Investigation Of Tool Wear Characteristics For Numerical Control Sculpture (NCS) Machine.
INVESTIGATION OF TOOL WEAR CHARACTERISTICS
FOR NUMERICAL CONTROL SCULPTURE (NCS)
MACHINE
MUHAMMAD JABIR B. SULEIMAN @ AHMAD
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UNIVERSITI TEKNIKAL MALAYSIA MELAKA
Investigation of Tool Wear Characteristics for
Numerical Control Sculpture (NCS) Machine
Thesis submitted in accordance with the requirements of the Universiti Teknikal Malaysia Melaka for the Degree of Bachelor of Engineering (Honours)
Manufacturing (Design)
By
Muhammad Jabir B. Suleiman @ Ahmad
Faculty of Manufacturing Engineering May 2007
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UTeM Library (Pind.1/2005)
UNIVERSITI TEKNIKAL MALAYSIA MELAKA (UTeM)
BORANG PENGESAHAN STATUS TESIS*
JUDUL: INVESTIGATION OF TOOL WEAR CHARACTERISTICS FOR NUMERICAL CONTROL SCULPTURE (NCS) MACHINE
SESI PENGAJIAN: 2006/ 2007
Saya MUHAMMAD JABIR B. SULEIMAN @ AHMAD
mengaku membenarkan t esis (PSM/ Sarj ana/ Dokt or Falsaf ah) ini disimpan di Perpust akaan Universit i Teknikal Malaysia Melaka (UTeM) dengan syarat -syarat kegunaan sepert i berikut :
1. Tesis adalah hak milik Universit i Teknikal Malaysia Melaka.
2. Perpust akaan Universit i Teknikal Malaysia Melaka dibenarkan membuat salinan unt uk t uj uan pengaj ian sahaj a.
3. Perpust akaan dibenarkan membuat salinan t esis ini sebagai bahan pert ukaran ant ara inst it usi pengaj ian t inggi.
4. **Sila t andakan (√) SULIT
TERHAD
TIDAK TERHAD
(Mengandungi maklumat yang berdarj ah keselamat an at au kepent ingan Malaysia yang t ermakt ub di dalam AKTA RAHSIA RASMI 1972)
(Mengandungi maklumat TERHAD yang t elah dit ent ukan oleh organisasi/ badan di mana penyelidikan dij alankan)
(TANDATANGAN PENULIS) Alamat Tet ap:
No. 141-H, Bat u 19 ¼, 77 000 Jasin,
Melaka Tarikh: Disahkan oleh: (TANDATANGAN PENYELIA) Cop Rasmi: Tarikh:
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APPROVAL
This thesis submitted to the senate of UTeM and has been accepted as partial fulfillment of the requirements for the degree of Bachelor of Manufacturing Engineering (Manufacturing Design). The members of the supervisory committee are as follow:
………. Main Supervisor
(Official Stamp & Date)
……….. Co-Supervisor
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DECLARATION
I hereby, declare this thesis entitled “Investigation of Tool Wear Characteristics for Numerical Control Sculpture (NCS) Machine” is the results of my own research except
as cited in the reference.
Signature : ………
Author’s Name : ………
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i
ABSTRACT
This paper presented an investigation of tool wear characteristic based on the machining process on Numerical Control Sculpture (NCS) machine. Typically time is the major parameter or indicator being used in measuring the progress of machine capability. The technicians in Fujitsu Component (M) Sdn. Bhd. approximately indicated that the maximum wear occurred on cutting tool during 2 hours of machining time. But in certain cases, there are cutting processes than can run more than 2 hours without changing the wear cutting tool with the new one. For that matter, the factors that can contribute to the wear phenomena are the machining parameters, machining condition, type of cutter, machining material and the shape of work material are investigate. Referring to the technician’s assumption, so there are 4 different gaps of time have been chosen beginning from 35 minutes, 70 minutes, 105 minutes and 140 minutes. Instead of checking the cutting tool life, the surface quality of the work material will also be analyzed based on surface roughness measurement as affected from 2 types of cutting tool from different material properties. Entirely this investigation consists of 32 pieces of cutting tool from different shape and material, and 32 pieces of work material from 2 different type of material, Copper Tungsten and Mild Steel SS 41. The obtain results shows the wear mechanism occurred earlier during 105 minutes, less than expected and become more critically when it reached to 140 minute or greater than 2 hours. Additionally, Carbide proved to be the most hardest and high quality cutting tool rather than High Speed Steel (HSS). The overall result have shown that after 2 hours of cutting time, the cutting tool should be replaced with the proper and appropriate one as to match with the required cutting conditions and parameters.
