Investigate Surface Integrity When Machining FC300 Cast Iron Using Uncoated Carbide Ball End Mill - Study Of Subsurface Micrograph.

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UNIVERSITI TEKNIKAL MALAYSIA MELAKA

INVESTIGATE SURFACE INTEGRITY WHEN MACHINING

FC300 CAST IRON USING UNCOATED CARBIDE BALL END

MILL: STUDY OF SUBSURFACE MICROGRAPH

This report submitted in accordance with requirement of the Universiti Teknikal Malaysia Melaka (UTeM) for the Bachelor Degree of Manufacturing Engineering

(Manufacturing Process) (Hons.)

MOHAMAD AFIQ BIN SHAWALDIN B050910051

900719 – 10 – 5043

FACULTY OF MANUFACTURING ENGINEERING 2013

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UNIVERSITI TEKNIKAL MALAYSIA MELAKA

BORANG PENGESAHAN STATUS LAPORAN PROJEK SARJANA MUDA

TAJUK: Investigate Surface Integrity When Machining FC300 Cast Iron Using

Uncoated Carbide Ball End Mill: Study Of Subsurface Micrograph

SESI PENGAJIAN: 2012/13 Semester 2

Saya MOHAMAD AFIQ BIN SHAWALDIN

mengaku membenarkan Laporan PSM ini disimpan di Perpustakaan Universiti Teknikal Malaysia Melaka (UTeM) dengan syarat-syarat kegunaan seperti berikut:

1. Laporan PSM adalah hak milik Universiti Teknikal Malaysia Melaka dan penulis.

2. Perpustakaan Universiti Teknikal Malaysia Melaka dibenarkan membuat salinan

untuk tujuan pengajian sahaja dengan izin penulis.

3. Perpustakaan dibenarkan membuat salinan laporan PSM ini sebagai bahan

pertukaran antara institusi pengajian tinggi.

4. **Sila tandakan (√)

SULIT

TERHAD

TIDAK TERHAD

(Mengandungi maklumat yang berdarjah keselamatan atau kepentingan Malaysia sebagaimana yang termaktub dalam AKTA RAHSIA RASMI 1972)

(Mengandungi maklumat TERHAD yang telah ditentukan oleh organisasi/badan di mana penyelidikan dijalankan)

(TANDATANGAN PENULIS)

Alamat Tetap: Blok 49-1-10 ,

Perumahan Polis Desa Tasik, 57000 Sg Besi, KUALA LUMPUR.

Disahkan oleh: (TANDATANGAN PENYELIA)

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DECLARATION

I hereby, declared this report entitled “Investigate Surface Integrity When Machining FC300 Cast Iron Using Uncoated Carbide Ball End Mill: Study of Subsurface

Micrograph” is the results of my own research except as cited in references.

Signature :

Author’s Name : Mohamad Afiq Bin Shawaldin

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APPROVAL

This report is submitted to the Faculty of Manufacturing Engineering of UTeM as a partial fulfillment of the requirements for the degree of Bachelor of Manufacturing Engineering (Manufacturing Process) (Hons.). The member of the supervisory committee is as follows:

……… (Official Stamp of Principal Supervisor)

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ABSTRAK

Tujuan kajian ini adalah untuk mengkaji integriti FC300 ‘cast iron’ selepas proses pemesinan dalam konteks kekasaran permukaan dan tekstur permukaan. FC300 ‘cast iron’ merupakan satu bahan yang selalu digunakan didalam industri pembuatan acuan. Parameter yang akan dinilai berdasarkan 6000 - 9000 rpm kelajuan pemutaran, 4 - 7 m/min kadar suapan dan dengan nilai yang sama untuk pemotongan dalaman sebanyak 0.1mm. Didalam kajian ini, percubaan pemesinan akan dijalankan menggunakan mesin ‘milling’ didalam keadaan kering dan alat pemotongan yang akan digunakan ialah ‘uncoated carbide ball end mill’ dengan diameter 32mm. Prestasi integriti permukaan FC300 ‘cast iron’ akan diambil kira oleh subpermukaan mikrohardness dan subpermukaan mickostructure. Kajian ini akan menyediakan maklumat yang berguna tentang parameter pemotongan yang sesuai untuk FC300 ‘cast iron’ dengan cekap.

