

Mostly NTM processes do not use mechanical energy for material removal.

They use different forms of energy for machining.

Example, USM, AJM, WJM - Mechanical energy

ECM- Electrochemical dissolution

Laser, EDM, EB - Thermal

Material removal with chip formation or even without chip formation

Example: AJM - Microscopic size chips

ECM - Electrochemical dissolution at atomic level

In NTM, Physical tool may or may not be present.

Example: Laser beam machining- No tool,

Electrochemical Machining- Physical tool needed

In NTM, Tool need not be harder than the work piece material.

Example: EDM, copper tool to machine hardened steels.

Nontraditional media for energy transfer:

EDM: Dielectric fluid,

Laser: Coherent photon beam mech14.weebly.com

Attributes of Nontraditional Machining Processes:

Increased Productivity: Faster operation

Reduction in the number of overall operations;

Reduced Rejection: Improved repeatability

Reduction in in-process breakage of fragile work piece.

Perform operation not feasible by traditional Manufacturing Processes,

Example drilling holes of very high depth to width aspect ratio, 100:1

Easy automation, On-line Process Monitoring & Control: Increased reliability,

repeatability; reduced human involvement

Versatile & Virtually unlimited Capability: Ex.- Laser can cut most materials of

any hardness: diamond, metals, concrete, glass, plastics, textiles, wood etc.

Drill holes of any diameter

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Course Outline by Topical Areas:

Introduction to Nontraditional Manufacturing Processes

Thermal Processing:

Electron Beam Machining (EBM): Fundamentals of Materials Processing (E-beam

machining, welding, lithography)

Laser Beam Machining (LBM): Fundamentals of Materials Processing- (Laser

cutting, drilling, welding, surface modification- hardening, alloying, cladding;

marking, micro-machining, laser rapid prototyping & manufacturing) Equipment for

Laser Beam Processing

Plasma Arc Machining (PAM): Cutting, Welding & Plasma Spraying

Ion-Beam Machining (IBM): Ion Beam removal, deposition, surface treatment

Mechanical NTM Processes( Plastic deformation / Abrasive Erosion)

- Abrasive Jet Machining (AJM)

- Ultrasonic Machining (USM)

- Water Jet Machining (WJM)

- Abrasive Water Jet Machining (AWJM)

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Objective of this course:

Learn about the basic theory, working principle, and characteristics of

different nontraditional manufacturing processes.

Identify critical process variables and their effect on process performance and

product quality

Develop mathematical model relating MRR with machining parameters

Develop understanding to properly assess the capabilities, limitations, and

potentials of nontraditional manufacturing processes

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Examples where NTM processes is the first choice

Intricate shaped blind holes- e.g. square holes of say 10x10mm with a depth of

20mm EDM / ECM

Machining hard materials- e.g. Diamond, Inconel, Ti-Alloys, Composites,

Ceramics or Carbides EDM, ECM, LBM

Small diameter holes with large aspect ratio (0.5mm , 10mm l)

LBM, EBM, EDM

Flexible , Brittle materials WJ, AWJ, EDM, PCM, LBM, EBM

Laser Cutting

Abrasive Machining

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Course Materials : Lecture Notes

Reference Books :

1. Nontraditional Manufacturing Processes

Gary F. Benedict, Marcel Dekker,Inc

2. Modern Machining Processes

P C Pandey & H S Shan, Tata McGraw-Hill

3. Nonconventional Machining

P K Mishra, Narosa Publishing House

4. Manufacturing Science

Amitabha Ghosh & A K Mallik, Affiliated East-West Press

5. www.nptel.iitm.ac.in

National Programme on Technology Enhanced Learning (NPTEL)

Course- IIT Kharagpur- Manufacturing-Module 9 (on NTM)

Lessons 35-40.

6. Laser Material Processing, by W M Steen mech14.weebly.com