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ABSTRAK
Tesis ini mendedahkan kajian berkenaan sifat – sifat perkakas pemotongan berdasarkan proses pemesinan yang dijalankan menggunakan mesin Numerical Control Sculpture (NCS). Secara amnya, masa adalah merupakan parameter utama yang biasa digunakan bagi mengukur tahap kemampuan sesuatu mesin. Juruteknik di Fujitsu Component (M) Sdn. Bhd. menganggarkan bahawa kadar kehausan maksimum ke atas perkakas pemotongan berlaku dalam tempoh 2 jam masa pemesinan. Walaubagaimanapun dalam sesetengah kes, terdapat proses pemotongan yang boleh berlangsung lebih daripada 2 jam tanpa perlu penggantian perkakas pemotongan yang tumpul kepada yang baru. Disebabkan perkara itu, beberapa faktor yang menyumbang kepada berlakunya fenomena kehausan seperti parameter pemesinan, keadaan pemesinan, jenis – jenis perkakas pemotongan, bahan kerja dan bentuk bahan yang dimesin juga dikaji. Berdasarkan anggaran juruteknik tersebut, maka terdapat 4 jarak masa yang telah dipilih bermula daripada 35 minit, 70 minit, 105 minit dan 140 minit. Selain kajian terhadap kadar kualiti perkakas pemotongan, kualiti permukaan bahan kerja juga dianalisis berdasarkan pengukuran kekasaran pada permukaan kesan dari 2 jenis perkakas yang berlainan kandungan bahannya. Secara keseluruhan kajian ini melibatkan 32 jenis perkakas pemotongan yang terdiri dari 2 jenis bahan yang berbeza, dan 32 bahan kerja yang juga terdiri dari 2 jenis bahan yang berbeza iaitu Copper Tungsten dan Mild Steel SS 41. Keputusan yang diperolehi menunjukkan mekanisma kehausan berlaku awal ketika minit ke 105 iaitu kurang dari jangkaan dan menjadi lebih kritikal apabila mencapai 140 minit atau lebih dari 2 jam. Sebagai tambahan, dapat dibuktikan Carbide adalah perkakas pemotongan yang paling keras serta berkualiti berbanding dengan High Speed Steel (HSS). Keseluruhannya, perkakas pemotongan perlu diganti baru selepas 2 jam masa pemesinan bersesuaian dengan keadaan serta parameter ketika pemotongan.
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DEDICATION
For my beloved Father and Mother who always encourage and give all the support that I really need during accomplish this thesis.
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ACKNOWLEDGEMENTS
I wish to acknowledge and express my gratitude and appreciation to (i) my supervisor, Mr. Hadzley b. Abu Bakar for his supervision, encouragement, suggestion and assistance through the research; (ii) my parents, Mr. Suleiman b. Hj. Ghazali and Madam Sutinah bt. Hj. Abdullah whose constant encouragement, faith and confidence besides continuously moral support; (iii) Mr. Nor Azizan b. Ahmad, the manager of Tooling section in Part Production Department from Fujitsu Component (M) Sdn. Bhd. for the permission and ample opportunity to facilitate fruitful case study and last but not least (iv) Mr. Amri b. Sulaiman, being my co-supervisor for his full encouragement besides significant contribution in proof reading the manuscript were tremendous contribution.
It is a pleasure for me to express huge gratitude to Mr. Rosni b. Amad Sulaiman and Mr. Mat Robi @ Mohd. Nazri b. Mohd. Ali, the technical staff who construct and guide through completing this research while conducting the machining process in FCM as his kindness and willing really regards me with pleasure. Similar gratitude also goes to Fujitsu Component (M) Sdn. Bhd. for the research grant; and the greatest thanks should be goes to all individuals and colleagues who have contribute so much throughout my study. I could offer here only an inadequate gesture of my appreciation and all of your good deeds will always be in my mind.
