UNIVERSITI TEKNIKAL MALAYSIA MELAKA
Surface Integrity of Aluminium Lm6 Alloy When Machine with the
High Speed Steel and Uncoated Carbide Cutting Tool
This report submitted in accordance with requirement of the Universiti Teknikal Malaysia Melaka (UTeM) for the Bachelor Degree of
Manufacturing Engineering (Manufacturing Process)
by
NORAINI BINTI SULAIMAN
B051010241
891122045074
Faculty of Manufacturing Engineering 2013
UNIVERSITI TEKNIKAL MALAYSIA MELAKA
BORANG PENGESAHAN STATUS LAPORAN PROJEK SARJANA MUDA
TAJUK: Surface Integrity of Aluminium Lm6 Alloy When Machine with the High Speed Steel and Uncoated Carbide Cutting Tool
SESI PENGAJIAN: 2013 SEMESTER 2
Saya NORAINI BINTI SULAIMAN
mengaku membenarkan Laporan PSM ini disimpan di Perpust akaan Universit i Teknikal Malaysia Melaka (UTeM) dengan syarat -syarat kegunaan sepert i berikut :
1. Laporan PSM adalah hak milik Universit i Teknikal Malaysia Melaka dan penulis. 2. Perpust akaan Universit i Teknikal Malaysia Melaka dibenarkan membuat salinan
unt uk t uj uan pengaj ian sahaj a dengan izin penulis.
3. Perpust akaan dibenarkan membuat salinan laporan PSM 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 Malaysiasebagaimana yang t ermakt ub dalam AKTA RAHSIA RASMI 1972)
(Mengandungi maklumat TERHAD yang t elah dit ent ukan oleh organisasi/ badan di mana penyelidikan dij alankan)
Alamat Tet ap:
DECLARATION
I hereby, declare this thesis entitled “SURFACE INTEGRITY OF ALUMINIUM LM6 ALLOY WHEN MACHINE WITH THE HIGH SPEED STEEL AND UNCOATED CARBIDE CUTTING TOOL” is the results of my own research except
as cited in the reference.
Signature : ……….
Author Name : ………
Date : ………
APPROVAL
This report is submitted to the Faculty of Manufacturing Engineering of UTeM as a partial fulfillment of the requirements for the degree of Bachelor of Manufacturing Engineering (Process) (Hons.). The member of the supervisory is as follow:
………
i
ABSTRAK
ii
ABSTRACT
iii
DEDICATION
First and foremost, , I would like to express my greatest appreciation to Universiti
Teknikal Malaysia Melaka for giving me the opportunity to undergo my final year
“Projek Sarjana Muda” under the supervision of Dr. Mohd Hadzley Bin Abu Bakar.
A special thank you also goes to my supervisor Dr. Mohd Hadzley Bin Abu Bakar for
his dedication and guidance during the period of undergoing my project and also to
master student Cik Siti Sarah Nadia Binti Ahmad for her guidance. Last but not least,
I want to thank my mom and dad for their support as well as to all my friends Cik Nur
Azza Syazwany Binti Azizol and Nur Nabilah Farhana Binti Sulaiman who never give
up encouraging me to complete this report.
iv
ACKNOWLEDGEMENTS
First of all, I would like to thank Universiti Teknikal Malaysia Melaka for giving me the opportunity to undergo my “Projek Sarjana Muda 2” at the year 4 for semester 2 of my studies.
My hearties appreciation especially to:
• Dr. Mohd. Hadzley Bin Abu Bakar, my supervisor for Projek Sarjana Muda 2, for
his guide and support to complete my final year project. • All the technicians involved in my final year project.
It was their kind efforts that given me opportunity and guidance to successfully undergo my “Projek Sarjana Muda 2” in the final year.
Last but not least, I would like to thanks all my friends that given me full support and encouragement in completing my final year project.
Your help and support will always be cherished.
