UNIVERSITI TEKNIKAL MALAYSIA MELAKA
DESIGN AND ANALYSIS OF CASTED LM6 - TIC IN
DESIGNING OF PRODUCTION TOOLING
This report submitted in accordance with requirement of the Universiti Teknikal Malaysia Melaka (UTeM) for the Bachelor Degree of Manufacturing Engineering
(Manufacturing Design) (Hons.)
by
ROHAYA BINTI DALI B051010165 880116 – 09 – 5194
UNIVERSITI TEKNIKAL MALAYSIA MELAKA
BORANG PENGESAHAN STATUS LAPORAN PROJEK SARJANA MUDA
TAJUK: Design and Analysis of Casted LM6-Tic in Designing of Production Tooling
SESI PENGAJIAN: 2012/13 Semester 2
Saya ROHAYA BINTI DALI
mengaku membenarkan Laporan PSM ini disimpan di Perpustakaan Universiti Teknikal Malaysia Melaka (UTeM) dengan syarat-syarat kegunaan seperti berikut:
1. Laporan PSM adalah hak milik Universiti Teknikal Malaysia Melaka dan penulis. 2. Perpustakaan Universiti Teknikal Malaysia Melaka dibenarkan membuat salinan
untuk tujuan pengajian sahaja dengan izin penulis.
3. Perpustakaan dibenarkan membuat salinan laporan PSM ini sebagai bahan pertukaran antara institusi pengajian tinggi.
(Mengandungi maklumat TERHAD yang telah ditentukan oleh organisasi/badan di mana penyelidikan dijalankan)
(TANDATANGAN PENULIS)
DECLARATION
I hereby, declared this report entitled “Design and Analysis of Casted LM6-TiC in Designing of Production Tooling” is the results of my own research except as cited
in the references.
Signature :
Author’s Name : Rohaya binti Dali
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 (Manufacturing Design) (Hons.). The member of the supervisory is as follow:
………
i
ABSTRAK
Peralatan pengeluaran merupakan salah satu elemen penting dalam industri pembuatan yang membantu dalam pengendalian sesuatu proses. Kebanyakan peralatan pengeluaran pada masa kini adalah kurang berpotensi dari segi kekuatan, berat, dan bahan yang digunakan untuk menghasilkan sesuatu peralatan memerlukan kos yang tinggi. Untuk menyelesaikan masalah ini, satu pendekatan melalui analisis campuran yang melibatkan 90% daripada aloi LM6 dan 10% daripada titanium karbida untuk mengetahui prestasi campuran bagi menggantikan bahan-bahan yang sedia ada dalam menyediakan peralatan pengeluaran. Tiga konsep rekabentuk acuan dilukis menggunakan perisian “SolidWork 2010” dan kemudiannya dianalisa melalui perisian ANSYS bagi mendapatkan keputusan persembahan campuran bahan tersebut di mana pengaliran bendalir lebur dalam proses tuangan dianalisa melalui
ii
ABSTRACT
iii
DEDICATION
iv
ACKNOWLEDGEMENT
First and foremost, I would like to express my heartily gratitude to my supervisor, Dr Taufik for his guidance and enthusiasm given throughout the progress of this project.
My appreciation also goes to my family who has been so supportive and understanding for all these years. Thanks for their encouragement, love and financial supports that they had been given.
Not to be forgotten to all the respondents that made this project successful. Thank you for their support and willingness to be part of this project.
