STANI MEMORIAL COLLEGE OF ENGINEERING & TECHNOLOGY

PHAGI, JAIPUR-303005

DEPARTMENT OF COMPUTER ENGINEERING

CERTIFICATE

This is certified that seminar work entitled “Non-traditional Machining Methods” is a

bonafide work carried out in the eight semester by “Ashutosh Kumar” in partial

fulfillment for the award of Bachelor of Technology in “Mechanical Engineering” from

Rajasthan technical university, Kota during Academic year 2010-2011 who carried out

the seminar under the guidance and no part of this work has been submitted earlier for the

award of any degree.

SIGNATURE SIGNATURE

Mr. Vinay Sing Marval Mr. Yudhistir Saini

SEMINAR CO-ORDINATOR GUIDE

(HEAD OF DEPT.) (LECTURER)

(DEPT. OF MECHANICAL ENGG.) (DEPT. OF MECHANICAL ENGG.)

SIGNATURE

Mr. VINAY SINGH MARVAL

HEAD OF DEPARTMENT (ME)

ACKNOWLEDGMENT

A scholarly and quality work like designing of any seminar can be accomplished by

motivation, guidance and inspiration of certain quarters besides the individual efforts. Let

me in this page express my heartiest gratitude to all those who helped me in various

stages of this study.

I am very much thankful to Mr. Vinay Singh Marval, Head of Department (ME) for

giving me the permission to undergo this seminar and providing all the necessary

facilities.

During my seminar period all the staff members of department have helped us with their

skills. Here by I express our sincere thanks to my guide Mr. Yudhistir Saini whose

valuable guidance and kind cooperation, without which this seminar would have not been

possible.

ABSTRACT

Most of the machining processes are involved with removal of chips using traditional

machining techniques like turning, drilling, milling, grinding, etc. However, there are

situations where these processes are not satisfactory, economical or even possible. If the

work material is very hard or too flexible, shape of the part is complex or the requirement

of accuracy and surface finish is high, traditional machining techniques are not

appropriate in those cases, but nontraditional machining techniques can be applied

successfully. Now a days nontraditional machining techniques are being widely used in

many of the modern industries like automotive industries, aerospace industries, electronic

industries and others. 

TABLE OF CONTENTS

CHAPTER PAGE NO

1. INTRODUCTION 1

2. LITERATURE SURVEY 2

3. METHODOLOGY 4

4. PROCEDURES 5

5. RESULT ANALYSIS AND DISCUSSION 10

6. CONCLUSION 13

7. SCOPE OF FUTURE WORK 19

8. APPENDICES 20

9. REFERENCES 21

LIST OF FIGURES

1. FINITE CAPACITY ROUGH SCHEDULING 3

LIST OF SYMBOLS, ABBREVIATION AND

NOMENCLATURE

1. ABBREVIATIONS

TOC – THEORY OF CONSTRAINT

DBR – DRUM BUFFER REPORT

RT – REPLENISHMENT TIME

VMI –VENDOR MANAGED INVENTORY

INTRODUCTION

Manufacturing processes can be broadly divided into two groups and they are primary

manufacturing processes and secondary manufacturing processes. The former ones

provide basic shape and size to the material as per designer’s requirement. Casting,

forming, powder metallurgy are such processes to name a few. Secondary manufacturing

processes provide the final shape and size with tighter control on dimension, surface

characteristics etc. Material removal processes are mainly the secondary manufacturing

processes.

Material removal processes once again can be divided into mainly two groups and they

are “Traditional Machining Processes” and “Non-Traditional Manufacturing Processes”.

Examples of traditional machining processes are turning, boring, milling, shaping,

broaching, slotting, grinding etc. Similarly, Abrasive Jet Machining (AJM), Ultrasonic

Machining (USM), Water Jet and Abrasive Water Jet Machining (WJM and AWJM),

Electro-discharge Machining (EDM) are some of the Non Traditional Machining (NTM)

Processes.

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LITERATURE SURVEY

A literature review is part of a research project where a researcher researches on similar

work to his or hers. This very important part of the research helps the researcher to find

out how other researchers have tackled the problem he/she is attempting to solve. It gives

insight on how to go about solving the problem at hand and provides information on

available technologies and tools for solving the problem.

