UNIVERSITI TEKNIKAL MALAYSIA MELAKA

EFFECT OF INCLINED BALL MILLING PROCESS ON

ALUMINIUM ALLOY

This report submitted in accordance with requirement of the Universiti Teknikal

Malaysia Melaka (UTeM) for the Bachelor Degree of Manufacturing

Engineering (Manufacturing Process) with Honours.

By

NUR HANANI BT MAT ZALI

FACULTY OF MANUFACTURING ENGINEERING

April 2010

UNIVERSITI TEKNIKAL MALAYSIA MELAKA (UTeM)

BORANG PENGESAHAN STATUS TESIS*

JUDUL: EFFECT OF INCLINED BALL MILLING PROCESS ON ALUMINIUM ALLOY

SESI PENGAJIAN: 2009/2010

Saya NUR HANAN I BT MAT ZALI

mengaku membenarkan tesis (PSM/Sarjana/Doktor Falsafah) ini disimpan di Perpustakaan Universiti Teknikal Malaysia Melaka (UTeM) dengan syarat-syarat kegunaan seperti berikut:

1. Tesis adalah hak milik Universiti Teknikal Malaysia Melaka. 2. Perpustakaan Universiti Teknikal Malaysia Melaka dibenarkan membuat salinan

untuk tujuan pengajian sahaja. 3. Perpustakaan dibenarkan membuat salinan tesis ini sebagai bahan pertukaran

antara institusi pengajian tinggi. 4. **Sila tandakan ( ,r)

D SULIT

D TERHAD

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

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

(TANDATANGAN PENULIS)

~ Disah ffn oleh:

