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UNIVERSITI TEKNIKAL MALAYSIA MELAKA
PROCESS OPTIMIZATION OF EDM CUTTING PROCESS ON
TOOL STEEL USING ZINC COATED ELECTRODE WIRE
This report submitted in accordance with requirement of the Universiti Teknikal
Malaysia Melaka (UTeM) for the Bachelor of Manufacturing Engineering Technology
(Process & Technology) with Honours
By
MUHAMMAD QAMARUDDIN BIN MOHD AHYAN
B071210458
910814-01-6793
FACULTY OF ENGINEERING TECHNOLOGY
2015
UNIVERSITI TEKNIKAL MALAYSIA MELAKA
BORANG PENGESAHAN STATUS LAPORAN PROJEK SARJANA MUDA
TAJUK: PROCESS OPTIMIZATION OF EDM CUTTING PROCESS ON TOOL
STEEL USING ZINC COATED ELECTRODE WIRE
SESI PENGAJIAN: 2015/16 Semester 1
Saya MUHAMMAD QAMARUDDIN BIN MOHD AHYAN
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:
NO. 3, JALAN DELIMA, PESERAI
KECIL, SIMPANG LIMA, 83020
BATU PAHAT, JOHOR
Tarikh: ________________________
Disahkan oleh:
(TANDATANGAN PENYELIA)
Cop Rasmi:
** Jika Laporan PSM ini SULIT atau TERHAD, sila lampirkan surat daripada pihak berkuasa/organisasi
berkenaan dengan menyatakan sekali sebab dan tempoh laporan PSM ini perlu dikelaskan sebagai
SULIT atau TERHAD.
3
Rujukan Kami (Our Ref) : Rujukan Tuan (Your Ref) :
09 DEC 2015 Pustakawan Perpustakaan UTeM Universiti Teknikal Malaysia Melaka Hang Tuah Jaya, 76100 Durian Tunggal, Melaka. Tuan/Puan, PENGKELASAN LAPORAN PSM SEBAGAI SULIT/TERHAD LAPORAN PROJEK SARJANA MUDA TEKNOLOGI KEJURUTERAAN PEMBUATAN (Process & Technology): MUHAMMAD QAMARUDDIN BIN MOHD AHYAN Sukacita dimaklumkan bahawa Laporan PSM yang tersebut di atas bertajuk “Process Optimization Of Edm Cutting Process On Tool Steel Using Zinc Coated Electrode Wire” mohon dikelaskan sebagai *SULIT / TERHAD untuk tempoh LIMA (5) tahun dari tarikh surat ini. 2. Hal ini adalah kerana IANYA MERUPAKAN PROJEK YANG DITAJA OLEH SYARIKAT LUAR DAN HASIL KAJIANNYA ADALAH SULIT. Sekian dimaklumkan. Terima kasih. Yang benar, ________________ Tandatangan dan Cop Penyelia
i
DECLARATION
I hereby, declared this report entitled “Process Optimization Of EDM Cutting
Process On Tool Steel Using Zinc Coated Electrode Wire” is the results of my own
research except as cited in references.
Signature : ………………………………………….
Name : Muhammad Qamaruddin Bin Mohd Ahyan
Date : …………………………………………
ii
APPROVAL
This report is submitted to the Faculty of Engineering Technology of UTeM as a
partial fulfillment of the requirements for the degree of Bachelor of Engineering
Technology (BETP) (Hons.). The member of the supervisory is as follow:
………………………………
(Engr Hanizam Bin Hashim)
iii
ABSTRACT
Electrical Discharge Machining (EDM) is a process of metal machining in
which a tool discharges thousands of sparks to a metal work piece. The main
purpose of this project is to compare surface roughness of tool steel material
using zinc coated brass and brass electrode wires and to recommend the best
electrode diameter to machine tool steel work piece material application. There
are three objective of this project that needs to be accomplished. Firstly is to
compare the surface roughness of tool steel material using zinc coated brass and
brass electrode wires. Secondly is to recommend the best electrode diameter to
machine tool steel work piece material application. Thirdly is to study the effects
of feed rate to the surface roughness. 3 work pieces are machining and 15
readings of surface roughness are taken for every size of diameter of wire. By
using the Minitab software, the data in each objective is done. As a conclusion,
the best wire for both types is zinc coated brass. Then, the best diameter of wire
is 0.10 mm based on their surface roughness result. Next, according to feed rate
changed, it is not much a distinction in effect of surface roughness value. In
addition, take an over reading on each sample to be a correction if have any error
occurred.