Traditional machining, one of the most important material removal methods, is a

collection of material-working processes in which power-driven machine tools, such as

saws, lathes, milling machines, and drill presses, are used with a sharp cutting tool to

mechanically cut the material to achieve the desired geometry. Machining is a part of the

manufacture of almost all metal products, and it is common for other materials, such as

wood and plastic, to be machined. A person who specializes in machining is called a

machinist. A room, building, or company where machining is done is called a machine

shop. Much of modern day machining is controlled by computers using computer

numerical control (CNC) machining. Machining can be a business, a hobby, or both.

The precise meaning of the term "machining" has evolved over the past 1.5 centuries as

technology has advanced. During the Machine Age, it referred to (what we today might

call) the "traditional" machining processes, such as turning, boring, drilling, milling,

broaching, sawing, shaping, planning, reaming, and tapping, or sometimes to grinding.

Since the advent of new technologies such as electrical discharge machining,

electrochemical machining, electron beam machining, photochemical machining, and

ultrasonic machining, the retronym "traditional machining" can be used to differentiate

the classic technologies from the newer ones. The term "machining" without qualification

usually implies traditional machining.

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METHODOLOGY

The three principal machining processes are classified as turning, drilling and milling.

Other operations falling into miscellaneous categories include shaping, planing, boring,

broaching and sawing.

Turning operations are operations that rotate the workpiece as the primary method

of moving metal against the cutting tool. Lathes are the principal machine tool

used in turning.

Milling operations are operations in which the cutting tool rotates to bring cutting

edges to bear against the workpiece. Milling machines are the principal machine

tool used in milling.

Drilling operations are operations in which holes are produced or refined by

bringing a rotating cutter with cutting edges at the lower extremity into contact

with the workpiece. Drilling operations are done primarily in drill presses but

sometimes on lathes or mills.

Miscellaneous operations are operations that strictly speaking may not be

machining operations in that they may not be swarf producing operations but

these operations are performed at a typical machine tool. Burnishing is an

example of a miscellaneous operation. Burnishing produces no swarf but can be

performed at a lathe, mill, or drill press.

An unfinished workpiece requiring machining will need to have some material cut away

to create a finished product. A finished product would be a workpiece that meets the

specifications set out for that workpiece by engineering drawings or blueprints. For

example, a workpiece may be required to have a specific outside diameter. A lathe is a

machine tool that can be used to create that diameter by rotating a metal workpiece, so

that a cutting tool can cut metal away, creating a smooth, round surface matching the

required diameter and surface finish. A drill can be used to remove metal in the shape of

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a cylindrical hole. Other tools that may be used for various types of metal removal are

milling machines, saws, and grinding machines. Many of these same techniques are used

in woodworking.

More recent, advanced machining techniques include electrical discharge machining

(EDM), electro-chemical erosion, laser cutting, or water jet cutting to shape metal

workpieces.

As a commercial venture, machining is generally performed in a machine shop, which

consists of one or more workrooms containing major machine tools. Although a machine

shop can be a stand-alone operation, many businesses maintain internal machine shops

which support specialized needs of the business.

Machining requires attention to many details for a workpiece to meet the specifications

set out in the engineering drawings or blueprints. Besides the obvious problems related to

correct dimensions, there is the problem of achieving the correct finish or surface

smoothness on the workpiece. The inferior finish found on the machined surface of a

workpiece may be caused by incorrect clamping, a dull tool, or inappropriate presentation

of a tool. Frequently, this poor surface finish, known as chatter, is evident by an

undulating or irregular finish, and the appearance of waves on the machined surfaces of

the workpiece.

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PROCEDURES

To classify Non Traditional Machining Processes (NTM), one needs to understand and

analyse the differences and similar characteristics between traditional machining

processes and NTM processes.

Traditional Machining Processes mostly remove material in the form of chips by

applying forces on the work material with a wedge shaped cutting tool that is harder than

the work material under machining condition. Such forces induce plastic deformation

within the work piece leading to shear deformation along the shear plane and chip

formation. Fig. below depicts such chip formation by shear deformation in traditional

machining.

Shear deformation in traditional machining leading to chip formation.

Thus the major characteristics of traditional machining are:

• Generally macroscopic chip formation by shear deformation

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• Material removal takes place due to application of cutting forces – energy

domain can be classified as mechanical

• Cutting tool is harder than work piece at room temperature as well as under

machining conditions

Non Traditional Machining (NTM) Processes on the other hand are characterised as

follows:

• Material removal may occur with chip formation or even no chip formation may

take place. For example in AJM, chips are of microscopic size and in case of

Electrochemical machining material removal occurs due to electrochemical

dissolution at atomic level

• In NTM, there may not be a physical tool present. For example in laser jet

machining, machining is carried out by laser beam. However in

Electrochemical Machining there is a physical tool that is very much required

for machining

• In NTM, the tool need not be harder than the work piece material. For example,

in EDM, copper is used as the tool material to machine hardened steels.

