Surface Integrity of Aluminium Lm6 Alloy When Machine with the High Speed Steel and Uncoated Carbide Cutting Tool.

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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)

NORAINI BINTI SULAIMAN

B051010241

891122045074

Faculty of Manufacturing Engineering 2013

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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:

NO. 86 JALAN BERTAM JAYA 4 TAMAN BERTAM JAYA

76450 MELAKA

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Disahkan oleh:

Cop Rasmi:

Tarikh: _______________________ ** Jika Laporan PSM ini SULIT at au TERHAD, sila lampirkan surat daripada pihak berkuasa/ organisasi berkenaan dengan menyat akan sekali sebab dan t empoh laporan PSM ini perlu dikelaskan sebagai SULIT at au TERHAD.

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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 : ………

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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:

………

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ABSTRAK

Pemesinan adalah satu proses untuk membentuk sebelum menghasilkan produk. Penggunaan pemesinan berkelajuan tinggi secara automatik menjana banyak hasil dan kualiti yang baik. Untuk menghasilkan keputusan yang baik perlu diambil kira beberapa perkara termasuk kelajuan pemotongan, kedalaman potong dan kadar suapan. Gunakan kelajuan pemotongan yang tinggi, kedalaman pemotongan dan kadar suapan akan meninggalkan kesan pada permukaan bahan kerja.Pemotongan pemilihan adalah juga penting untuk memastikan permukaan bahan kerja sentiasa dalam keadaan baik. Dalam kajian ini, bahan yang akan digunakan adalah Aluminium aloi LM6. Walau bagaimanapun, kebanyakan penyelidikan sebelumnya pada aluminium LM6 hanya memberi tumpuan kepada proses melarik sahaja. Penggunaan aluminium aloi LM6 adalah terhad sama sekali. Memandangkan mesin pengisar adalah antara alat yang paling serba boleh dan berguna dan juga mampu untuk menghasilkan profil dan pelbagai permukaan melengkung, kajian pengilangan aluminium adalah penting untuk menentukan alat yang betul memotong, parameter dan parameter pemotongan. Oleh itu, pemilihan mata pemotong yang betul juga memainkan peranan bagi penghasilan permukaan. Kajian ini memberi tumpuan lebih kepada integriti permukaan seperti kekasaran permukaan, kekerasan permukaan, profil permukaan dan mikro suktur permukaan. Pemilihan mata pemotong, masa pemotongan serta parameter yang sesuai juga memainkan peranan bagi penghasilan permukaan yang baik.

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ABSTRACT

Machining is a process to form before producing a product. Use of high-speed machining automatically generates a lot of revenue and quality. To produce good results should be taken into account a number of things including cutting speed, depth of cut and feed rate. Use of high cutting speed, depth of cut and feed rate will leave an impression on the surface of workpiece. Selection cutting is also important in order to keep the surface of the workpiece. In this study, material that will be use is Aluminum LM6 alloy. However, most of the previous researches on aluminium LM6 are focusing on turning and casting only which means there are limitation trials regarding milling process. Since millings are among the most versatile and useful tools and also capable to produce various profiles and curved surfaces, the study of aluminum milling is important to determine the right cutting tool, parameter and cutting parameter. Therefore, selecting the right cutting tools also play a role in the production of the surface. This research focuses more on the integrity of the surface such as surface roughness, surface hardness, surface profile and surface microstructure. Selection of cutting tools, cutting time and the appropriate parameters also play a role in producing a good surface.

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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.

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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.

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TABLE OF CONTENT

Abstrak i

Abstract ii

Dedication iii

Acknowledgement iv

Table of Content v

List of Tables viii

List of Figures ix

List Abbreviations, Symbols and Nomenclatures xi

CHAPTER 1: INTRODUCTION

1.1 Background 1

1.2 Objective 3

1.3 Scope of Project 3

CHAPTER 2: LITERATURE REVIEW

2.1 Aluminium 4

2.2 Aluminium Alloy 5

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

2.3.5 Strengthening Mechanism of Particulate Composite 9

2.4 Machining 10

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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

2.9 Sumarry 36

CHAPTER 3: METHODOLOGY

3.1 Flow Chart 38

3.2 Workpiece 39

3.2.1 LM6 - Aluminium Casting Alloy 39

3.3 Cutting tool 41

3.4 Cutting Condition 42

3.5 Experimental Equipment 43

3.5.1 3 Axis CNC Vertical Milling Machine 43

3.5.2 Surface Roughness Measurement 44

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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

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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

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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)

2.18 The microhardness value measured beneath the machined surface 33 2.19 Effects of elevated temperature on strain hardened materials when

machining

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

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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

4.5 Graph for surface roughness versus radial depth of cut 59 4.6 Graph for time versus radial depth of cut 59 4.7 Microstructure when aluminium LM6 machine 61 4.8 Microstructure when aluminium LM6 machine with uncoated carbide 62 4.9 Hardness value after machining aluminium LM6 63

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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

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xii

Min - Minutes

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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).