iv
ABSTRAK
Electrical Discharge Machining (EDM) adalah satu proses pemesinan logam di mana
alat yang melepaskan beribu-ribu percikan api kepada bahan kerja logam. Tujuan
utama projek ini adalah untuk membandingkan kekasaran permukaan alat bahan
ujian keluli menggunakan zink bersalut tembaga dan tembaga wayar elektrod dan
mencadangkan elektrod terbaik untuk mesin alat keluli bahan kerja. Terdapat tiga
objektif projek ini yang perlu dicapai. Pertama adalah untuk membandingkan
kekasaran permukaan alat bahan keluli menggunakan zink bersalut tembaga dan
tembaga wayar elektrod. Kedua adalah untuk mencadangkan garis pusat elektrod
terbaik untuk mesin alat keluli bahan kerja. Ketiga adalah untuk mengkaji kesan
kadar suapan untuk kekasaran permukaan. Sebanyak 3 keping bahan dan 15 bacaan
kekasaran permukaan yang diambil untuk setiap saiz diameter wayar. Dengan
menggunakan perisian Minitab, data dalam setiap objektif dilakukan.
Kesimpulannya, wayar terbaik untuk kedua-dua jenis adalah zink bersalut tembaga.
Kemudian, diameter yang terbaik wayar ialah 0.10 mm berdasarkan keputusan
kekasaran permukaan. Seterusnya, berkenaan dengan perubahan kadar suapan, ia
tidak banyak perbezaan dalam nilai kekasaran permukaan. Tambahan lagi,
mengambil bacaan yang lebih pada setiap sampel adalah untuk membuat sebarang
pembetulan jika sesuatu kesilapan berlaku.
v
DEDICATION
Firstly, dissertation is dedicated to Universiti Teknikal Malaysia Melaka, whose give
opportunity in order to complete my case study. It is very helpful with provided good
facilities and services while research happened. Secondly, I would like to dedicated
to Mr Engr. Hanizam Bin Hashim as supervisor and Mr. Mohd Kamal bin Musa as
co-supervisor whose passion for teaching set a new knowledge that can be apply, not
only in this research, also can be implement in daily routine. Other than that,
technician in Faculty of Engineering Technology (FTK) , those who always gave
good co-operation and time in order to completed this research. Lastly this dedication
to Mohd Razali Bin Md Yunos whose approved this research and improvised on how
to make this research more useful and helpful in industry.
vi
ACKNOWLEDGEMENT
By the name of ALLAH, the Most Gracious and Most Merciful
Due to completion of this thesis, I am deeply indebted to my respected
supervisor, Engr. Hanizam bin Hashim from Faculty of Engineering Technology,
University Teknikal Malaysia Melaka (UTeM) for his encouragement, motivation,
constructive criticism and beneficial guidance which led me through this project. I
would also like to express my greatest gratitude to Mr. Mohd Kamal bin Musa from
Faculty of Engineering Technology, co-supervisor of this project for his advice and
continuously guides me during performing the Wire Electric Discharge Machine
(WEDM). Special thanks to management of UTeM for the financial support
throughout this project.