• Mostly NTM processes do not necessarily use mechanical energy to provide

material removal. They use different energy domains to provide machining.

For example, in USM, AJM, WJM mechanical energy is used to machine

material, whereas in ECM electrochemical dissolution constitutes material

removal.

Thus classification of NTM processes is carried out depending on the nature of energy

used for material removal. The broad classification is given as follows:

• Mechanical Processes

Abrasive Jet Machining (AJM) ⎯ Ultrasonic Machining (USM) ⎯ Water Jet Machining (WJM) ⎯

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Abrasive Water Jet Machining (AWJM) ⎯• Electrochemical Processes

Electrochemical Machining (ECM) ⎯ Electro Chemical Grinding (ECG) ⎯ Electro Jet Drilling (EJD) ⎯

• Electro-Thermal Processes

Electro-discharge machining (EDM) ⎯

Laser Jet Machining (LJM)

Electron Beam Machining (EBM) ⎯• Chemical Processes

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

Schematic representation of various metal cutting operations

Traditional machining sufficed the requirement of the industries over the decades. But

new exotic work materials as well as innovative geometric design of products and

components were putting lot of pressure on capabilities of traditional machining

processes to manufacture the components with desired tolerances economically. This led

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to the development and establishment of NTM processes in the industry as efficient and

economic alternatives to traditional ones. With development in the NTM processes,

currently there are often the first choice and not an alternative to traditional processes for

certain technical requirements. The following examples are provided where NTM

processes are preferred over the traditional machining process:

o Intricate shaped blind hole – e.g. square hole of 15 mmx15 mm with a

depth of 30 mm

o Difficult to machine material – e.g. same example as above in Inconel, Ti-

alloys or carbides.

o Low Stress Grinding – Electrochemical Grinding is preferred as compared

to traditional grinding

o Deep hole with small hole diameter – e.g. φ 1.5 mm hole with l/d = 20

o Machining of composites.

Abrasive Jet Machining

In Abrasive Jet Machining (AJM), abrasive particles are made to impinge on the work

material at a high velocity. The jet of abrasive particles is carried by carrier gas or air.

The high velocity stream of abrasive is generated by converting the pressure energy of

the carrier gas or air to its kinetic energy and hence high velocity jet. The nozzle directs

the abrasive jet in a controlled manner onto the work material, so that the distance

between the nozzle and the work piece and the impingement angle can be set desirably.

The high velocity abrasive particles remove the material by micro-cutting action as well

as brittle fracture of the work material. Fig. below schematically shows the material

removal process.

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Schematic representation of AJM

AJM is different from standard shot or sand blasting, as in AJM, finer abrasive grits are

used and the parameters can be controlled more effectively providing better control over

product quality.

In AJM, generally, the abrasive particles of around 50 μm grit size would impinge on the

work material at velocity of 200 m/s from a nozzle of I.D. of 0.5 mm with a stand off

distance of around 2 mm. The kinetic energy of the abrasive particles would be sufficient

to provide material removal due to brittle fracture of the work piece or even micro cutting

by the abrasives.

Equipment

In AJM, air is compressed in an air compressor and compressed air at a pressure of

around 5 bar is used as the carrier gas as shown in Fig. below it also shows the other

major parts of the AJM system. Gases like CO2, N2 can also be used as carrier gas which

may directly be issued from a gas cylinder. Generally oxygen is not used as a carrier gas.

The carrier gas is

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AJM set-up

first passed through a pressure regulator to obtain the desired working pressure. The gas

is then passed through an air dryer to remove any residual water vapour. To remove any

oil vapour or particulate contaminant the same is passed through a series of filters. Then

the carrier gas enters a closed chamber known as the mixing chamber. The abrasive

particles enter the chamber from a hopper through a metallic sieve. The sieve is

constantly vibrated by an electromagnetic shaker. The mass flow rate of abrasive (15

gm/min) entering the chamber depends on the amplitude of vibration of the sieve and its

frequency. The abrasive particles are then carried by the carrier gas to the machining

chamber via an electro-magnetic on-off valve. The machining enclosure is essential to

contain the abrasive and machined particles in a safe and eco-friendly manner. The

machining is carried out as high velocity (200 m/s) abrasive particles are issued from the

nozzle onto a work piece traversing under the jet.