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v
TABLE OF CONTENT
Abstract ...i
Dedication ...iii
Acknowledgement ...iv
Table of Contents ...v
List of Figures ...ix
List of Table ...xiii
List of Abbreviations, Symbols and Specialized Nomenclature ...xiv
1. INTRODUCTION ...1
1.1 Background ...1
1.2 Problems Statements ...2
1.3 Objectives of the Research ...3
2. LITERATURE REVIEW ...5
2.1 Cutting Tool ...5
2.1.1 Cutting Tool Material ...7
2.1.1.1 High Speed Steels ...7
2.1.1.2 Carbides or Sintered Carbides ...9
2.1.2 Cutting Tool Criteria ...10
2.1.3 End Mill Technical Features ...13
2.2 Milling ...18
2.2.1 Fundamentals of Milling Processes ...20
2.2.2 Choosing the Process ...20
2.2.3 Tool Selection ...21
2.2.4 Controlling Heat Generation ...23
2.2.5 Tool Issues ...26
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2.2.7 Programming ...28
2.3 Work Material ...29
2.3.1 Copper Tungsten ...30
2.3.1.1 Copper ...30
2.3.1.1.1 Applications ...32
2.3.1.1.2 Structure ...32
2.3.1.1.3 Key Properties of Copper Alloys ...32
2.3.1.1.4 Copper Designation ...35
2.3.1.1.5 Other Alloy Groups ...37
2.3.1.2 Tungsten ...38
2.3.1.2.1 Key Properties ...39
2.3.1.2.2 Applications ...39
2.3.2 Mild Steel – SS 41...40
3. METHODOLOGY ...42
3.1 Introduction ...42
3.2 Project Selection ...44
3.3 Studying the Matter Relates ...45
3.4 List and Choose the Parameter ...46
3.4.1 Cutting Tool ...47
3.4.2 Work Material ...48
3.4.3 Cutting Feed ...48
3.4.4 Cutting Speed ...48
3.4.5 Depth of Cut ...49
3.4.6 Cutting Condition ...49
3.5 Design and Generate NC Program of Work Material ...50
3.5.1 Designing the Work Material ...50
3.5.2 Generate NC Program ...52
3.6 Machining Process on NCS Machine ...57
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vii
3.7.1 Analysis on Cutting Tool ...61
3.7.2 Analysis on Work Material ...62
3.8 Conclusion of the Experiment ...63
4. RESULT...………...64
4.1 Tool Wear Based on S.E.M Figure……….64
4.1.1 Flank Wear based on Side Cutting Edges………..65
4.1.2 Central Wear based on Centre Cutting Edges………67
4.1.3 Tool Wear from Different Type of End Mill……….68
4.2 Surface Roughness of Work Material……….69
4.2.1 Roughness Average (Ra) from Different Type of Work Material………….69
4.2.2 Roughness Average (Ra) from Different Type of End Mill………..71
4.3 S.E.M. Figure………..72
4.3.1 The Overall View of Cutting Tools According to Copper Tungsten………72
4.3.2 The Overall View of Cutting Tools According to Mild Steel SS 41……….77
4.3.3 The Overall View of Work Material………..82
5. DISCUSSION……….85
5.1 Introduction……….85
5.2 Tool Wear Analysis……….86
5.2.1 Tool Wear during Machining on Copper Tungsten………...87
5.2.2 Tool Wear during Machining on Mild Steel SS 41………88
5.2.3 Tool Wear between Ball Mill Cutting Tools……….90
5.2.4 Tool Wear between Flat Mill Cutting Tools……….93
5.3 Surface Roughness (Ra) Analysis on Work Material……….96
5.3.1 Surface Roughness according to Ra Value on Copper Tungsten…………..97
5.3.2 Surface Roughness according to Ra Value on Mild Steel SS 41…………...99
5.3.3 Surface Roughness between Ball Mill Cutting Tools………..101
5.3.4 Surface Roughness between Flat Mill Cutting Tools………..103
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5.4.1 Wear Performance Analysis According to Copper Tungsten………..106
5.4.2 Wear Performance Analysis According to Mild Steel SS 41………...109
5.4.3 Wear Performance Analysis According to Ball Mill Cutting Tool………..111
5.4.4 Wear Performance Analysis According to Flat Mill Cutting Tool………..116
6. SUMMARY AND CONCLUSION……….119
6.1 Conclusion……….119
6.1.1 Machining Aspects………...120
6.2 Recommendations……….122
REFERENCES ...123
APPENDICES
A Research paper
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LIST OF FIGURES
2.1a Geometrical Features of End Mill ...11
2.1b Geometrical Features of 4 Flutes End Mill ...12
2.1c Geometrical Features of End Mill ...14
2.1d Geometrical Features of End Mill ...14
2.1e Nomenclature of 4 Flutes End Mill ...16
2.1f Geometrical Features of End Mill ...17