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ABSTRACT

The aim of this research is to study the surface integrity of FC300 cast iron after machining in terms of subsurface microstructure and subsurface microhardness. FC300 is a material that frequently used in die industry. The parameters that was evaluated are based on the 6000 – 9000 rpm spindle speed, 4 – 7 m/min feed rate and with a constant depth of cut 0.1mm. In this research, the machining trial was conducted using a CNC milling machine under dry condition and the cutting tool that is used was uncoated carbide ball end mill with diameter 32mm. The performance of surface integrity for FC300 cast iron was measured and analysed in regards towards the subsurface microhardness and subsurface microstructure. This research will provide useful information about the suitable cutting parameter to machining FC300 cast iron efficiently.

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DEDICATION

First and foremost, , I would like to express my greatest appreciation to Universiti Teknikal Malaysia Melaka for giving me the opportunity to undergo my final year

“Projek Sarjana Muda” under the supervision of Dr. Mohd Hadzley Bin Abu Bakar. A special thank you also goes to my supervisor Dr. Mohd Hadzley Bin Abu Bakar for his dedication and guidance during the period of undergoing my project. Last but not least, I want to thank my mom and dad for their support as well as to all my friends who never

give up encouraging me to complete this report.

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ACKNOWLEDGEMENT

Bissmillahirrahmanirrahim,

Personally, I would like to thank Universiti Teknikal Malaysia Melaka for the

opportunity given me to undergo my “Projek Sarjana Muda 2” at the year 4 semester 2 in my studies.

My heartiest appreciation especially to:

• Dr. Mohd. Hadzley B. Abu Bakar , Lecturer of Faculty Manufacturing

Engineering, Universiti Teknikal Malaysia Melaka, supervisor for my Projek Sarjana Muda 2 that had give guide, support and information for me to undergo and completely done my Projek Sarjana Muda .

• Associated Profesor Dr. Sivarao, Lecturer of Faculty Manufacturing

Engineering, Universiti Teknikal Malaysia Melaka, as the head of supervisor for this Projek Sarjana Muda.

It was their kind efforts that have given me the opportunity and guidance to successfully undergo my “Projek Sarjana Muda ” in the final year.

Last but not least, I would like to thank all my friends that give full support and also not forgetting my family for their support and encouragement in completing my final year

project.