Deep gratitude goes to multitude of my friends who have contributed their aid
in some manner, especially Nuraiman Bin Samli and Muhammad Nizam Bin Abd
Samat. Special thanks to my beloved father, mother and siblings for their moral
support in completing this degree. Lastly, thank you to everyone who had been to the
crucial parts of realization of this project. Only Allah S.W.T could bestow all of you
with His bless and kindness, handsomely reward for your contributions.
vii
TABLE OF CONTENTS
DECLARATION i
APPROVAL ii
ABSTRACT iii
ABSTRAK iv
DEDICATION v
ACKNOWLEDGEMENT vi
TABLE OF CONTENTS vii
LIST THE FIGURES x
LIST OF TABLES xi
LIST ABBREVIATIONS, SYMBOLS xii
CHAPTER 1 1
INTRODUCTION 1
1.1 Project Background 1
1.2 Problem Statement 3
1.3 Objective 3
1.4 Scope of the Research 3
1.5 Outline Of the Report 4
CHAPTER 2 5
LITERATURE VIEW 5
2.1 Wire Electrical Discharge Machining (WEDM) 5
viii
2.1.1 Working Principles Of WEDM 7
2.2 Wire Electrode 9
2.2.1 Zinc Coated Brass Wire Electrode 9
2.3.1 Brass Wire Electrode 10
2.3 Tool (Electrode) 11
2.4 Influence Of Process Parameters On The Wire EDM Process 12
2.5 Surface Integrity 13
2.6 Kerf 13
2.6.1 Kerf In WEDM 15
2.7 Statistical Analysis 15
2.8 T-Test 16
CHAPTER 3 17
METHODOLOGY 17
3.1 Project Planning (Flow Chart) 17
3.2 Material Selection 19
3.2.1 AISI H13 Material 19
3.3 Wire Electrodes 20
3.3.1 Zinc Coated Brass 20
3.3.2 Brass 21
3.4 Wire Electrical Discharge Machining 22
3.4.1 Parameter 24
3.5 Surface Roughness Tester Mitutoyo SJ-410 25
3.5.1 Standard Procedure for Surface Roughness Testing 26
3.6 Part To Be Cut 28
3.7 Data Collection 29
3.8 Wire-cut Electrical Discharge Machining (WEDM) Procedure 30
CHAPTER 4 31
ix
RESULTS & DISCUSSION 31
4.1 Comparison Between Brass And Zinc Coated Electrode Wire 31
4.2 Comparison Between Different Diameter Of Zinc Coated Eletrode Wire 35
4.3 The Effects Of Feed Rate To Surface Roughness Data Collection 38
4.3.1 Analysis For 0.7 Against 1.1 41
4.3.2 Analysis For 0.9 Against 1.1 42
4.3.3 Analysis For 0.7 Against 0.9 43
CHAPTER 5 44
CONCLUSION & FUTURE WORK 44
5.1 Summary Of Research 44
5.2 Future Work 45
APPENDICES 47
APPENDIX A 48
EQUIPMENTS 48
APPENDIX B 50
WORK PIECE 50
BIBLIOGRAPHY 53
x
LIST THE FIGURES
Figure 2.1 : Wire Driving And Cutting Mechanism In Wedm 6
Figure 2.2 : Schematic For WEDM Process 7
Figure 2.3 : Schematic Diagram For WEDM 7
Figure 2.4 : The Movement Of Electrode Wire Against Work Piece 8
Figure 2.5 : Pure Zinc Coating On Brass Wire Core 10
Figure 2.6 : Plain Brass 11
Figure 2.7 : Factors Influencing The Wire Edm Process 12
Figure 2.8 : Schematic Of The Work Piece And The Process 14
Figure 2.9 : Details Of Kerf Width 14
Figure 3.1 : Research Development Process Flow 18
Figure 3.2 : Mild Steel Plates 20
Figure 3.3 : Zinc Coated Brass Electrode Wire 21
Figure 3.4 : Brass electrode wire 22
Figure 3.5 : Wire Electrical Discharge Machining (Wedm) Sodick Vz300l 24
Figure 3.6 : Mitutoyo Surface Roughness Tester 25
Figure 3.7 : Illustration of application of Surface Roughness Tester 26 Figure 3.8 : Drawing path to be cut 28
Figure 4.1 : Brass Against Zinc Coated 33
Figure 4.2 : Interval Plot For Diameter Wire 37
Figure 4.3 : Time Series Plot For Different Feed Rate 39
Figure 4.4 : A Boxplot For The Feed Rate Of The Wire Electrode 39
Figure 4.5 : 2-Sample T-Test For The Mean Of 0.7 And 1.1 41