t? ... ~

Alamat Tetap: 335 JALAN MUSTAFFA, KG PENAMBANG 15350, KOTA BHARU, KELANTAN Tarikh:9 APRIL 2010

~~~

(TANDJ TA~ GAN PENYELIA) MOHAMAD RIOZUAN BH·• J;

• Pensyarah Cop Rasm1: Fakulti Kejuruteraan f'embuatan

Universiti Teknikal Malayaia Melaka

Tarikh: 2 ~ / 'r" ltD i I

* Tesis dimaksudkan sebagai tesis bagi ljazah Doktor Falsafah dan Sarjana secara penyelidikan, atau disertasi bagi pengajian secara kerja kursus dan penyelidikan, atau Laporan Projek Sarjana Muda (PSM).

** Jika tesis ini SULIT atau TERHAD, sila lampirkan surat daripada pihak berkuasa/organisasi berkenaan dengan menyatakan sekali sebab dan tempoh tesis ini perlu dikelaskan sebagai SULIT atau TERHAD.

DECLARATION

I hereby, declared this report entitled "Effect of Inclined Ball Milling Process on

Aluminium Alloys " is the results of my own research

Signature

Author's Name

Date

except as cited in references.

11

· · · ··~···· · ·· · · NUR HANANI MAT ZALI

19th APRIL, 201 0

APPROVAL

This PSM submitted to the senate ofUTeM and has been as partial fulfillment of the

requirements for the degree of Bachelor of Manufacturing Engineering

(Manufacturing Process). The member of the supervisory committee is as follow:

MOHA n rah

Fakulti Kejurute an Pembuatan .••••.• !J.'liyPr,iP. T!~tkAI.t~f!•.Y.~i!l. ~l~ ....

Mr. Mohamad Ridzuan bin Jamli

Main Supervisor

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ABSTRACT

Milling is one of the fundamental forms of machining operation among several

industrial machining processes. The inclination of the cutting tool is one of the

important factors that influence the surface finish which become a requirements in a

variety of manufacturing industries including the aerospace, die-mold and

automotive industries where complex surfaces and geometries are machined. The

three sectors are stressed most on the quality of the surface finish. Thus, the main

objective for this study is to investigate the effect of the inclined ball end milling to

the scallop height of the Aluminium Alloys surface. Machining parameters involved

in this study are lead angle, tilt angle and step over. The material used to test its

scallop is Aluminium Alloys. Full factorial design of DOE by using the Design

Expert software was applied in order to determine the test run for the experiment. It

also used to analyze the data obtained from the experiments. There were two method

used in this study in order to get the accurate result which are Simulation modeling

using CA TIA software and Experimental machining using the 3-axis CNC milling

machine. The result for both processes showed that the scallop height was decreased

when the tilt angle increased.

lV

ABSTRAK

Proses kisar adalah salah satu bentuk: asas operasi pemesinan antara proses

pemesinan yang terdapat dalam industri. Kecondongan mata alat merupakan salah

satu factor penting yang mempengaruhi permukaan akhir produk yang menjadi

keperluan dalam pelbagai industri pembuatan termasuklah sector ruang angkasa,' die­

mold'dan automotif. Ketiga-tiga sektor ini sangat menekankan terhadap kualiti

permukaan yang terhasil. Oleh itu, objektif utama kajian ini adalah untuk: mengkaji

kesan peningkatan sudut mata alat dalam 'ball end milling' terhadap kekasaran

permukaan bahan kerja. Pembolehubah yang terlibat dalam kajian ini adalah sudut

'lead', sudut 'tilt' dan 'step over'. Bahan yang akan digunakan untuk: menguji

kekasaran permukaannya adalah aloi Aluminium. Kaedah "full factorial"

menggunakan 'Design Expert' digunakan untuk: menentukan bilangan ujikaji perlu di

jalankan. Ia juga akan digunakan kemudian bagi menganalisis data yang akan

diperolehi. Dua jenis ujikaji telah dilakukan untuk: mendapat hasil yang lebih tepat

telah digunakan iaitu Model simulasi dari 'CATIA' dan experiment mesin

menggunakan 3 paksi mesin CNC. Pencapaian yang didapati melalui kedua-dua uji

kaji tersebut menunjukkan ketinggian lekukkan di permukaan adalah berkuarang

apabila sudut 'tilt' bertambah.

v

DEDICATION

To my beloved parents Mat Zali bin Junoh and Azizah Ismail, thank you for your

continuous support and thanks for everything. My sisters and brothers, thank you for

encouraging me to do well in this writing.

VI

ACKNOWLEDGEMENTS

All praise to almighty Allah S.W.T. I am thankful for the strength and patience He

has given within me to complete this Bachelor Degree Project as a part of program

Manufacturing Engineering. I am Deepings grateful and thankful to my supervisor,

Mr. Mohamad Ridzuan bin Jamli that had been so helpful in supervised, taught and

relayed the technique and knowledge when undergo my thesis. I am realize that his

guidance and advice has made this a much better thesis. I also wish my appreciation

to Mr. Khairul Efendy Mansor, the technician who had lending his hand in helping

me through the machine handling. I am particularly indebted for your help and

experience through my thesis. A special word of thanks also is due to the people

closer to me such as friends and colleagues who gave me opportunity to develop my

writing and to all the UTeM lecturers and staffs. More, I like to take this opportunity

to say at this juncture, it is only logical for me to pay tribute to my family. Their