v
List of Abbreviation, symbols and nomenclature xiv
vi 2.4 Material selection 25 2.4.1 Introduction of metal matrix composite 25 2.4.2 LM6 alloy (A413.2) 26
2.4.2.1 Introduction 26
2.4.3 Titanium carbide 29
2.4.3.1 Introduction 29
vii
2.5 Production tooling 32
2.6 Engineering analysis tools 32
CHAPTER 3 : METHODOLOGY 33
3.1 Flowchart of research activity 33
3.2 Phase 1: Design planning 35
3.2.1 Proposal 35
3.2.2 Literature review and patent search 35
3.2.3 Review input 35
3.3 Phase 2: Design proposal 36
3.3.1 Design of production tooling 36
3.3.2 The engineering sketch and detailed design 36
3.3.3 Sand casting technique 37
3.3.4 Material 38
3.3.5 Parameters of production tools 38
3.3.6 Documentation stage 38
3.4 Phase 3: Design simulation 40
3.4.1 Design simulation using ANSYS 40
3.4.2 Setting of ANSYS CFX 41 3.4.2.1 Import geometry 41 3.4.2.2 Meshing 43
3.4.2.3 Setup 44
viii
3.4.3 Setting of static structural analysis 50
3.5 Phase 4: Design selection 54
3.5.1 Design selection 54
3.6 Phase 5: Design presentation 54
3.6.1 Report writing 54
CHAPTER 4 : RESULTS AND DISCUSSION 55
4.1 Concept generation 55
4.1.1 Concept 1 56
4.1.2 Concept 2 56
4.1.3 Concept 3 57
4.2 Design selection 58
4.2.1 Simulation results 58
4.2.1.1 Static pressure 58
4.2.1.4 Turbulence kinetic energy 74
4.1.2.4.1 Comparison between concept 79
4.2.1.5 Wall shear stress 79
ix
4.3 Static structural analysis 82
4.3.1 Total deformation 84
4.3.2 Equivalent (von-mises) stress 84
4.3.3 Thermal strain 85
4.3.4 Factor of safety 86
4.4 Summary of result 87
CHAPTER 5 : CONCLUSION AND FUTURE WORK 89
5.1 Conclusion 89
5.2 Recommendation 90
REFERENCES 91
APPENDICES
x
LIST OF TABLES
2.1 Steps to the robust design of castings 15
2.2 Compositions of LM6 (%) 27
2.3 The properties of LM6 alloy 27
2.4 The properties of titanium carbide 30
3.1 4.1 4.2
Material properties
Ranking for three concepts Summary of FOS
xi
LIST OF FIGURES
2.1 Hierarchical classification of various casting processes 7
2.2 Sequence of sand casting process 9
2.3 2.4
Schematic illustration of a sand mould, showing various features Schematic illustrations of the sequence of operation for sand casting
Temperature as a function of time for the solidification of pure metals
Schematic illustration of three cast structure of metals solidified in a square mould
Microstructure of Al-Si alloy Flow chart of research activities
3D engineering drawing of production tool 2D engineering drawing of production tool Mould design of concept 1
Mould design of concept 2 Mould design of concept 3
xii
Velocity vector coloured by static pressure of concept 1 Graph static pressure of concept 1
Velocity vector coloured by static pressure concept 2 Graph static pressure of concept 2
Velocity vector coloured by static pressure of concept 3 Graph static pressure of concept 3
Graph comparison of static pressure and concept
Velocity vector coloured by velocity magnitude of concept 1 Graph velocity magnitude of concept 1
Velocity vector coloured by velocity magnitude of concept 2 Graph velocity magnitude of concept 2
Velocity vector coloured by velocity magnitude of concept 3 Graph velocity magnitude of concept 3
Graph velocity magnitude of concept 3
Velocity vector coloured by the internal energy of concept 1 Graph internal energy of concept 1
Velocity vector coloured by the internal energy of concept 2 Graph internal energy of concept 2
xiii
Velocity vector coloured by the internal energy of concept 3 Graph internal energy of concept 3
Graph comparison of internal energy and concept
Velocity vector coloured by the turbulence kinetic energy concept 1
Graph turbulence kinetic energy of concept 1
Velocity vector coloured by the turbulence kinetic energy concept 2
Graph turbulence kinetic energy of concept 2
Velocity vector coloured by the turbulence kinetic energy concept 3
Graph turbulence kinetic energy of concept 3
Graph comparison of turbulence kinetic energy and concept Velocity vector coloured by wall shear of concept 1
Velocity vector coloured by wall shear of concept 2 Velocity vector coloured by wall shear of concept 3 Graph comparison of wall shear and concept
xiv
LIST OF ABBREVIATIONS, SYMBOLS AND
NOMENCLATURES
ANSYS - Analysis System
FEA - Finite Element Analysis
FEM - Finite Element Method
FOS - Factor of Safety
IGS - Initial Graphics Specification
LM6 - Aluminium Alloy LM6
MMC - Metal Matrix Composites
SiC - Silicone Carbide
Ti - Titanium
TiC - Titanium Carbide
A - Area
P - Pressure
ρ - Density of fluid
xv
v - Velocity
Q - Volume rate
h - Distance
c - Friction factor
Re - Reynold number
D - Diameter
η - Viscosity
C - Constant
3D - 3 Dimension
1
CHAPTER 1
INTRODUCTION
This chapter explains what the entire project is about along with details on the background, purpose of this project, problem statement, objectives to be achieved, scope of project and project planning.