2.2 Milling process on job part ...18
2.3a The three basic designs of cutters are ball end, corner radius (ballnose) and square end ...21
2.3b The stronger tool is modified with an angled neck for clearance ...22
2.3c The weaker tool is modified with a neck for doing straight walls ...22
2.4 Radial step-over distance for roughing and semi-finishing with a ball end mill .23 2.5 Heat generation at the cutting edge ...24
2.6 When a cutter is worn, the increased force and heat is evident in a red glow at the tip of the cutter ...25
2.7 The axial depth is critical to the HSM process ...26
2.8 Copper Tungsten material ...31
2.9 Mild Steel material ...40
3.1 Flow Chart ...42
3.2 Fujitsu Component (M) Sdn. Bhd ...43
3.3 End Mill Cutting Tool ...47
3.4 Design Using I-Deas Program ...50
3.5 The Shape of Work Material ...51
3.6 The Shape of Keytop Electrode ...51
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3.7b Selection of Finishing Process ...53
3.7c Selection of Starting Point Area ...54
3.7d Selection of Cutting Tool ...54
3.7e Set the Clearance Position of Cutting Tool ...55
3.7f Selection of Cutting Direction and Cutting Flow ...56
3.7g Generate NC Program ...56
3.8a Raw material with tool holder on vise clamp ...57
3.8b Dial Tester Indicator (DTI) ...58
3.8c Find the Machine Position of Raw Material ...58
3.8d Set the DTI Pointer ...59
3.8e Set the Machine Position, Parameters and NC Program on the Machine Controller Screen ...60
3.8f The Machining Process ...60
3.9 The EVO 50® Series Scanning Electron Microscope ...61
3.10 SEM Diagram ...62
3.11 The Surface Roughness Tester ...63
4.1 The graph of Tool Wear on work material Copper Tungsten ...65
4.2 The graph of Tool Wear on work material Mild Steel SS 41 ...66
4.3 The graph of Tool Wear on Ball End Mill based on Central Wear ...67
4.4 The graph of Tool Wear on Ball End Mill on work material ...68
4.5 The graph of Tool Wear on Flat End Mill on work material ...68
4.6 The graph of Surface Roughness (Ra) on work material Copper Tungsten ...69
4.7 The graph of Surface Roughness (Ra) on work material Mild Steel SS 41 ...70
4.8 The graph of Surface Roughness (Ra) on Ball End Mill on work material ...71
4.9 The graph of Surface Roughness (Ra) on Flat End Mill on work material ...72
4.10 S.E.M. Figure of Ball Cutter Carbide ...73
4.11 S.E.M. Figure of Ball Cutter HSS ...74
4.12 S.E.M. Figure of Flat Cutter Carbide ...75
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4.14 S.E.M. Figure of Ball Cutter Carbide ...78
4.15 S.E.M. Figure of Ball Cutter HSS ...79
4.16 S.E.M. Figure of Flat Cutter Carbide ...80
4.17 S.E.M. Figure of Flat Cutter HSS ...81
4.18 S.E.M. Figure of Copper Tungsten work material ...83
4.19 S.E.M. Figure of Mild Steel SS 41 work material ...84
5.1 Tool wears types as basic for the determination of tool life for Ball Mill and Flat Mill ...86
5.2 Photographs of Tool Wear on cutting tool during machining on Copper Tungsten at 140 minute of cutting time ...87
5.3 Photographs of Tool Wear on cutting tool during machining on Mild Steel SS 41 at 140 minute of cutting time ...89
5.4 Photographs of flank wear of Ball Mill HSS during machining on Copper Tungsten in relation to cutting time ...90
5.5 Photographs of the central wear of Ball Mill in relation to cutting time ...91
5.6 Photographs of the flank wear of Flat Mill HSS during machining on Copper Tungsten in relation to cutting time ...93
5.7 (a) Hardness of various cutting-tool materials as a function of temperature (b) Range of properties of various groups of materials ...95
5.8 Surface Roughness Tester ...96
5.9 Images of the surface roughness on work material Copper Tungsten at 140 minute of cutting time ...98
5.10 Images of the surface roughness on work material Mild Steel SS 41 at 140 minute of cutting time ...99
5.11 Measure the Ra value on work material using Surface Roughness Tester ...100
5.12 Photographs of the surface roughness of Ball Mill HSS during machining on Copper Tungsten in relation to cutting time ...101