undivided love and support are the beacons that have continued to motivate me

through the harshest of situations and I believe it will also spur me on to greater

achievement in the future. And with the blessing of Allah I could finish this thesis.

Thanks to all of you. Finally, I would like to wish thank you a lot to anybody who

has given all the support and contribution to me in this thesis directly or indirectly.

Thanks to all of you.

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TABLE OF CONTENT

Declaration 11

A pro val 111

Abstract IV

Abstrak v

Dedication vi

Acknowledgements Vll

Table of contents Vlll

List of figures XI

List of tables xiii

List of abbreviation XIV

1. CHAPTER 1: INTRODUCTION 1

1.1 Background of the Study I

1.1.1 Ball End Milling 2

1.1.2 The Effect of the Inclined Ball Milling Process 2

1.2 Problem Statement 4

1.3 Objective 5

1.4 Scope of Project 5

1.5 Structure of Project 6

1.6 Gantt Chart 8

2. CHAPTER 2: LITERATURE REVIEW 10

2.1 Introduction 10

2.2 Tool Orientations 10

2.3 Lead and Tilt angle 12

2.3.1 Lead angle 12

2.3.2 Tilt angle 13

2.4 Effect of Lead and Tilt Together with Step Over 14

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2.5 Effect on Cutting Speed and Depth of cut 16

2.6 DepthofCut 18

2.7 Cutter Path Orientation. 20

2.7.1 Four Types of Cutter Path Orientation. 20

2.8 Feed (mm/tooth) 22 2.9 Work piece material 23 2.9.1 Aluminium alloys 23 2.10 Cutting Tool material 24 2.10.1 High-speed Steel 24 2.10.2 Cast-Cobalt Alloys 25 2.10.3 Carbide 25 2.11 Cutting Fluids 24 2.11.1 Lubricant 27 2.12 Surface quality 27 2.12.1 Surface Finish Parameters 28

3. CHAPTER 3: METHODOLOGY 30

3.1 Introduction 30 3.2 Identification of Process Parameters 32 3.2.1 Simulation Machining Parameter 33 3.2.2 Experimental Parameter 33 3.2.3 Design Expert Software analysis 34 3.3 Simulation Process (CATIA) 36 3.4 Machining Process 38 3.4.1 Machining Tool 39 3.5 Measurement 40

ix

4. CHAPTER 4: RESULT AND DISCUSSION

4.1 Result

4.1.1 Results for the Simulation Modeling Process

4.1.2 Analysis ofVariance (ANOVA)

4.1.3 Diagnostic

4.1.4 Model Graph

4.2 Experimental and Machining Process

4.2.1 Analysis OfVariance (ANOVA)

4.2.2 Diagnostic

4.2.3 Model Graph

4.3 Comparison between Simulation Process and Experimental machining

process

4.4 Machining error

4.4.1 Vibration

4.4.2 Tool wear

4.4.3 Parallax error

S. CHAPTERS: CONCLUSION AND RECOMMENDATION

5.1 Conclusion

5.2 Recommendation

REFERRENCES

APENDICES

A Drafting sheet for Experimental Machining work piece

B Drafting sheet for Simulation Modeling work piece

C Result sheet for Simulation Modeling

D Analysis of optimization for Simulation Modeling Process

E Analysis of optimization for Experimental Machining

F Stereo Zoom Microscope Specification

X

42

42

42

43

44

47

51

52

53

55

60

61

61

61

62

63

63

64

65

LIST OF FIGURES

1.1 Definition of tool orientation and inclination.(Terai et. al.) 3

1.2 An illustration and tool chip contact areas of four different paths

Orientations. (C.K. Toh) 4

1.3 The Process Flow Chart of the PSM I and PSM II 7

2.1 Coordinates system of5-axis milling operations (Ozturk et al.,2009) 11

2.2 Lead and Tilt angle. (Ozturk et al.,2009) 12

2.3 Indentation case (Ozturk et al.,2009) 13

2.4 Scallop height,h5, a) s ~ 2Ro cost b) s 2:: 2Ro cost (Ozturk et al.,2009) 15

2.5 Tool inclination 45° 17

2.6 Tool inclination 38° 17

2.7 An illustration of four different cutter path orientation.( Toh.2004) 20

2.8 Tool chip contact areas on cutter plane based on different cutter

pathorientation. ( Toh,2004) 20

2.9 Cutting Forces Measured With Different Cutter Orientation. 21

2.10 The path-interval scallop and feed interval scallop of ball end milling.

(J.S. Chen,2005) 22

2.11 HSS end milling cutter 24

2.12 Carbide ball end milling cutters 25

3.1 Flowchart of Methodology for the process 31

3.2 Simulation modelling process 36

3.3 Measurement of the scallop height using CATIA software 37

3.4 Projection View of the work piece 38

3.5 Surface Machined 39

3.6 Haas CNC 3-axis milling machine 39

3.7 Carbide Cutting Tool 40

3.8 Stereo Zoom Microscope EMZ-13 TR 41

3.9 Scallop height measurement 41

4.1 Normal plot of residuals 44

4.2 Graph of Residual vs predicted 45

4.3 Graph of residuals vs. run 45

XI

4.4 Box-Cox Plot for Power transforms 46

4.5 Interaction between Tilt angle and Lead angle 47

4.6 Interaction between Step over and Lead angle 48

4.7 Interaction between Tilt angle and step over 49

4.8 Interaction between lead angle and step over 50

4.9 Normal plot of residuals 53

4.10 Residual vs. Predicted 54

4.11 Residuals vs. Run 54

4.12 Box-Cox for Power transforms 55

4.13 Interaction of Lead Angle and Tilt angle 56

4.14 Interaction of Step Over and Lead angle 57 4.15 Interaction of Lead angle and Step Over 58 4.16 Interaction of Tilt Angle and Step Over 59

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LIST OF TABLES

1.6 Ghantchart 8

2.1 Milling Machine Cutting Speed 16

2.2 Comparison between Cutting Speed and Depth of cut due to the Angle 18

2.3 Typical properties of Aluminium Alloys 23

3.1 Parameter for simulation machining process 33

3.2 Experimental Parameter 33

3.3 Design Summary for Simulation Modelling Process 35