Physically, chemically and mechanically aluminium is a metal like steel, brass, copper, zinc, lead or titanium. It can be melted, cast, formed and machined much like these metals and it conducts electric current. In fact often the same equipment and fabrication methods are used as for steel (Boyer 2006). Pure aluminium is a weak, very ductile, material. 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. 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. One of the most common end users of aluminium is packaging, including drinks cans, foil wrappings, bottle tops and foils containers (Forbes 2001). Each of these relies on aluminium to provide a way of containing the food cleanly, and to protect it from changes in the local environment outside the packaging. Aluminium natural resistance to corrosion aids it in its role in packaging. Aluminium unbeatable strength to weight ratio

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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).

There is established study of machinery aluminium LM6 particularly in machining process. Many researcher have report that the characteristic of machinery of this material in turning process. However, there is limitation knowledge about machining aluminium LM6 especially in milling operation and by using the commercial cutting tool such as high speed steel and uncoated carbide. Milling process is important to produce a flat shape such as flat bar, vise and many more (Joardar 2011). Therefore the study of milling aluminium LM6 tends to investigate the machinability of aluminium LM6 in term of the cutting tool, the cutting parameters and the surface integrity. This report will focus more

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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

This project will be focus on identifying the surface integrity when machining aluminium LM6. On this project milling machine will use to machine the material. By using a different type of cutting tool such as high speed steel and uncoated carbide with the different cutting parameter the surface integrity will get the different result. The result will plot on a graph scratch after the testing has been done. Refer to the result conclusion will be make to make sure the surface integrity for LM6 are suitable in milling machinery.

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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 it is ductile, and easily machined, cast, and importantly in this piece is easily extruded. The

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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

Aluminiun normally is not stable to machining on the properties is not adequate enough to caters all process. Therefore, it’s normally been alloyed to get the best chateristic of all alloying properties. Aluminium alloy can be divided into two groups, wrought alloys and cast alloys. Each of these can be divided into two further groups: those alloys which are not heat treatable and those which can be heat treated. The non-heat treatable alloys have their properties controlled by the extent of the working to which they are subject. A range of tempers is thus produced. The heat-treatable alloys have their properties controlled by heat treatment. Like aluminium, the alloys have a low density, good electrical and thermal conductivity and a high corrosion

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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

One of the techniques to alloy the aluminium is to combine the materials with composite. This called metal matrix composites (MMC). Metal matrix composites are engineered materials combining two or more materials, one of which is a metal, where the tailored properties can be attained by systematic combination of different constituents. A variety of methods available for producing these advanced materials include the conventional casting process which is considered as the easiest processing technique. Preparation of these composite materials by foundry technology has the unique benefit of near-net shape fabrication in a simple and cost-effective manner. Besides, casting processes lend themselves to manufacture large number of complex shaped components of composites at a faster rate required by the automotive, transportation, sports and other consumer oriented industries. Metal matrix composites (MMC) are composed of an elemental or alloy matrix in which a second phase is embedded and distributed to achieve some property improvement. Based on the size, shape and amount of the second phase, the composite property varies. Particulate reinforced composites are often called as discontinuously reinforced metal matrix composites, constitute a large portion of these new advanced materials. The microstructures of the processed composites influence and have a great effect on the mechanical properties. Metal matrix composites (MMC) are considered as potential material candidates for a wide variety of structural application in the transportation, automobile and sport goods manufacturing industries due to the superior range of mechanical properties they possess (Hasyim 2002). MMCs combine metallic properties of matrix alloys (ductility and toughness) with ceramic properties of reinforcements (high strength and high modulus), leads to greater strength in shear and compression and higher service-temperature capabilities (Clegg 1997).

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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

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• 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

In such type of composite the reinforcing phase carries the bulk of the load and the matrix transfers the load to the reinforcing phase by the mechanism of seam. The high strength of the reinforcing phase restrict the free elongation of the matrix especially in its vicinity, whereas later is free to elongate at some distance away from the former. This type of non uniform deformation of the matrix leads to a shear stress at the matrix reinforcement interface which results tensile stress at the reinforcing phase. Thus the stress is transferred to the reinforcing phase. The fibers either may be continuous or discontinuous in the matrix. In the former case the load is directly applied to the reinforcing phase and stress is constant over its entire length. In case of discontinuous fibers, the stress in the fiber increased from zero value at the end to a maximum value in the centre and thus average tensile strength developed is always less than those of continuous fibers. For the same when the fracture of the reinforcing phase, therefore the strength of the discontinuous fiber reinforced composite increases with increasing the length of the fiber and artifacts that of the continuous fiber

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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

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CHAPTER 2

LITERATURE REVIEW

2.1 Aluminium

Figure 2.1: Electron configuration (Davyson 2002)

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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

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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

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2.3.1 Stir Casting Method of Fabrication of MMCs

2.3.1.1 Stir Casting

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

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• The technology is relatively simple and low cost.

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

Surface Integrity of Aluminium Lm6 Alloy When Machine with the High Speed Steel and Uncoated Carbide Cutting Tool.

UNIVERSITI TEKNIKAL MALAYSIA MELAKA