5.13 Photographs of the surface roughness of Flat Mill HSS during machining on Copper Tungsten in relation to cutting time ...103
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5.14 Scanning Electron Microscope (S.E.M) ...105 5.15 Capturing images of specimens on Scanning Electron Microscope (S.E.M) ....105 5.16 Comparison image between (a) Flat Mill HSS and (b) Ball Mill Carbide
during 140 minute of cutting time ...106 5.17 Comparison image of Ball End Mill on Copper Tungsten work material
from different gaps of time ...107 5.18 Flow Chart of Cutting Tool with Accordance to Ra value ...108 5.19 Comparison image of Flat End Mill on Mild Steel work material
from different gaps of time ...110 5.20 Image taken from left view of (a) Ball Cutter HSS and (b) Ball Cutter
Carbide during cutting time 140 minute for work material Copper Tungsten ..111 5.21 Ball End Mill installed on round plate to put in S.E.M. (top view) ...112 5.22 Ball End Mill installed on round plate to put in S.E.M. (front view) ...112 5.23 Image taken from centre view of (a) Ball Cutter HSS and (b) Ball Cutter
Carbide during cutting time 140 minute
for work material Copper Tungsten ...113 5.24 Image taken from left view of (a) Ball Cutter HSS and (b) Ball Cutter
Carbide during cutting time 140 minute
for work material Mild Steel SS 41 ...114 5.25 Image taken from centre view of (a) Ball Cutter HSS and (b) Ball Cutter
Carbide during cutting time 140 minute
for work material Mild Steel SS 41 ...115 5.26 Image taken from left view of (a) Flat Cutter HSS and (b) Flat Cutter
Carbide during cutting time 140 minute
for work material Copper Tungsten ...116 5.27 Image taken from left view of (a) Flat Cutter HSS and (b) Flat Cutter
Carbide during cutting time 140 minute
for work material Mild Steel SS 41 ...117 5.28 Flat End Mill installed on round plate to put in S.E.M. (top view) ...118 5.29 Flat End Mill installed on round plate to put in S.E.M. (front view) ...118
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LIST OF TABLES
2.1 Recommended Chips Loads for Ball End Tool ...25
2.2 Recommended Roughing and Semi-Finishing Rpm for Ball End Tools ...27
2.3 Recommended Finishing Rpm for Ball End Tools ...29
2.4 UNS Designation ...36
3.1 Machining Parameters ...45
4.1 The values of Tool Wear on work material Copper Tungsten ...65
4.2 The values of Tool Wear on work material Mild Steel SS 41 ...66
4.3 The values of Tool Wear on Ball End Mill based on Central Wear ...67
4.4 The values of Roughness Average (Ra) on Copper Tungsten work material ...69
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LIST OF ABBREVIATIONS, SYMBOLS, SPECIALIZED
NOMENCLATURE
NCS - Numerical Control Sculpture machine FCM - Fujitsu Component (M) Sdn. Bhd. SEM - Scanning Electron Microscope SS 41 - Material Code for Mild Steel
HSS - High Speed Steel
NC - Numerical Control
CBN - Cubic Boron Nitride
EDM - Electric Discharge Machine
CNC - Computer Numerical Control machine
CAD - Computer Aided Design
CAM - Computer Aided Manufacturing DTI - Dial Tester Indicator
µm - Micrometer
Ra - Roughness Average @ Arithmetic Average
rpm - Revolution per minute
mm - Millimeter
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1
CHAPTER 1
INTRODUCTION
1.1 Background
Nowadays there are so many types of cutting tool in the market all around the world. In the past few years, only certain cutting tool that exists in the catalogue of tool manufacturers with the similar name of cutting tool like flat cutter or ball cutter. But these days, more than 10 or even hundreds cutter with the name flat cutter in front of it, have so much with its various shape, consists differ material and for sure with so much variety in its application. This situation comes consistent with the daily improvement from all the tool manufacturers in the metalworking industry as the machines technology always comes forward very fast and all the machining process has to be done in time with absolutely high quality in its product.