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TABLE OF CONTENT

Abstrak i

Abstract ii

Dedication iii

Acknowledgement iv

Table of Content v

List of Table viii

List of Figure ix

List of Abbreviations xii

CHAPTER 1: INTDOCUTION 1

1.0 Introduction 1

1.1 Objective 4

1.2 Problem Statement 4

CHAPTER 2: LITERATURE REVIEW 5

2.1 Machining 5

2.1.1 Dry Machining 6

2.1.2 Element of Machining 8

2.2 Milling Process 9

2.2.1 Fundamental of Milling Process 10

2.2.2 CNC Milling 5-axis 11

2.3 Cutting Tool 11

2.3.1 Type of Milling Cutter 12

2.3.2 Cutting Tool Materials 16

2.3.2.1 High Speed Steel 17

2.3.2.2 Carbides or Sintered Carbides 19

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2.3.2.4 Diamond 20

2.3.2.5 Alumina Base Ceramic 21

2.3.2.6 Uncoated Carbide 21

2.3.3 Common Coating Material for Cutting Tool 22

2.3.3.1 Titanium Nitride 22

2.3.3.2 Titanium Carbide 22

2.3.3.3 Aluminium Oxide 23

2.3.4 Common Process for Tool Coating 23

2.3.4.1 Chemical Vapor Deposition 23

2.3.4.2 Physical Vapor Deposition 25

2.4 Cast Iron 26

2.4.1 Type of Cast Iron 27

2.4.1.1 White Cast Iron 27

2.4.1.2 Chilled Cast Iron 28

2.4.1.3 Gray Cast Iron 29

2.4.1.4 Ductile Cast Iron 30

2.4.2 FC300 Cast Iron 31

2.4.2.1 Composition of FC300 Cast Iron 31

2.5 Surface Integrity 32

2.5.1 Surface Roughness 32

2.5.2 Surface Texture 33

2.5.3 Surface Profile 35

2.5.4 Surface Defect 36

2.5.5 Type of Defect 38

2.5.6 Measuring Surface Finish 41

2.5.7 Effect of Cutting Parameter 42

2.5.8 Subsurface Microstructure 42

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CHAPTER 3: METHODOLOGY 45

3.1 Introduction 45

3.2 Flow Chart 46

3.3 Work Material 47

3.4 Cutting Tool 49

3.4.1 Indexable Milling Tool 49

3.4.2 Insert 50

3.5 Machining Performance 51

3.5.1 CNC Milling 5-Axis 51

3.5.2 Cutting Condition 52

3.6 Performance Measure 53

3.6.1 Tool and Workpiece Specimen Preparation 54

3.6.2 Subsurface Microstructure 55

3.6.3 Subsurface Microhardness 56

CHAPTER 4: RESULTS AND ANALYSIS 58

4.1 Microstructure 58

4.1.1 Microstructure Alterations 59

4.1.2 White Layer Formation 62

4.2 Subsurface Microhardness 64

CHAPTER 5: CONCLUSIONS AND RECOMMENDATIONS 70

5.1 Conclusions 70

5.2 Recommendations 71

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LIST OF TABLE

2.1 General Composition of FC300 31

3.1 Tensile strength of gray cast iron 48

3.2 Bending resistant properties and hardness of gray cast iron 48

3.3 Chemical composition of FC300 cast iron 48

3.4 Specification parameter of ball end mill Hitachi ABPF-32MT4 48 3.5 Specification parameter of insert SRFT 30 VP15TF 50

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LIST OF FIGURE

2.1 Elements of Machining Process 8

2.2 Example of Milling Process 9

2.3 DMF 250 Linear Deckel Maho 11

2.4 Geometry of End Mill 13

2.5 Hob Cutter 14

2.6 Vertical Hobbing Machine 14

2.7 Fly Cutter 15

2.8 Brass Wheels Being Cut by a Fly Cutter 15

2.9 Geometry of a Ball Nose Milling Cutter and its Static Solid Model 16 2.10 Enlarged Image of a Ball Nose Cutter Tool Tip Using SEM 16

2.11 Schematic Diagram CVD Coating Method 24

2.12 Schematic Diagram of PVD Process 26

2.13 Metal Alloy Classification 27

2.14 White Cast Iron 28

2.15 Chilled Cast Iron 29

2.16 Gray CI, Fe, 3.2 C, and 2.5 Si wt%, 30

2.17 Microstructure for Ferrictic Ductile Cast Iron 31

2.18 Surface Characteristic 34

2.19 Surface Symbol 35

2.20 Example of surface defects 37

2.21 Surface Defects 38

2.22 Microcracks 39

2.23 Plastic Deformation 39

2.24 Slip 40

2.25 Twinning 41

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3.1 Research Methodlogy 46

3.2 The Main Grey Cast Iron Grades Worldwide 47

3.3 Ball End Mill 32mm (Hitachi ABPF-32 MT4) 45

3.4 Insert for Ball End Mill 32mm 50

3.5 DMF 250 Linear Deckel Maho 51

3.6 Range cutting speed (m/min) for machining a different workpiece material 52

3.7 Automatic Moulding Machine 53

3.8 Automatic Grinding/Polishing Equipment 54

3.9 Scanning Electron Microscope 55

3.10 Rockwell Hardness Tester Mitutoyo Wizhard HR-500 56

4.1 Microstructure of the grey cast iron 58

4.2 Microstructure bent when machining at cutting speed of 6000 rpm, 60 feed rate of 5 m/min, and depth of cut of 0.1 mm.