Figure 4.6 : 2-Sample T-Test For The Mean Of 0.9 And 1.1 42
Figure 4.7 : 2-Sample T-Test For The Mean Of 0.7 And 0.9 43
xi
LIST OF TABLES
Table 3.1 : Physical Properties Of Tool Steel 19
Table 3.2 : Specification Of Zinc Coated Brass 21
Table 3.3 : Specification of Brass Electrode 22
Table 3.4 : Specification of Sodick VZ300L WEDM 23
Table 3.5 : Parameter during machining process 24
Table 3.6 : Specification Of Surface Roughness Tester 25
Table 3.7 : Procedure of using Mitutoyo Surface Roughness Tester 27
Table 3.8 : Table Of Experiment 29
Table 3.9 : Step By Step Of WEDM Operation Setup 30
Table 4.1 : Surface Roughness For Both Of The Wire 32
Table 4.2 : Minitab Result For Two-Sample T 34
Table 4.3 : Surface Roughness For Different Diameter 36
Table 4.4 : Surface Roughness For The Different Of Feed Rate 38
xii
LIST ABBREVIATIONS, SYMBOLS
ANOM = Analysis Of Means
CNC = Computer Numerical Control
EDM = Electrical Discharge Machine
H0 = Null Hypothesis
MRR = Material Removal Rate
Nc = Numerical Control
Ra = Surface Roughness
WEDM = Wire Electrical Discharge Machining
1
CHAPTER 1
INTRODUCTION
This chapter basically explains the background, problem statement, objectives
and scope on research.
1.1 Project Background
Electrical Discharge Machining (EDM) is a process of metal machining in
which a tool discharges thousands of sparks to a metal work piece. A non-
conventional process, EDM melts or vaporizes cutting material, leaving little
debris and providing a very accurate line. Industry-wide acceptance has led to a
wide variety of EDM applications, as it is highly versatile, can cut hard metals,
and utilizes a relatively compact amount of workspace.
According to this experiment process, there are some info on electrode
material used at the industry such as brass, copper, silver etc. As an information,
Brass was one of the first EDM electrode materials. It is inexpensive and easy to
machine but it exhibits a higher degree of stiffness and is easier to machine than
Copper. Besides, Copper became the metallic electrode material of choice
because of the combination of Copper and certain power supply settings enables
low wear burning. This electrode material still has a significant disadvantages, it
is soft and gummy material to machine or grind. Then, Silver occasionally due to
2
its superior electrical conductivity, purity and structural integrity. However, due
to the cost, Silver is rare to be used. (Kern, 2008)
Based on this project title, the main electrode material is zinc coated wire.
It is consists of brass wire electroplated with high purity zinc. The high plating
accuracy realizes faster machining speed and also provides a better surface finish
on the work piece. The high purity zinc layer formed on the surface of the brass
by means of our unique electroplating technology realizes higher machining
speed.
By uniformly coating the surface of the wire with zinc, which has good
discharge characteristics, it is possible to create a finer discharge compared to
when using general brass wire. In the finishing process, improved surface
roughness and a better machined profile are obtained, resulting in high cost
performance. Almost no copper adheres to the work piece. The zinc coating
method is a method of coating by electroplating. It is not a method in which is
wire is dipped in molten zinc. A high purity uniform zinc layer can be obtained.