In this case, a whole lot more can be seen especially when it is related with manufacturing of cutting tool in globally. Each and every cutting tool that has been developed must has its specific applications. As it always correlated with the shape of material that has to be cut, type of the material, cutting conditions, cutting parameters and cutting process itself, as usual are divide into two processes, roughing and finishing. When a tool change is needed or anticipated, a performance comparison should be made before selecting the right tool for the job and in this case the phrase “the most expensive tool is always the best tool” should be considerate more. The best tool is the one that has been carefully chosen to get the job done quickly, efficiently and economically.
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1.2 Problem Statements
Wear phenomena has always been a nightmare in the industrial environment, especially when it involved with machining process as it absolutely affecting the quality of a part. In the present days, with so many modern and high technologies machines are developed everyday, mostly every part product are machined by a high technology machine and running the whole cutting process without being observed by a human being. In that matter, if once the wear occurred on the cutting tool, the technicians won’t realize it until the whole process is completely done. The consequences from this incident, is it will cause a mess of the quality surface material and the most bad news is, it won’t obtain the exact and accurate dimensions, yet far from the part tolerances.
As getting inspirational from this kind of situations, this paper are consists research of this wear mechanism and in the mean time includes the investigation of wear characteristics on cutting tool that emerge on a high technology and NC type machine. This machining experimentation is carried out using a CNC Milling machine or its original name is Numerical Control Sculpture (NCS) machine. Moreover, this machine runs based on NC program, have the ability to cuts various shapes on a material and can runs in a longer period of time. The NC programmer is developed based on design of the material shape that are adapt from EDM electrode of Keytop using a CAD/CAM program called I-Deas.
This collaboration project is held with the company that produces computer and electronic components; keyboard for desktop computer and laptop, mouse and relay. Fujitsu Component (M) Sdn. Bhd. is a very well known company especially in the quality of its product and great reception from all customers all over the world. The products from this company are among the highest choice from customers as Fujitsu have already built their names long enough. Besides that, the company has been certified with ISO 9001, QS 9000 and ISO 14001. All the staffs here are committed to their work, very innovative and professional worker and have a very good teamwork between staff.
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3
1.3 Objectives of the Research
The main objective of this research is to investigate optimum parameter for NCS:
a) Tool life (machining time capabilities before maximum wear)
According to Mr. Rosni b. Sulaiman (technician incharge of machines in 3rd process room) approximately maximum tool wear occurred at 2 hours machining duration in usual machining process. But in details there is still no clear description whether on that time, maximum tool wear really occurred or not. For that matter, this research paper is developed to investigate the characteristic of tool wear according to cutting time transition. The experiment will be conducted using Scanning Electron Microscope (SEM) in Metrology Lab in UTeM.
b) Surface quality according to the cutting time and tool wear.
On the same time, the visual of surface machined also can be investigate according to the cutting time based on the effects of the cutting process between the cutting tool and the machining material. From here, the differences can be seen between the wear cutting tool and the good one.
Other objectives of the experiment to be achieved are:
a) To determine the main reason that causing the wear to occurred on the cutting tool during machining process.
b) To explore the characteristics and properties of material used in each cutting tool, including the work material.
c) To know the exact and applicable specification of cutting tool for certain type of machining material.
d) To differentiate which cutting tool best for producing clean and clear surface during machining process.
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Universally, there are two major types of cutting tool that have been used widely in the field of manufacturing industries. First are flat end mill and the other one is ball end mill. There are also a thousands cutter are made by the tool manufacturers nowadays with so much applications and the ability in different kind of cutting conditions, but most of it are inspired by these, flat and ball cutter. Both of this type of cutter plays a huge role on the metalworking industry as it contribute a lot more on the manufacturing process especially in the making of mold and die component.
Each cutter are applied on different ways of cutting mechanism and when it comes to cutting process, each cutter can provides its own ability based on the shape of the part that needed to be cut. In this research paper, both type of cutter are chosen in this experiment as both of it are used widely in the electric and electronic company mainly in the manufacturing of die and mold in their production department. These cutters come with two different properties of material, carbide and High Speed Steel (HSS) as these materials can be applied on different process with different type of machining material.
In further view of this wear investigation, 32 cutters were used in order to find out the effects of the wear mechanism on the cutters from different aspect. In this case, there are 2 different type of work material, SS 41 and Copper Tungsten, different machining parameters, cutting tool material, and the cutting time. The machining time for this experiment are made in 4 gaps of time, 35 minutes, 70 minutes, 105 minutes and 140 minutes as already marked before that based on the assumption, the wear phenomena occurred in 120 minutes or 2 hours of machining time.