1.1 Introduction
2 Manufacturing industry in Malaysia mostly is based on automotive, food and drink, clothing, construction, electrical and electronics, metal, oil, rubber and so on. However, production tooling is one of the manufacturing industries also contributed to the economic growth of the country. According to the Maccarini et al. (1991), the tool itself can determine remarkable and unpredicted increases in the final cost of the product as a consequence of its reduced efficiency.
The eutectic aluminium silicon alloy or LM6 alloy is the near-eutectic group of ed silicon alloys has characteristics of low thermal expansion, excellent castability, high corrosion resistance, high abrasive wear resistance, good weldability, good thermal conductivity, and high strength at elevated temperatures (Hajjaj, 2007). In addition, according to Sulaiman (2008), LM6 alloy is a eutectic alloy having the lowest melting and the main composition is about 85.95% of aluminium and 11% to 13% of silicon.
The characteristic of titanium carbide which are wear-resistant, high temperature strength and refractory properties, useful in some applications, as examples are skins of space rockets, jet engine nozzles, combustion engines, radiation resistant first walls of nuclear reactors, armoring jackets, machine armors, metalworking tools, production tools and water-jet cutting nozzles. Due to its light weight, titanium carbide hard metals will be successfully used for the constructions of armor jackets and armors for airspace
machines if compared with hard metals based on tungsten carbide (Jalabadze et al., 2012).
3 However, the importance of the study is to examine the casted of LM6 and Tic to the production tooling in terms of low weight as well as low waste.
1.2 Problem statement
Production tooling at the moment is very vibrant and developing as high demand and positive feedback from users. There are several types of production tooling at present, which are vise, clamping, jigs, fixtures, and so on. Currently, production tooling is based on materials such as steel, metal, aluminium and so on. However, these materials are a high cost and relatively heavy to be used in the production tooling. Therefore, a number of improving materials such as metal matrix composite is to be used as an alternative material to replace current materials in the context of reducing the weight and waste of materials. The LM6 alloy and titanium carbide have better characteristic because both of the material are a part of reinforced material. However, the combination of LM6 alloy and titanium carbide is difficult to determine. Therefore, the study on the metal matrix composite in casting process must be further investigated in order to determine the performance of materials.
1.3 Objectives
These main purposes of this project are:
4
1.4 Scope of project
The production tooling is produced by implementing the sand casting process which is expendable mould but permanent patent, in which it is used of stir casting technique. The two materials of metal matrix composite which are LM6 (A413.2) and titanium carbide (Tic (IV) Carbide ALDRICH -325 mesh.98%) are used by mixed with percentage of 90 percent of LM6 and 10 percent of titanium carbide. Metal matrix composite acts as a fluid to form a pattern and sand silica acts as a solid material that serves as a mould in the analysis process later. In this project, a V-block jig acts as pattern of production tooling and drawn using SolidWork 2010. Only one pattern of production tooling is used however will be applied to three different concepts of mould pattern. The temperature rise or drop, pressure, mass flow rate and others analysis were carried out using ANSYS (Fluent) software. However, the Static Structural Analysis is used to determine the factor of safety (FOS).
1.5 Project Planning
5
CHAPTER 2
LITERATURE REVIEW
This chapter states about the data information gathered from previous research based on several sources that consist of journals, conference, books, and articles about the design and analysis of casted LM6-TiC in designing of production tooling. The topic that contains in this chapter consist of casting, sand casting, production tooling, metal matrix composite, LM6 alloy, titanium carbide, Solid Work 2010 software, Engineering Analysis Tools software and other related topic.
2.1 Casting
2.1.1 History
6 that was found in Mesopotamia about the date of 3200 BC. The state of Kamakura that located in Japan, about 1252 AD, some other casting product which is a colossal statue the Great Buddha completely produced using materials of tin. In the 14th century, he mentioned that from India and Middle East to Europe by way of Portugese explorers, the technology of casting was moved. Vannocio Biringuccio as the Head of Papal Foundry in Rome (around 1500 AD) regarded to be a father of the foundry industry in the West and had said “The art of casting… is closely related to sculpture … it is highly
esteemed… it is a profitable and skillful art and in large part delightful.”