3.4 Design Summary for Experimental machining 35

4.1 Results for ANOV A 43

4.2 Result for the Machining Experiment 51

4.3 ANOV A for the experimental machining 52

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AA

ANOVA

CATIA

NC

CLA

CNC

LIST OF ABBREVIATION

Arithmetic Average

Analysis OfVariance

Computer Aided Three-dimensional Interactive

Application

Numerical Control

Centre Line Average

Computer Numerical Control

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1

CHAPTER 1

INTRODUCTION

1.1 Background of the Study

Manufacturing of parts with complex surfaces brings additional challenges such as

tool accessibility and contouring. Five- axis milling provides much better

accessibility with the help of increased tool orientation capability. However, 5-axis

milling also brings extra difficulties due to the complicated process geometry and

mechanics. Lead and tilt angles determine orientation of cutting tool and the

engagement region, and affect the mechanics and dynamics of the process. Local

chip thickness, cutting force coefficients, dynamic forces and stability are affected

by lead and tilt angles. Improper tool orientation may result in decreased

productivity and part quality due to higher cutting forces, surface form errors and

process instability. Thus, lead and tilt angles are very important parameters in 5-axis

milling processes. Effects of lead and tilt angles on the process are not known very

well, and cannot be easily estimated unlike parameters such as feed rate and cutting

depths. Lead and tilt angles have effects on different factors such as tool tip contact

with the work piece, scallop height, cutting forces, torque, form errors and stability.

(Ozturk et al.,2009)

2

1.1.1 Ball End Milling

A ball end mill is well suited to milling many types of materials, from plastics to

steel alloys and titanium. The toughness and durability of the cutting edge is very

high in ball end mills because of the rounded edge design. This fact is actually just a

by product of the rounded cutting edge. Originally it was rounded for a specialized

purpose, namely for milling grooves with a semi-circular cross-section. This type of

groove is an important part of the metal bearings used in many machines.

Another benefit of the way the ball end mill is designed is that it can handle very

high feed rates, meaning it can mill the material very quickly. This gives it great

productivity for use in today’s milling machines. The smooth geometry of the cutting

tip also translates into lower cutting forces, giving the cutter added strength under

pressure. Since it is less likely to break under normal forces, the ball end mill is also

highly cost-effective for the applications to which it is suited.

Ball end mills are almost always made of tungsten carbide, a high-strength metallic

compound containing tungsten and carbon. Tungsten carbide powder is pressed into

rods, which are then ground and sharpened to various specifications. A typical ball

end mill will often be manufactured with a protective coating. These coatings usually

contain titanium mixed with other elements such as carbon and aluminium.

1.1.2 The Effect of the Inclined Ball Milling Process

As already it has been researched, various cutting process conditions are very

important in the developed surface roughness of machined surface. One such cutting

condition with important effect in the quality of surface is the inclination angle

between the cutting tool and the work piece, during the cutting process. The

placement of cutting tool can be differentiated, depending on the inclination angle

3

between the tool and the processed surface and the feed direction. These result in

different milling strategies that consequently lead to different surface quality. The

reasons for this behaviour are the different cutting speed of the cutting edge, the

different shapes of chips per case and the variability of the developed cutting forces.

Figure 1.1: Definition of tool orientation and inclination.(Terai et. al.)

Fig.1 illustrates the definition of the tool orientation. Z axis is the normal direction of

the surface of the work piece in machining. Y axis is the direction of feeding the

tool. So, x-axis is the direction of pick feed. On this coordination 2 defined for the

tool orientation. One is the angle between z axis and a plane including the tool

rotation axis and y axis. It is called “the angle of pick feed direction ωp”. In this case

we define another coordination xtytzt. This coordination is inclined ωp around y axis.

So yt zt plane include the tool rotation axis. In this plane the angle between the tool

rotation axis and z t axis is called “the feed direction angle ωf”. (Terai et. al.)

4

Figure 1.2: An illustration and tool chip contact areas of four different path orientations. (C.K. Toh)

1.2 Problem Statement

The finish milling on the plane surface using ball end milling generally

results in poor tool life since the effective cutting speed at its tip is zero and the

effective cutting speed is very small. The different contact area of the cutting tool

will lead to the different cutting speed of the machining process. Step over also will