From this parameters, analysis will be made using Scanning Electron Microscope (SEM) and this including surface roughness of the work material based the effects of wear from the cutting tool. Resulting from the analysis, a conclusion can be made based on which condition the wear can occurred as there are many point of view to show exactly what causing the wear phenomena.
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5
CHAPTER 2
LITERATURE REVIEW
2.1 Cutting Tool
Success in metal cutting depends on selection of the proper tool (material and geometry) for a given work material. A wide range of cutting tool material is available with a variety of properties, performance capabilities and cost. These include high carbon steels and low / medium alloy steels, high speed steels, cast cobalt alloys, cemented carbides, cast carbides, coated carbides, coated high speed steels, ceramics, cermets, whiskereinforced ceramics, sialons, sintered polycrystalline cubic boron nitride (CBN), sintered polycrystalline diamond and single crystal natural diamond.
The tool materials are ranked by the maximum cutting speed needed to machine a volume of steel materials, assuming equal tool lives. As the speed increases, so does the material removal rate. The time required to remove a given unit volume of material therefore decreases. The cutting tool material, cutting tool parameters and tool geometry selected directly influence the productivity of the machining operation. The elements that influence the decision are work material characteristics (chemical and metallurgical state), part characteristics (geometry, accuracy, finish and surface integrity requirements), machine tool characteristics, including the work holders (adequate rigidity with high horsepower, and wide speed and feed ranges) and support systems (operators ability, sensors, controls, method of lubrication and chip removal).
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LIST OF ABBREVIATIONS, SYMBOLS, SPECIALIZED
NOMENCLATURE
NCS - Numerical Control Sculpture machine FCM - Fujitsu Component (M) Sdn. Bhd. SEM - Scanning Electron Microscope SS 41 - Material Code for Mild Steel HSS - High Speed Steel
NC - Numerical Control CBN - Cubic Boron Nitride
EDM - Electric Discharge Machine
CNC - Computer Numerical Control machine CAD - Computer Aided Design
CAM - Computer Aided Manufacturing DTI - Dial Tester Indicator
µm - Micrometer
Ra - Roughness Average @ Arithmetic Average rpm - Revolution per minute
mm - Millimeter
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CHAPTER 1
INTRODUCTION
1.1 Background
Nowadays there are so many types of cutting tool in the market all around the world. In the past few years, only certain cutting tool that exists in the catalogue of tool manufacturers with the similar name of cutting tool like flat cutter or ball cutter. But these days, more than 10 or even hundreds cutter with the name flat cutter in front of it, have so much with its various shape, consists differ material and for sure with so much variety in its application. This situation comes consistent with the daily improvement from all the tool manufacturers in the metalworking industry as the machines technology always comes forward very fast and all the machining process has to be done in time with absolutely high quality in its product.
In this case, a whole lot more can be seen especially when it is related with manufacturing of cutting tool in globally. Each and every cutting tool that has been developed must has its specific applications. As it always correlated with the shape of material that has to be cut, type of the material, cutting conditions, cutting parameters and cutting process itself, as usual are divide into two processes, roughing and finishing. When a tool change is needed or anticipated, a performance comparison should be made before selecting the right tool for the job and in this case the phrase “the most expensive tool is always the best tool” should be considerate more. The best tool is the one that has been carefully chosen to get the job done quickly, efficiently and economically.
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1.2 Problem Statements
Wear phenomena has always been a nightmare in the industrial environment, especially when it involved with machining process as it absolutely affecting the quality of a part. In the present days, with so many modern and high technologies machines are developed everyday, mostly every part product are machined by a high technology machine and running the whole cutting process without being observed by a human being. In that matter, if once the wear occurred on the cutting tool, the technicians won’t realize it until the whole process is completely done. The consequences from this incident, is it will cause a mess of the quality surface material and the most bad news is, it won’t obtain the exact and accurate dimensions, yet far from the part tolerances.
As getting inspirational from this kind of situations, this paper are consists research of this wear mechanism and in the mean time includes the investigation of wear characteristics on cutting tool that emerge on a high technology and NC type machine. This machining experimentation is carried out using a CNC Milling machine or its original name is Numerical Control Sculpture (NCS) machine. Moreover, this machine runs based on NC program, have the ability to cuts various shapes on a material and can runs in a longer period of time. The NC programmer is developed based on design of the material shape that are adapt from EDM electrode of Keytop using a CAD/CAM program called I-Deas.