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RESULT ANALYSIS AND DISCUSSION

Relative motion is required between the tool and work to perform a machining operation.

The primary motion is accomplished at a certain cutting speed. In addition, the tool must

be moved laterally across the work. This is a much slower motion, called the feed. The

remaining dimension of the cut is the penetration of the cutting tool below the original

work surface, called the depth of cut. Collectively, speed, feed, and depth of cut are

called the cutting conditions. They form the three dimensions of the machining process,

and for certain operations, their product can be used to obtain the material removal rate

for the process:

where

— the material removal rate in mm3/s, (in3/s), — the cutting speed in m/s, (ft/min),

— the feed in mm, (in), — the depth of cut in mm, (in).

Note: All units must be converted to the corresponding decimal (or USCU) units

.

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APPLICATIONS

For drilling holes of intricate shapes in hard and brittle materials

For machining fragile, brittle and heat sensitive materials

AJM can be used for drilling, cutting, deburring, cleaning and etching.

Micro-machining of brittle materials

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CONCLUSION

The non-traditional methods of machining have several specific advantages over

traditional methods of machining. It makes tasks look easier. These methods are not

limited by hardness, toughness, and brittleness of materials and can produce any intricate

shape on any workpiece material by suitable control over the various physical parameters

of the processes. These methods find place in production treatment to produce several

products with better quality and exact values and minimum cost.

Despite the traditional methods as recent advancements non-traditional methods are

adequate to machine, any type of materials from stand point of economic production. The

word untraditional is used in the sense that the metal slide hastalloy, nitraalloy,

mnemonics are such that they can’t be machined by traditional methods but require some

special techniques where the untraditional methods stand firmly. So now a day’s even

having traditional methods as advancement several industries prefer the non-traditional

methods.

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SCOPE OF FUTURE WORK

Non-traditional machining includes a large scope of technologies. In the past, non-

traditional machining processes were developed for applications that are not practical or

cost efective when using traditional machining methods. Four common non-traditional

process are as follows: Abrasive Waterjet, Electrical Discharge, Laser, and Ultrasonic.

The future is unknown, but these non-traditional machining processes are quickly

becoming the primary methods for machining new and complex materials types..

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APPENDICES

APPENDIX 1: PROJECT SPECIFICATION

STANI MEMORIAL COLLEGE OF ENGINEERING AND

TECHNOLOGY

FOR: Ashutosh Kumar

TOPIC: Non-traditional Machining Methods

SUPERVISOR: Mr. Yudhisthir Saini

SPONSORSHIP: Smcet, RTU

PROJECT AIM: Nontraditional machining can be thought of as operations that do not

use shear as their primary source of energy. The aim of this project is to apply the

concept of non-traditional machining and show its various advantages in the field of

mechanics.

PROGRAMME:

1. Literature Review

2. Method

3. Working

4. Result

AGREED

________________ (Student), _______________(Supervisor)

___/___/___ ___/___/ ___ ___/___/___

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REFERENCES

1.  http://www.wire-cut.co.uk/wireedm.htm

2.  The History of EDM, retrieved 2010-08-05

3.  Experience Agie, retrieved 2009-11-02.

4.  What is wire EDM?, retrieved 2009-11-02.

5.  Naotake Mohria, Yasushi Fukuzawab, Takayuki Tanic, Nagao Saitoa and

Katsushi Furutani. Assisting Electrode Method for Machining Insulating

Ceramics. CIRP Annals - Manufacturing Technology. Volume 45, Issue 1, 1996,

Pages 201-204.doi:10.1016/S0007-8506(07)63047-9

6.  Y.H. Liu, X.P. Lia, R.J. Jia, L.L. Yua, H.F. Zhanga and Q.Y. Li. Effect of

technological parameter on the process performance for electric discharge milling

of insulating Al2O3 ceramic. Journal of Materials Processing Technology.

Volume 208, Issues 1-3, 21 November 2008, Pages 245-

250. doi:10.1016/j.jmatprotec.2007.12.143

7.  Chris J Morgan, R Ryan Vallance and Eric R Marsh. Micro machining glass

with polycrystalline diamond tools shaped by micro electro discharge machining.

Journal of Micromechanics and Microengineering, 2004, volume 14, 1687-

1692 doi:10.1088/0960-1317/14/12/013

8.  Willard J. McCarthy, Joseph A. McGeough Machine tool article of the

Enciclopaedia Britannica URL [1]

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