v
List Abbreviations, Symbols and Nomenclatures xi
CHAPTER 1: INTRODUCTION
2.3 Metal Matrix Composites 6
2.3.1 Stir Casting Method of Fabrication of MMCs 7
2.3.1.1 Stir Casting 7
2.3.2 Strengthening Mechanism of Composites 8 2.3.3 Strengthening Mechanism of Fiber Reinforced Composite 8 2.3.4 Dispersion Strengthening Mechanism of Strengthened
Composite
9
2.3.5 Strengthening Mechanism of Particulate Composite 9
2.4 Machining 10
vi 2.4.2 Classical Metal Machining Process 11
2.4.2.1 Orthogonal Cutting System 11
2.4.2.2 Oblique Cutting System 12
2.5 Milling 13
2.5.1 Peripheral Milling 14
2.5.2 Face Milling 16
2.5.3 End Milling 17
2.5.4 Fundamentals of Milling Processes 19
2.5.5 Cutting Parameter 20
2.6 Choosing the Process 22
2.6.1 CNC advantages and disadvantages 25
2.7 Surface Integrity 26
2.7.1 Surface and Subsurface Metallurgy 27
2.7.1.1 Surface Roughness 27
2.7.1.2 Natural Surface Roughness 29
2.7.1.3 Material Side Flow 30
2.7.1.4 Built-Up Edge 31
2.7.1.5 Subsurface Microstructure Alteration 32
2.8 Cutting tool 35
3.5 Experimental Equipment 43
3.5.1 3 Axis CNC Vertical Milling Machine 43
3.5.2 Surface Roughness Measurement 44
vii
3.5.5 Subsurface Microstructure 46
3.5.4 Polishing 47
3.5.4 Etching 48
CHAPTER 4: RESULT AND ANALYSIS
4.1 Introduction 50
4.2 Microstructure Aluminium LM6 before Machining 51
4.3 Parameter Selection 52
4.4 Surface Profile 55
4.5 Surface Roughness 58
4.6 Microstructure 61
4.7 Microhardness 63
CHAPTER 5: CONCLUSION AND RECOMENDATION
5.0 Conclusion 64
viii
LIST OF TABLE
2.1 CNC advantages and disadvantages 25
3.1 Chemical composition 39
3.2 Physical properties 40
3.3 Mechanical Properties 40
3.4 Initial cutting parameters 42
4.1 Cutting parameter selection using uncoated high speed steel 52
ix
LIST OF FIGURE
2.1 Electron configuration 4
2.2 Deformation of material in machining 10
2.3 Orthogonal cutting system 12
2.4 Oblique cutting system 13
2.5 Milling process on job part 14
2.6 Different Types of Peripheral Milling 15
2.7 Conventional Face Milling 16
2.8 Partial Face Milling 17
2.9 End Milling 17
2.10 Profile Milling 18
2.11 Pocket Milling 18
2.12 Surface Contouring 18
2.13 CNC Milling Machine 23
2.14 Coordinate System used in CN for Flat and Rotational Work 24
2.15 Definition of roughness average 29
2.16 Surface damage when a worn tool is used under dry-cut conditions 31 2.17 Plastic deformation at the cutting tool edge (The white dashed line is
the original tool profile)
32
2.18 The microhardness value measured beneath the machined surface 33 2.19 Effects of elevated temperature on strain hardened materials when
machining
34
3.1 Research methodology 38
3.2 Aluminium LM6 in ingot shape 41
3.3 High speed steel cutting tool 41
3.4 Uncoated carbide cutting tool 42
x 3.6 Surface roughness tester Mitutoyo SJ-301 44
3.7 Mitutoyo microhardness testing machine 45
3.8 Scanning electron microscope (SEM) 46
3.9 Surface grinding and polishing machine 47
3.10 Grinding paper 47
3.11 Etching solution for aluminium alloy 48
4.1 Microstructure of aluminium LM6 51
4.2 Cutting parameter experiment design 53
4.3 Surface profile using high speed steel 55
4.4 Surface profile using uncoated carbide 56
xi
LIST OF ABBREVIATIONS, SYMBOLS AND
NOMENCLATURE
Al - Aluminium
CNC - Computer Numerical Control
MMC - Metal matrix composites
CM - Centimetre
MM - Milimeter
> - More than
σ - Stress
τ - Torque
d - Diameter of milling cutter in mm
V - Cutting speed (linear) in meter per minute
N - Cutter speed in revolution per minute
Ra - Roughness average
Rv - Maximum depth
Rp - Maximum height
Rt - Total height
BUE - Built-up edge
xii
Min - Minutes
1
CHAPTER 1
INTRODUCTION
1.1 Background
Machining is a chip removal process to form a shape by using a specific machine. Machining is used because it has a high accuracy. By using this machine will also save time and production will rise higher. Machining refers to several processes such as sawing, drilling, boring, Shaping, reaming and others. There are various types of machining in manufacturing which lathe machine, milling machine, drill machine Presses and so on. Nowdays, a used machine is in automatic form. It is controlled by a computer program called numerical control (CNC). CNC is a command-based coordinate to get a form for you automatically (Kalpakjian 2006).
2 gives it many uses in the transport industry. Aluminium is so lightweight this means that less energy needs to be used to move a vehicle made with aluminium than one made from a heavier metal. Aluminium is also vital in power lines, the building and construction industry and commonplace household objects. The key features that lend aluminium to these uses are corrosion resistance, low density, ductility, electrical conductivity and strength in alloys (Davyson 2002).
Aluminium not only offers many advantages due to its material properties. Aluminium is also extensively adaptable to fabrication and machining processes. Aluminiun be used because aluminum is a very light metal. Aluminium also naturally generates a protective oxide coating and is highly corrosion resistant. Aluminium is an excellent heat and electricity conductor and in relation to its weight is almost twice as good a conductor as copper. This has made aluminium the most commonly used material in major power transmission lines. Aluminium is a good reflector of visible light as well as heat, and that together with its low weight, makes it an ideal material for reflectors in and aluminium also ductile and has a low melting point and density (Davyson 2002).
One of the common aluminium alloys is aluminium LM6. Aluminium LM6 is a high purity alloy, which is used in castings where thinner more intricate sections are required. Aluminium LM6 contains of copper, magnesium, silicon, iron, manganese, nickel, zinc, lead, tin, titanium and aluminium.This alloy has medium strength with excellent ductility but suffers a rapid loss of properties at elevated service temperatures (Sayuti 2008).