This collaboration project is held with the company that produces computer and electronic components; keyboard for desktop computer and laptop, mouse and relay. Fujitsu Component (M) Sdn. Bhd. is a very well known company especially in the quality of its product and great reception from all customers all over the world. The products from this company are among the highest choice from customers as Fujitsu have already built their names long enough. Besides that, the company has been certified with ISO 9001, QS 9000 and ISO 14001. All the staffs here are committed to their work, very innovative and professional worker and have a very good teamwork between staff.
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1.3 Objectives of the Research
The main objective of this research is to investigate optimum parameter for NCS:
a) Tool life (machining time capabilities before maximum wear)
According to Mr. Rosni b. Sulaiman (technician incharge of machines in 3rd process room) approximately maximum tool wear occurred at 2 hours machining duration in usual machining process. But in details there is still no clear description whether on that time, maximum tool wear really occurred or not. For that matter, this research paper is developed to investigate the characteristic of tool wear according to cutting time transition. The experiment will be conducted using Scanning Electron Microscope (SEM) in Metrology Lab in UTeM.
b) Surface quality according to the cutting time and tool wear.
On the same time, the visual of surface machined also can be investigate according to the cutting time based on the effects of the cutting process between the cutting tool and the machining material. From here, the differences can be seen between the wear cutting tool and the good one.
Other objectives of the experiment to be achieved are:
a) To determine the main reason that causing the wear to occurred on the cutting tool during machining process.
b) To explore the characteristics and properties of material used in each cutting tool, including the work material.
c) To know the exact and applicable specification of cutting tool for certain type of machining material.
d) To differentiate which cutting tool best for producing clean and clear surface during machining process.
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Universally, there are two major types of cutting tool that have been used widely in the field of manufacturing industries. First are flat end mill and the other one is ball end mill. There are also a thousands cutter are made by the tool manufacturers nowadays with so much applications and the ability in different kind of cutting conditions, but most of it are inspired by these, flat and ball cutter. Both of this type of cutter plays a huge role on the metalworking industry as it contribute a lot more on the manufacturing process especially in the making of mold and die component.
Each cutter are applied on different ways of cutting mechanism and when it comes to cutting process, each cutter can provides its own ability based on the shape of the part that needed to be cut. In this research paper, both type of cutter are chosen in this experiment as both of it are used widely in the electric and electronic company mainly in the manufacturing of die and mold in their production department. These cutters come with two different properties of material, carbide and High Speed Steel (HSS) as these materials can be applied on different process with different type of machining material.
In further view of this wear investigation, 32 cutters were used in order to find out the effects of the wear mechanism on the cutters from different aspect. In this case, there are 2 different type of work material, SS 41 and Copper Tungsten, different machining parameters, cutting tool material, and the cutting time. The machining time for this experiment are made in 4 gaps of time, 35 minutes, 70 minutes, 105 minutes and 140 minutes as already marked before that based on the assumption, the wear phenomena occurred in 120 minutes or 2 hours of machining time.
From this parameters, analysis will be made using Scanning Electron Microscope (SEM) and this including surface roughness of the work material based the effects of wear from the cutting tool. Resulting from the analysis, a conclusion can be made based on which condition the wear can occurred as there are many point of view to show exactly what causing the wear phenomena.
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CHAPTER 2
LITERATURE REVIEW
2.1 Cutting Tool
Success in metal cutting depends on selection of the proper tool (material and geometry) for a given work material. A wide range of cutting tool material is available with a variety of properties, performance capabilities and cost. These include high carbon steels and low / medium alloy steels, high speed steels, cast cobalt alloys, cemented carbides, cast carbides, coated carbides, coated high speed steels, ceramics, cermets, whiskereinforced ceramics, sialons, sintered polycrystalline cubic boron nitride (CBN), sintered polycrystalline diamond and single crystal natural diamond.
The tool materials are ranked by the maximum cutting speed needed to machine a volume of steel materials, assuming equal tool lives. As the speed increases, so does the material removal rate. The time required to remove a given unit volume of material therefore decreases. The cutting tool material, cutting tool parameters and tool geometry selected directly influence the productivity of the machining operation. The elements that influence the decision are work material characteristics (chemical and metallurgical state), part characteristics (geometry, accuracy, finish and surface integrity requirements), machine tool characteristics, including the work holders (adequate rigidity with high horsepower, and wide speed and feed ranges) and support systems (operators ability, sensors, controls, method of lubrication and chip removal).