4.3 Microstructure bent when machining at cutting speed of 7000 rpm, 60 feed rate of 5 m/min, and depth of cut of 0.1 mm.

4.4 Microstructural alteration in FC300 cast iron 61

4.5 White layer formation under condition of cutting parameter 8000 rpm, 63 feed rate of 7 m/min and depth of cut of 0.1 mm

4.6 Hardness variations after machining FC 300 cast iron with dry machining 65 under the conditions where the cutting speed is 6000 rpm, depth of cut of 0.1 mm/min

4.7 Hardness variations after machining FC 300 cast iron with dry machining 66 under the conditions where the cutting speed is 7000 rpm, depth of cut of 0.1 mm/min.

4.8 Hardness variations after machining FC 300 cast iron with dry machining 66 under the conditions where the cutting speed is 8000 rpm, depth of cut of 0.1 mm/min.

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4.9 Hardness variations after machining FC 300 cast iron with dry machining 67 under the conditions where the cutting speed is 9000 rpm, depth of cut of 0.1 mm/min.

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LIST OF ABBREVIATIONS

MMSB - Miyazu Malaysia Sdn Bhd

UTeM - Universiti Teknikal Malaysia Melaka ASTM - American Society for Testing and Material JIS - Japanese Industrial Standard

SEM - Scanning Electron Microscope Cbn - Cubic Boron Nitride

CNC - Computer Numerical Method HSM - High Speed Machine

HSS - High Speed Spindle

MRR - Material Removal Rate

Ra - Arithmetic Average

Rpm - Revolution per Minute HIP - Hot Isostatic Pressing CVD - Chemical Vapor Deposition PVD - Physical Vapor Deposition

WC - Tungsten Carbide

TiN - Titanium Nitride

TiC - Titanium Carbide

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CHAPTER 1 INTRODUCTION

1.1 Introduction

A die is basically a tool that can be used in the industry especially in the manufacturing industry either to cut or shape the material using a press. In nowadays technology, product that can be made from dies range from a simple pin clip to a more complex geometry figure such as a body car used in the automotive industry. In the automotive industry for example, there are two most common die operation used which is bending where it may create a curved bend such as for the door part of the car and other operation is known as blanking where the process will produce a flat piece of material by cutting the desired shape according to the customer specification in one operation.

Nowadays, processing of a die to be used in the manufacturing industry is very complicated and hard to produce. Among the constraints is its high material hardness, short lead time and also its complex work piece geometry due to the demands of the customers. In addition, the aspect of quality becomes a hot issue due to intensified competition and quality awareness. Miyazu Malaysia Sdn. Bhd. (MMSB), located at Tanjung Malim, Perak has a core business which closely related to the manufacturing of die. This company specializes in automotive tooling engineering and also design and manufacturing services. One of its great achievements until present is that this company is currently the leading of die provider for Proton cars. With over two decades of experience in the manufacturing of die, sharing of knowledge and technology with

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MBSB will benefit many people especially those who involve in the research of die machining in general.

Among the most widely used material in stamping die application is cast iron. Cast iron is a type of iron-carbon cast alloy with various elements on it that is made by remelting scrap, pig iron, and other addition. For differentiation from steel and cast steel, cast iron

is deﬁned as a cast alloy with a carbon content (min 2.03%) that ensures the

solidiﬁcation of the ﬁnal phase with a eutectic transformation. Usually, normal grade of

cast iron is widely used as an engineering material even though it is quite brittle and are not strong enough. It is due to other aspects such as very good machinability, ease of melting and casting, cheap prices, ability to resist wear and compressive strength and last but not least is that it has high amount of fluidity which makes it easy to cast into a complex shape. In this research, the grade of cast iron that will be used is FC300 according to the Japanese Industrial standard (JIS) code G5501. In general, due to the presence of more refined graphite and the matrix which is essentially pearlite, it gives this FC300 more mechanical resistance and because of that, it gives a better surface finish and higher hardness. Other than that, one of the most important aspects of this FC300 is its ability to resist leaking. This characteristic is very crucial to some application that applied hydraulic components subjected to high pressure such as valve bodies, manifolds, heads, caps and plungers. With regards, according to the American Society for Testing and Material (ASTM) A48, class 40, the specification is similar to it.

