UNIVERSITI TEKNIKAL MALAYSIA MELAKA
Drilling of Aero Composite Material
Thesis submitted in accordance with the partial requirement of the Universiti Teknikal Malaysia Melaka for the
Bachelor of Manufacturing Engineering (Manufacturing Process)
By:
Farah Umaima Bt. Miswan
B 050410006
Supervisor:
Mr. Raja Izamshah Bin Raja Abdullah
DRILLING OF AERO COMPOSITE MATERIAL
FARAH UMAIMA BT. MISWAN
UTeM Library (Pind.1/2007)
UNIVERSITI TEKNIKAL MALAYSIA MELAKA
BORANG PENGESAHAN STATUS TESIS*
JUDUL: DRILLING OF AERO COMPOSITE MATERIAL
_______________________________________________________________ _______________________________________________________________
SESI PENGAJIAN : 2004/2008
Saya ________ FARAH UMAIMA BINTI MISWAN_____________________________
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. atau kepentingan Malaysia yang termaktub di dalam AKTA RAHSIA RASMI 1972)
(Mengandungi maklumat TERHAD yang telah ditentukan oleh organisasi/badan di mana penyelidikan dijalankan)
(TANDATANGAN PENULIS)
DECLARATION
I hereby, declared this thesis entitled “PSM Title” is the results of my own research
except as cited in references.
Signature : ……….
Author’s Name : FARAH UMAIMA BT. MISWAN
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APPROVAL
This PSM submitted to the senate of UTeM and has been as partial fulfillment of the requirements for the degree of Bachelor of Manufacturing Engineering (Process).
The members of the supervisory committee are as follow:
………
ABSTRACT
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ABSTRAK
Projek ini memfokuskan kepada analisa ke atas kadar feed dan kelajuan mesen CNC untuk proses dril ke atas bahan aero-komposit. Ia juga untuk mengkaji faktor penggunaan jenis-jenis mata dril tertentu seperti Twist, Dagger dan Fish Tail. Projek ini adalah bertujuan untuk mengkaji nilai faktor, jenis mata alat yang paling sesuai dan penggunaan
backup plate untuk meminimakan atau menghapuskan kerosakan ke atas bahan kerja
DEDICATION
To my beloved family and friends
Miswan Sairi
Fatimah Embong
Fatin Najwa
Nurul Nadia
Amirul Asyraf
Ammar Faiz
Aiman Syafiq
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ACKNOWLEDGEMENTS
First and foremost, I would like to dedicate my deepest gratitude to Universiti Teknikal Malaysia Melaka (UTeM), for the opportunity to do this study and use any equipment and material available in the laboratory.
A special thanks to my supervisor, Encik Raja Izamshah bin Raja Abdullah for the supervision along the time I was doing this project. I greatly appreciate his consistent encouragement, advice and invaluable guidance throughout the course of this project.
I wish to extent my special appreciation to manufacturing engineer in CTRM Sdn Bhd, Encik Adlee bin Hisyamuddin, and also to Encik Zulfadli bin Rahmat for their generosity, supports, comments and valuable time to help me complete this project.