The discharge is stable and free of irregularities. Impurities are kept to the
minimum, thus preventing deterioration of performance. (Cable, 2012)
This project is conducted to optimize process of EDM cutting on tool
steel using zinc coated electrode wire. Other than that, this project also to study
about zinc coated on brass wire on EDM cutting process. Then, this analysis will
find out the parameter by using proper current, speed travelling and diameter of
zinc coated electrode wire.
3
1.2 Problem Statement
Lately, Brass wire electrode been used in the industry for quite
sometimes because its offer low cost and good quality finishing. in recent years,
zinc coated brass offer higher cutting speed and performance. (Mms, 2015)
However, study in this matter is still insufficient to prove zinc coated brass is
better than brass.
1.3 Objective
Based on this problem, the type of wire to be testing is zinc coated brass
electrode wire. In addition, this is the objective below:
1. To compare surface roughness of tool steel material using zinc coated brass
and brass electrode wires.
2. To recommend the best electrode diameter to machine tool steel work piece
material application.
3. To study the effects of feed rate to surface roughness.
1.4 Scope of the Research
The work scope that will involve in this project is the type of wire cut
involved is brass and zinc coated brass. To make sure that these will be achieved, the
machine of EDM that will be use is Sodick VZ300L. Furthermore, the diameter of
the wire electrode is 0.1 mm, 0.2 mm and 0.25 mm. The type of material to be cut or
use on this study is tool steel AISI H13. The surface roughness of the material cut
will be measured using Mitutoyo SJ-410. At the end of this experiment analysis, the
application of EDM will know as much and the diameter of wire electrode of EDM
wire cut by zinc coated will be found.
4
1.5 Outline Of the Report
This project has been divided into five chapters covering the whole our culture in
order to achieve the desired objectives. The contents of each chapter have been
decided after the information was found. The included content is based on
discussions with the supervisor and the information obtained from previous research.
Chapter 1 explains about the project background. Then it followed by objectives of
the project, problem statements and scope of the project. Finally, in this chapter
explain the outline of the project.
Chapter 2 shows the literature review about the previous work on the wire cut EDM
machine. These previous study works as a guidance to perform or build the idea to
solve the problems later.
Chapter 3 explains the methodology used in order to solve the problem.
Methodology is important because the working progress followed the methodology
step and makes it achieve the objective or not.
Chapter 4 explains procedures, results and discussion made after completion of the
work done in the lab. All prove of the action that be done need to state in this chapter
and attached with the explanation of the action.
Chapter 5 shows the conclusion and recommendation of the project. The conclusion
made is based on the findings that get from the action that had been done. Based on
what already done, suggestion about another material is stated here in order to go
further on this project in future.
5
CHAPTER 2
LITERATURE VIEW
This chapter basically explains about machinery and equipment used in this project
as a guide for studies. Besides, basic information about Wire Electrical Discharge
Machining (WEDM) will be tell and how to operate the machine. At early stage of
the studies, some gap analysis has been carried out in order to ensure the relevance of
this research. All relevant aspect such as current, speed travelling and diameter of
electrode wire will be told a little bit in this chapter.`
2.1 Wire Electrical Discharge Machining (WEDM)
The introduction of continuous Wire-EDM to industrial practice in 1969
revolutionised the manufacture of punching, pressing and extrusion tools, and rapidly
led to its achieving a monopoly. The process has also gained acceptance in prototype
production and in series production e.g. for the aerospace industry. In the Wire-EDM
process, the material is removed by means of temporally and spatially discrete
discharges which produce local vaporization and melting in association with ejection
processes. This enables all electrically-conductive materials to be processed without
significant exertion of force, irrespective of their hardness.
Continuous Wire-EDM cutting comprises two successive processing steps. A
main cut (high discharge energy) is carried out first, in order to cut out the desired
6
geometry from the solid material as rapidly as possible, with an allowance for the
secondary cuts. Accuracy and surface quality are still unsatisfactory after the main
cut. The discharge energy is then gradually reduced during a series of 1-7 secondary
cuts, to obtain high accuracy and good surfaces quality.