Machining with high speeds (HSM) is one of the modern technologies, which in comparison with conventional cutting enables to increase efficiency, accuracy and quality of work pieces and at the same time to decrease the costs and machining time (Schulz, 1992). Practically, it can be noted that HSM is not simply high cutting speed. It should be regarded as a process where the operations are performed with very specific methods and production equipment (Coromant, 1999). Basically the main process that involves in HSM has considerably higher feedrates and cutting speed compared to conventional machining such as lathe and milling machine. Among the main contributes of HSM is the reduction of maximum surface roughness when applied it to the finishing

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operation of die’s machining. In addition, HSM also offers other advantages such as shorten the production time and increase the accuracy of machined parts.Due to the fact, the material removal rate in high speed machining can be 5–10 times higher than conventional machining and the process also capable of reducing machining lead-time. In the nutshell, by using HSM, not only it will reduce the manual polishing but also the surface finishing can be greatly improved.

Thus, the aim of this project is to study the best parameters to be used when using FC300 cast iron to produce fine surface integrity for the application of die stamping. In this research, a 5-axis CNC milling machine was used and for the surface finish of FC300 cast iron, it undergone different cutting parameters of cutting speed (v) and federates (f) while for the depth of cut, it is constant. The works was carried out in close cooperation with the Miyazu Malaysia Sdn. Bhd. The understanding and correct use of the cutting parameters in high speed machining lead to better understanding in surface integrity of cast iron which is through to the step by increase a cutting speed and feed rate .By the end of the day, the data gathered from the experiment was used to provide sufficient information in order to get fine surface finishing during machining die based material without having secondary work such as polishing. In addition, the data obtained can be used to help machinist and another researcher in the future in order to get a better surface finish, less working processing and also optimizing the operational cost.

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1.2 Objective

The overall aim of this research is to study the surface integrity of FC300 cast iron. The aim can be resolved into the following specific objectives:

a) To analyze the surface integrity of FC 300 cast iron after machining based on: i) Subsurface microstructure and

ii) Subsurface microhardness

1.3 Problem Statement

In order to fabricate molds and die, several processing steps need to be done such as initial rough machining where the excess material was removed quickly and then it undergoes a semi finishing where the process will ensure a consistent material removal rate of the materials. Then it will undergo some machining processing where at this step it will have a good dimensional accuracy and better surface finish before it undergo the last processing which is polishing that will ensure the surface of the material become shiny and high quality of surface finish. The overall process required a certain amount of time and more workers need to be hired thus result in higher cost operation. Basically, the entire machine at MMSB that involved with the manufacturing of dies was machined by using a constant parameter which is feed rates of 5.5 m/min and also cutting speed of 6000 rpm. In addition, MMSB has to hire three personnel to polish the dies manually after the semi finishing process in order to get a fine surface finish. In such cases, there are certain problems that MMSB had detect regarding on human error where as the polishing is not uniform at all side.

As getting inspiration from this kind of situations, this paper consists of research that was done to eliminate or reduce the step for manufacture stamping die. This research paper can contribute some useful information to obtain fine surface finishing during

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machining die application without required polishing activities. Furthermore, the data obtained also can be used to help machinist and another researcher in the future in order to get a better surface finish, less working processing and also minimizing the operational cost.

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CHAPTER 2 LITERATURE REVIEW

2.1 Machining

Machining can be defined as the process of removing material from a work piece in the form of chips. The term metal cutting is used when the material is metallic. Most machining has very low setup cost compared to forming, molding, and casting processes. However, machining is much more expensive for high volumes. Machining is necessary where tight tolerances on dimensions and finishes are required.