TABLE OF CONTENTS
List of Abbreviations, Symbols, Specialized Nomenclature………xv 1. INTRODUCTION……….....1
2.5 CNC Machining Process………12
2.5.1 Machine Technical Data…………..………12
2.5.2 Chiller Unit………..13 2.5.3 Dust Extraction……….………15
2.5.4 Tool Changes………16
2.5.5 File Transfer………17
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2.5.7 Work Offset Setting………..18
2.5.8 Program Execute………..19
2.5.9 Spindle Jogging………19
2.5.10 Safety………...20
2.6 Computer Numerical Control(CNC) Drilling………20
2.7 Machining Characteristic………22
2.7.1 Surface Roughness………22
2.7.2 Measuring Surface Roughness………22
2.7.3 Maximum Force of Flexural Test………23
2.8 Influence of Process Parameters on Cutting Force and Torque………..25
2.9 Design of Experiment……….……….25
2.9.1 Full factorial Design………27
2.10 Previous Researches……….28
3.2.3 Step 3: Identify Suitable Response Variables………...36
3.2.4 Step 4: Select the Appropriate Orthogonal Array (OA)………...36
3.2.5 Step 5: Preparation of Experiment………....37
3.2.5.1 Drill Bits Preparations………...37
3.2.5.2 Workpiece and Backup Plate Preparation……….40
3.2.5.3 Experiments Procedure and Equipments………...41
3.2.5.4 Testing and Observation………42
3.2.5.4.1 Surface Roughness……….42
3.2.5.4.2 Maximum Force of Flexural Test……….……..43
3.2.5.4.3 Observation on Hole Quality by using Scanning Electron Microscope (SEM)……….44
3.2.6 Step 6: Analyzed and Interpreted Results of Experiment Trials………….45
3.2.7 Step 7: Conclusion and Recommendation……….……..45
4. RESULTS AND DATA ANALYSIS……….…….47
4.1 Introduction………...47
4.2 Findings and Data Analysis of Surface Roughness………...48
4.2.1 Normal Probability Plot of Effects for Surface Roughness ………51
4.2.2 Pareto Chart of the Effects for Surface Roughness……….54
4.2.3 Main Effects Plot for Surface Roughness………....57
4.2.4 Interaction Plot for Surface Roughness ………..…60
4.3 Findings and Data Analysis of Maximum Force ……….…..….63
4.3.1 Normal Probability Plot of Effects for Maximum Force of Flexural Test……….64
4.3.2 Pareto Chart of the Effects for Maximum Force of Flexural Test………..67
4.3.3 Main Effects Plot for Maximum Force………...…70
4.3.4 Interaction Plot for Maximum Force ………..…73
4.4 Observation using Scanning Electron Microscope (SEM)………..…76
5. DISCUSSION………..79
5.1. Discussion on Surface Roughness………..79
5.2 Discussion on Maximum Force of Flexural Test……….…81
5.3 Discussion on Image Analysis by Scanning Electron Microscope……….83
5.3.1 Discussion on Delamination……….86
5.4 Discussion Summary………...88
6. CONCLUSION AND RECOMMENDATION………...90
6.1 Conclusion of Study………90
6.2 Recommendation for Future Works………92
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REFERENCES………..………..93
APPENDICES
A Sketching of material drilling and DOE B Picture of Machining Method and Testing C Graph of Flexural Test
LIST OF FIGURES
2.1 Trailing Edge panel No.9 Bonded Right Hand of Airbus 320 plane. 10
2.2 The tracking panel number. 11
2.3 Computer Numerical Control (CNC) Drilling 21
2.4 Path of stylus in surface roughness measurement. 23
2.5 Portable surface roughness measuring machine. 23
2.6 UTM machine for flexural test. 24
3.3 Workpiece of aero composite material 40
3.4 Wood backup plate 41
3.5 Axis Ultra 5 Machining Centre 41
3.6 Portable Surface Roughness Tester (Mitutoyo Surftest SJ-301) 42
3.7 UTM machine for flexural test. 43
3.8 Flexural test. 43
3.9 Scanning Electron Microscope 44
3.10 Specimen orientation 44
3.11 Project Flow Chart 46
4.1 Normal probability plot of effects for surface roughness (Twist Drill)
51
4.2 Normal probability plot of effects for surface roughness (Dagger Drill)
52
4.3 Normal probability plot of effects for surface roughness (Fish Tail Drill)
53
xiii