influence the scallop height produce on the surface. The different of inclination angle

and cutter path orientation will result the different surface finish. This experimental

study is purposely to investigate the inclination angle as well as the cutter path

orientation in order to get the best surface.

5

1.3 Objective

The purposes of this study are:

i. Investigation using the CATIA simulation

ii. To investigate the effect of the inclined ball end milling to the scallop height

of the Aluminium Alloys surface.

iii. To compare the results between the experimental machining with the CATIA

simulation machining

1.4 Scope of Project

This study is mainly about the experimental test of the Ball end milling process to

study the effects of the inclination of Ball End Milling process on the Aluminium

Alloys. The study will include the effect of the inclination to the surface roughness

of the Aluminium Alloys using four different cutter path orientation of the cutting

tool. Different inclination angle of the Ball end milling machine will result different

surface roughness. Hence, this study is to discover the suitable inclination angle to

produce the best surface roughness of Aluminium Alloys. The study takes into

account the orientation of the cutting tool, with respect to the work piece, offering

the possibility to alter the tool inclination angles. The study is focus primarily on the

Ball End Milling Process on Aluminium Alloys to identify the effect of the

inclination angle of the process on the Aluminium Alloys. The study is considered in

three aspects which are inclination angle of the cutting tool (30°), speed of the

cutting tool, and also the cutter path orientation consist of horizontal upward,

horizontal downward, vertical upward, vertical downward. The method use in the

study are calculation, modelling of the process using CATIA, basic machining of 5-

axis Milling Machine, and measurement for the surface roughness which using

surface profilometers. Above all, this study uses the Design of Experiment (D.O.E)

method in analyzing the result.

6

1.5 Structure of Project

Generally, this report is divided into two parts which are Projek Sarjana Muda

(PSM) I and PSM II. In total, this report contains of five main chapters. These

chapters are separated into two parts which the first part contains three chapters

which are introduction, literature review and methodology whereas the second part

conducts the two more chapters, results and discussion and finally, conclusion and

recommendation of this study.

In the first chapter, Introduction, briefly explain the background of the study about

the Effects of Inclined Ball end Millings process and introduction on the ball end

milling generally. It also contains of the problem statement, objectives, scope and

structure of this project. All theories were taken and referred to the articles, journals,

and some books related to the study are explain in detail in Chapter 2, Literature

Review.

In chapter 3, Methodology, all methods that have been use are explained specifically

in term to achieve the objectives and obtain the result of the study. On the other

hand, in Chapter 4, for the results and discussion, this report are focus primarily on

the data that been collected and identify the influence factor that achieve the result.

Besides, suggestion for improvement on the Ball end Milling process also been

given in this chapter.

In the last chapter, Chapter 5, Conclusion and Recommendation which conclude this

study and also included some suggestion in order to improve this study for future.

Finally, all the chapters are compiled separately in sequences in order to give a clear

view to the readers. The flow chart below shows the general flow of the Projek

Sarjana Muda (PSM) that will be held in two semesters.

7

Figure 1.3: The Process Flow Chart of the PSM I and PSM II

YES

NO

NO

YES

Objectives achieved?

Conclude the project.

Collect the data of the experiment and see the results.

PSM presentation

End

Projek sarjana muda (PSM) II

Do the experimental test using 3-axis CNC machine on the workpiece.

Projek sarjana muda (PSM) I

Choose the project title and do research

Do the modelling using CATIA and see the result.

Conform the project title with the supervisor.

Start research on the Inclined Ball End Milling and gather all the data.

Start working on the calculation of the angle.

Start

Suitable?

Do the simulation modelling using CATIA software.

NO

8

1.6 Gantt Chart

Table 1.1: Gantt chart for PSM1

No Yeat 2009

Activity July Aug Sept Oct Nov

1 PSM title confirmation

2 Problem statement identification

3 objective and scope of study

4 Finding literature review

5 PSM 1 report writing

6 PSM 1 report review

7 PSM 1 report submission

8 Preparation for PSM 1 presentation

9 PSM 1 presentation

Planning

Actual

9

Table 1.2: Gantt Chart for PSM II

No Year 2009

Activity Jan Feb Mar Apr May

1 Improvement on PSM 1 2 Finding literature review 3 Simulatio Modelling using CATIA 4 Machining and material preparation 5 Machining process 6 Surface roughness measurement 7 Data Analysis using Design Expert 8 PSM 2 report writing 9 PSM 2 review

10 PSM 2 submission

11 Preparation for PSM 2 presentation

12 PSM 1 presentation