3 into surface integrity such as surface roughness, surface microhardness, subsurface micro structure and surface profile when machining aluminium LM6 using high speed steel and uncoated carbide cutting tools.
The research will create knowledge of machining characteristic of aluminium LM6. It will be beneficial in terms surface to the machinist whenever they want performing milling. The research also will provide useful information about suitable parameters to machinery aluminium LM6.
1.2 Objective
There are three main objectives by doing this project:
a) Identify the appropriate cutting parameter when machining aluminium LM6 using high speed steel and uncoated carbide cutting tools.
b) To investigate the characters of surface integrity when machining aluminium LM6 using high speed steel and uncoated carbide cutting tools.
c) To compare the surface roughness, surface microhardness, subsurface microstructure and surface profile.
1.3 Scope of Project
4
CHAPTER 2
LITERATURE REVIEW
2.1 Aluminium
Aluminium is a chemical element in the boron group with symbol Al. It is silvery white, and
it is not soluble in water under normal circumstances. Aluminium is a recyclable metal that is
lightweight, strong, and conductive. It is inexpensive and will not rust, nor will this natural
resource ever run out because to some extent, the earth's crust is made of it. It can be molded
into casts, worked with machine tools, and made into sheet metal, making it useful for a wide
variety of products (Kalpakjian 2006).
Figure 2.1: Electron configuration (Davyson 2002)
The mechanical properties depend not only on the purity of the aluminium but also upon the
amount of work to which it has been subject. Instead, it is found combined in over 270
different minerals including clay, bauxite, mica, feldspar, alum, cryolite, and the several
forms of aluminium oxide such as emery, corundum, sapphire, and ruby. Aluminium is
remarkable for its ability to resist corrosion and it is light weight. The yield strength of pure
aluminium is 7-11 MPa. Aluminium has about one-third the density and stiffness of steel yet
5 chief source of aluminium is bauxite ore. Structural components made from aluminium and
its alloys are vital to the aerospace industry and as we will find out are very important in
other areas of transportation and building. A range of tempers is thus produced by different
amounts of work hardening. It has an electrical conductivity about two-thirds that of copper
but weight for weight is a better conductor. Aluminium has a great affinity for oxygen and
any fresh metal in air rapidly oxidizes to give a thin layer of the oxide on the metal surface.
This layer is not penetrated by oxygen and so protects the metal from further attack.
Aluminum is the most heavily consumed non-ferrous metal in the world, with current annual
consumption at 24 million tons. About 75% of this total volume, or18 million tons, is primary
aluminum (that is, aluminum extracted from ore, as opposed to secondary aluminum which is
derived from scrap metal processing).
The process of primary aluminum production can be divided into three independent stages
which are, as a rule, carried out at different plants. These are:
• The actual mining of the necessary raw materials (bauxite and a variety of other
ores);
• The processing of the ore and preparation of aluminum oxide (alumina); • Production of primary aluminum from alumina.
2.2 Aluminium Alloy
6
resistance. The corrosion resistance properties of sheet alloy are improved by cladding it with layers of unalloyed aluminium (Kalpakjian 2006).
2.3 Metal Matrix Composites
7
2.3.1 Stir Casting Method of Fabrication of MMCs
Therefore a lot of fabrication technique in producing MMC Liquid state fabrication of Metal Matrix Composites involves incorporation of dispersed phase into a molten matrix metal, followed by its Solidification. In order to provide high level of mechanical properties of the composite, good interfacial bonding (wetting) between the dispersed phase and the liquid matrix should be obtained.
Wetting improvement may be achieved by coating the dispersed phase particles (fibers). Proper coating not only reduces interfacial energy, but also prevents chemical interaction between the dispersed phase and the matrix. The simplest and the most cost effective method of liquid state fabrication is Stir Casting (Kalpakjian 2006).
2.3.1.1 Stir Casting
Stir Casting is a liquid state method of composite materials fabrication, in which a dispersed phase (ceramic particles, short fibers) is mixed with a molten matrix metal by means of mechanical stirring. The liquid composite material is then cast by conventional casting methods and may also be processed by conventional Metal forming technologies.
Stir Casting is characterized by the following features:
• Content of dispersed phase is limited (usually not more than 30 vol. %).
• Distribution of dispersed phase throughout the matrix is not perfectly homogeneous:
o There are local clouds (clusters) of the dispersed particles (fibers);
o There may be gravity segregation of the dispersed phase due to a difference
8
• The technology is relatively simple and low cost.
Distribution of dispersed phase may be improved if the matrix is in semi-solid condition. The method using stirring metal composite materials in semi-solid state is called Rheocasting. High viscosity of the semi-solid matrix material enables better mixing of the dispersed phase.
2.3.2 Strengthening Mechanism of Composites
The strengthening mechanisms of the composites are different with different kind of reinforcing agent morphology such as fibers, particulate or dispersed type of reinforcing elements.
2.3.3 Strengthening Mechanism of Fiber Reinforced Composite