4.6 Pareto chart of the effects for surface roughness (Fish Tail Drill) 56 4.7 Main effect plot for surface roughness (Twist Drill) 57 4.8 Main effect plot for surface roughness (Dagger Drill) 58 4.9 Main effect plot for surface roughness (Fish Tail Drill) 59 4.10 Interaction plot for surface roughness (Twist Drill) 60 4.11 Interaction plot for surface roughness (Dagger Drill) 61 4.12 Interaction plot for surface roughness (Fish Tail Drill) 62 4.13 Normal probability plot of the effects for maximum force
(Twist Drill)
64
4.14 Normal probability plot of the effects for maximum force (Dagger Drill)
65
4.15 Normal probability plot of the effects for maximum force (Fish Tail Drill)
66
4.16 Pareto chart of the effects maximum force (Twist Drill) 67 4.17 Pareto chart of the effects maximum force (Dagger Drill) 68 4.18 Pareto chart of the effects maximum force (Fish Tail Drill) 69 4.19 Main effects plot for maximum force (Twist Drill) 70 4.20 Main effects plot for maximum force (Dagger Drill) 71 4.21 Main effects plot for maximum force (Fish Tail Drill) 72 4.22 Interaction plot for maximum force (Twist Drill) 73 4.23 Interaction plot for maximum force (Dagger Drill) 74 4.24 Interaction plot for maximum force (Fish Tail Drill) 75
5.1 Experiment T3 without using backup plate. 83
5.2 Experiment T7 with using backup plate 83
5.3 Experiment D4 without using backup plate. 84
5.4 Experiment D8 with using backup plate. 84
5.5 Experiment F3 without using backup plate. 85
5.6 Experiment F7 with using backup plate 85
5.7 Mechanism of delamination: (a) peel-up at entrance and (b) push-out
87
5.8 Schematic of drilling aero composite material. 87
LIST OF TABLES
2.1 Machine Technical Data of Axis ultra 5 Machining Centre 12 2.2 Fundamental pattern of a 2-level, 3 factor full factorial design 27
2.3 Summary of findings from past researches 28
3.1 Factors and levels selected for the experiment 36
3.2 Experimental layout with response value 37
4.1 Surface roughness for experiment using Twist drill. 48 4.2 Surface roughness for experiment using Dagger drill. 49 4.3 Surface roughness for experiment using Fish Tail drill. 50 4.4 Experiment results for maximum force of flexural test 63 4.5 Image analysis of composite drilled using Twist drill 76 4.6 Image analysis of composite drilled using Dagger drill 77 4.7 Image analysis of composite drilled using Fish Tail drill 78
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LIST OF ABBREVIATIONS, SYMBOLS, SPECIALIZED
NOMENCLATURE
CNC - Computer Numerical Control
CTRM - Composites Technology Research Malaysia
DoE - Design of Experiment
FEP - Fluorinated ethylene-propylene GFRD - Glass fiber reinforce prepreg
OA - Orthogonal Array
PFA - Perfluoroalkoxy polymer resin PTFE - Polytetrafluoroethylene
Ra - Roughness average
SEM - Scanning Electron Microscope
CHAPTER 1
INTRODUCTION
1.1 Background
Composites are two or more material that is combined to form a much stronger structure than either material itself. Matrix and reinforce material retains its unique identity in the composite which not melted together as in a metal alloy. Each material contributes its own structural properties. Advance composites are generally considered to be composite which exhibit higher strength to weight ratios than the
composite made of “ordinary” fiberglass and resin. They are more expensive than ordinary composite (U.A. Khashaba, M.A. Seif and M.A. Elhamid, 2006).
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concentration, delamination, and micro cracking associated with machined holes significantly reduce the composite performance.
To reduce the defect of aero composite material during drilling process, it is essential to determine the factors, elements, methods and the drill bit features for the drilling operation. It involves many aspects such as the spindle speed rate, feed rate, drill diameter, specific cutting pressure, the thrust force, torque, drill temperature, tool design parameters and the influence of tool wear.