This metalworking technique actually involves many types of processes that can be used to give metal the desired shape and finish. These techniques are often divided into four categories, and may be used together to produce a single product. Drilling is one of the most basic types of machining. During the drilling process, workers use a metal bit to cut holes in the metal. For example, drilling may be used to cut holes for fasteners in a metal kick plate used to protect a door.

2.1.1 Dry machining

Dry machining is ecologically desirable and it will be considered as a necessity for manufacturing enterprises in the near future. Industries will be compelled to consider dry machining to enforce environmental protection laws for occupational safety and health regulations. The advantages of dry machining include: non-pollution of the atmosphere (or water); no residue on the swarf

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which will be reacting in reduced disposal and cleaning costs; no danger to health; and it is non-injurious to skin and is allergy free. Moreover, it offers cost reduction in machining. (Narutaki et. al, 1997)

The various possible routes to achieve clean machining processes were analyzed and discussed by Byrne, 1996. Elimination of the use of cutting fluids, if possible, can be a significant incentive. The costs connected with the use of cutting fluids are estimated to be many more times than the labor and overhead costs. Hence the implementation of dry machining will reduce manufacturing costs. In the manufacturing industry, cutting fluids help to remove the heat generated due to friction during cutting to achieve better tool life, surface finish and dimensional tolerances prevent the formation of built-up edge and to facilitate the transportation of chips. Coolants are essential in the machining of materials such as aluminium alloys and most stainless steels, which tend to adhere to the tool and cause a built-up edge. At the same time, the coolants produce problems in the working environment and also create problems in waste disposal. This creates a large number of ecological problems, but which in turn result in more economical overheads for manufacturing industries. If industries were to practice dry machining, then all of the above-mentioned problems should be addressed satisfactorily. The cutting fluid industries are reformulating new composites that are more environmentally friendly and which do not contain Pb, S or Cl compounds. (Santhanakrishnan, 1994)

Consumption of cutting fluids has been reduced considerably by using mist lubrication. However, the mist in the industrial environment can have serious respiratory effects of the operation. The use of cutting fluids will be increasingly more expensive as stricter enforcement of new regulation and standards are imposed, leaving no alternative but to consider dry machining. Many metal-cutting processes have been developed and improved based on the availability of coolants. It is well known that coolants improve the tool life and tool performance to a great extent. In dry machining, there will be more friction and

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adhesion between the tool and the work piece, since they will be subjected into higher temperatures.

This will result in increased tool wear and hence reduction in tool life. Higher machining temperatures will produce ribbon-like chips and this will affect the form and dimensional accuracy of the machined surface. However, dry cutting also has some positive effects, such as reduction in thermal shock and hence improved tool life in an interrupted-cutting environment. (Sreejith and Ngoi, 1999)

2.1.2 Elements of machining

The complete machining process is composed of four elements; Fig. 2.1.

Figure 2.1: Elements of machining process (Krar and Check, 1997)

1. Workpiece – besides, it also includes prime-mover and work holding devices. 2. Tool- it also includes tool holding devices.

3. Chip and

4. Cutting Fluid

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1.2 Objective

The overall aim of this research is to study the surface integrity of FC300 cast iron. The aim can be resolved into the following specific objectives:

a) To analyze the surface integrity of FC 300 cast iron after machining based on:

i) Subsurface microstructure and ii) Subsurface microhardness

1.3 Problem Statement

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CHAPTER 2

LITERATURE REVIEW

2.1 Machining

2.1.1 Dry machining

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adhesion between the tool and the work piece, since they will be subjected into higher temperatures.

2.1.2 Elements of machining

The complete machining process is composed of four elements; Fig. 2.1.

Figure 2.1: Elements of machining process (Krar and Check, 1997)

1. Workpiece – besides, it also includes prime-mover and work holding devices. 2. Tool- it also includes tool holding devices.

3. Chip and 4. Cutting Fluid

Investigate Surface Integrity When Machining FC300 Cast Iron Using Uncoated Carbide Ball End Mill - Study Of Subsurface Micrograph.

UNIVERSITI TEKNIKAL MALAYSIA MELAKA