A volume of work piece has been removed during this short period of spark
discharge depends on the desired cutting speed and the surface finish required.
Estimated at around 15000 to 21000 Fahrenheit to heat of each electrical spark and
erode away a bit of material that is vaporized and melted from the work piece. The
chips are flushed away from the cut with a stream of deionised water through the top
and bottom flushing nozzles. The heat build-up in the work piece is prevented by
deionised water. (Moulton, 2015). Without this cooling system, thermal expansion of
the work piece would affect size and positioning accuracy.
Figure 2.1 : Wire driving and cutting mechanism in WEDM, Source : (W,
2011)
7
Figure 2.2 : Schematic for WEDM process (Roger, 2014)
Figure 2.3 : Schematic Diagram For WEDM, (Patnaik, 2006)
2.1.1 Working Principles Of WEDM
Wire Electrical Discharge Machining (WEDM) is non–traditional machining
techniques that have high accuracy although complicated shapes especially for the
parts that are difficult to be machined. From WEDM can make tools and dies and is
an alternative of producing small scale parts with the great dimensional accuracy and
surface finish quality. In WEDM, wire is used as electrode that made of thin copper,
8
brass or tungsten that have diameter 0.05 mm until 0.3 mm which is capable of
achieving very small radius of corner. By using mechanical tensioning device, the
wire is kept in tension and can reduce to produce inaccurate parts. (Sathiaraj, 2015).
In WEDM, the conductive materials are machined with electrical discharging
that will produce sparks between an accurately positioned of electrode wire and the
work piece. According to (Cable, 2012), the high frequency pulses of alternating or
direct current is discharged from the electrode wire with a small gap or spark through
a dielectric fluid. Sparks can be observed and the actual discharging occur more than
one hundred thousand times per second and lasting in the range of 1/1000000 of a
second or less.
A volume of work piece has been removed during this short period of spark
discharge depends on the desired cutting speed and the surface finish required.
Estimated at around 15000 to 21000 Fahrenheit to heat of each electrical spark and
erode away a bit of material that is vaporized and melted from the work piece.
(Moulton, 2015). The chips are flushed away from the cut with a stream of deionised
water through the top and bottom flushing nozzles. The heat build-up in the work
piece is prevented by deionised water. (Edge, 2015). Without this cooling system,
thermal expansion of the work piece would affect size and positioning accuracy.
Figure 2.4 : The movement of electrode wire against work piece,
Source: (Edge, 2015)
9
2.2 Wire Electrode
A variation of EDM is WEDM or electrical discharge wire cutting. In
WEDM process, this almost similar to contour cutting with a band saw. The wire
travels slowly along a prescribed path and the work piece is cutting with discharge
sparks. The wire can cut a work piece as thick as 300 mm and usually being used to
make a mould, punches, tool and dies from hard metal. Intricate components for the
electronics industries also will be cut. According to (Wukesha, 2014) accessed on 5
May 2014, WEDM is a machine to cut material with a slight wire anode that takes
after a customized way. The wires are generally made of metal, copper or tungsten.
Zinc or metal covered wires are additionally being utilized. The wire diameter is
typically about 0.30 mm for roughing cut and 0.20 mm for finishing cut.
There is no effect on cutting speed even the work piece material is hardness
and no physical contact between the wire and part being machined. The important
factors in selecting brass and copper are ability to generate an electric discharge,
mechanical strength at high temperature, high electrical conductivity and high heat
conductivity. The wire also should have sufficient tensile strength and fracture
toughness as well as high electrical conductivity and capacity to flush away the
debris produces during the cutting. (Wukesha, 2014)
2.2.1 Zinc Coated Brass Wire Electrode
At the Figure 2.5 below shows the structure of Pure Zinc Coated on Brass
Wire Core. The brass wire is coated with 100% zinc although the brass contain a
little of zinc.