1.2 Problem Statement
Drilling process of aero composites material is the most critical procedure in the whole aspect of its manufacturing process. Any defects that lead to the rejection of the parts represent an expensive loss. In the aircraft industry, drilling associated delamination accounts for 60% of all part rejections during final assembly of an aircraft. The part must be rejects even for the slightest defect because it can risk the life of countless passengers on the aircraft. The composites performances are reduced due to the bad quality of the drilled holes. The hole machining defects have significantly reduced the strength and fatigue life of carbon/epoxy laminates.
influence of tool wear can increases the thrust force. The effect of processing variables also contributes to drilling damage. The effect of chisel edge on the thrust force is linear. The larger the chisel edge, the larger the thrust and the induced delamination (H. Hocheng and C.C. Tsao, 2005). There are still no resolutions to determine delamination-free and burr-free holes in drilling of aero composites material.
1.3 Objectives
(a) To study the performance of three types of drill bit (twist, dagger and fish tail) in drilling of aero composites material.
(b) To investigate the factors and variables that affecting the quality of the hole. (c) To study the application of back up plate for drilling aero composites process. (d) To determine the most suitable value of variables and the best type of drill bit
for drilling aero composites material.
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1.5 Organization
On the first chapter stated about the background of the study and the project that being handle. Then the problems that contribute to the purpose of this project are stated as an overview of the matters that going to be solve. The objectives of this project are also listed down as a guideline to accomplish this personal project. Lastly, the scope and key assumption of this project are stated here to picture the goal of the project.
Chapter two is the literature review of this study and project that consist of introduction to drilling carbon fiber-reinforced composite material, effects of drill bits on drilling of aero composite material, influence of process parameters on cutting force and torque, and backup plate application for drilling process. It reviews about the relevant information to the study.
Chapter three is the methodology that appraises about the methods that been use in this project to accomplish the objectives and the scope of study. It contains the design of experiment, controlled factors, the backup plate application, the machining method, the results analysis and the performance investigations.
Chapter four is the results obtain from the measurement and data analysis that have been done to the drilled aero composite material. All the graphs and tables shows the findings clearly and the finding is elaborated in the sentence form for better understanding.
problems are discussed and related to previous studies. Then it will be summarize for clearer understanding.
Chapter six is the conclusion for this study that concludes all the achieved objectives and also stated the recommendation for improvement for further investigations of the same study in future.
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CHAPTER 2
LITERATURE REVIEW
2.1 Aero Composites
Composites is two or more material that is combined to form a much stronger structure than either material itself. It consists of matrix and reinforcing material which each material retains its unique identify in the composite where they not melted together as in a metal alloy. Each material contributes its own structural properties.
Advance composites are generally considered to be composite which exhibit higher strength-to-weight ratios than do composite made of “ordinary” fiberglass and resin. They are more expensive than ordinary composite and the properties are usually precisely tailored to achieve specific objective.
when it cures and cannot be reformed or melted after curing that makes it difficult to be recycled (E.g. polyester, vinyl ester, epoxy, phenolic). Thermoplastic undergoes a physical change from solid to liquid when heated and solidifies upon cooling. It can be reheated and reformed, melted at high temperatures and recyclable (E.g. Plexiglas, polyethylene).
There are many types of reinforcing fibers such as Fiberglass (glass cloth), Carbon Graphite, Aramid, Boron, and Ceramic. The fiber orientation is warp, fill (weft), selvage edge, and bias. The fabric styles are unidirectional, bi-directional or multidirectional, and mats. Hybrids are the different type of fiber orientations such as intraply hybrids, interplay hybrids, and selective placement.
There are many possible combinations of resin system and fiber reinforcement and depending upon the specific application the optimum selection can be made. There are some of the most commonly used fibers, along with the most commonly available forms. Carbon fibers have high end low weight high strength application such as structural reinforcement and aerospace parts. Glass fibers have low cost enforcement for general application and widely used in corrosion resistance. Aramid fibers have high end impact absorption application such as ballistic protection.