2.1.2 Introduction
According to Gopinath and Balanarasimman (2012), the most ancient techniques used for manufacturing metal parts is a metal casting process where it is defined as the process to produce the desired shape of metal component parts by pouring the molten metal into the prepared mould (of that shape) and then allowing the metal to cool and solidify. It stated that the casting process is one of the fundamental types of manufacturing any type of products. Basically there are several basic operations in the process of casting that involves making the pattern, prepare the sand for moulding process, melting of metal pouring of models, cooling, shakeout, fettling, heat treatment, finishing and inspection. The main important role in the casting process is due to the solidification of liquid metal in the mould cavity such a phase change from liquid to solid which influence on the quality of the results in casting.
2.1.3 Types of casting
7 expandable mould, permanent mould and special processes and the details are shown in Figure 2.1.
Figure 2.1 Hierarchical classification of various casting processes (Ravi, 2004)
8 (a) Expendable mould
The moulds are usually made from sand, plasters, ceramics and similar materials and mixed with a variety of binders in order to improve the characteristics and the
The mould is made of the metals due to at high temperature and retains its strength. This type of mould will be used several times and design in simple in order to make the casting easy to take out and used for another casting. The mould advantages whereby it is better in heat conductors.
(c) Composites mould
The mould is made of various substances may be two or more that usually consist of sand, graphite, and metal and it has a permanent and an expandable portion that used to increase strength of mould, control the rates of cooling, and optimize the total investment or cost of the casting process.
2.2 Sand Casting
2.2.1 Introduction
9 sand casting is the one of the most versatile processes in manufacturing because it used of most metals and alloys with high melting temperatures involves iron, copper, and nickel. The steps of sand casting process are shown in Figure 2.2. Some types of process such as grinding, turning, milling, and polishing can be go through in order to remove the imperfections of surface or to add new features of casting product for better finishing.
Figure 2.2: Sequence of sand casting process (Kalpakjian and Schmid, 2010)
2.2.2 Sand Silica
Sand is one of the important elements in sand casting process and use as the main mould and core making material either for ferrous casting or non-ferrous casting. The physical and chemical properties of sand play the important role in the casting process and it
Placing a pattern in sand mould
Incorporating a gating system
Remove pattern and fill mould cavity with molten metal
Allow metal to cool until solidifies
Break away the sand mould
10 depends on the number of factors involves the metal and product being cast and also consider about the type of binder used (British Geological Survey, (n.d)). According to Kalpakjian and Schmid (2010), silica sand (SiO2) is mostly used as the mould material for sand casting process. The process to cast sand consist of preparation mould around the pattern, open the mould, remove the pattern, close the mould again and fill the cavity left in the sand with molten metal. Once the metal solidified, the mould will shake out and the duplicate pattern in metal is prepared (Ammen, 1979).
2.2.3 Types of sand mould
Three basic types of sand moulds in the sand casting process involves green-sand, cold-box, and no-bake moulds' (Kalpakjian and Schmid, 2010).
(a) Green sand mould
This is the inexpensive method of making mould due to the sand can be reused and most usual material used includes sand, clay and water. It is called as “green” because the sand in the mould is moist and because the character is high strength, generally used for large casting.
(b) Cold-box mould
This type of mould use binder which are organic and inorganic material that is blended into the sand for greater strength in order to bond the grains chemically. It is a more accurate dimension rather than green sand and it is high cost.
(c) No-bake mould
11
2.2.4 Pattern
According to Ammen (1979), a pattern can be defined as a shaped that form of wood or metal around which sand is packed in the mould and right after the pattern is removed the result cavity of casting is exactly like the shape of the project. It stated that in order to reduce and avoid any damage to the mould, the pattern must be designed to be easily removed and the pattern must be accurate in terms of the dimension and durable for the use intended. According to Kalpakjian and Schmid (2010), metal shrinkage, permit
There are many features in sand moulds, so that the system can function smoothly and each feature has its own role to enable the system to be fully functional as shown in Figure 2.3 (Kalpakjian and Schmid, 2010).
(a) Flask
It is functional as supporter to the mould that composed of cope (top) and drag (bottom) that separated by parting line and if there additional parts are called cheeks (more than two piece of mould).
(b) Pouring basin
Also known as pouring cup is functional as a guideline to pour molten metal into moulds.
(c) Sprue
12 (d) Runner system
It is responsible to flow the molten metal within the sprue into mould cavity by the channel and also the gates as the inlet sources.
(e) Risers
There are two kinds of risers which are blind riser and open riser that useful for casting due to it is supplying the additional molten metal as it shrinks during solidification.
(f) Cores
Cores are put into the mould to make a hollow shape which is inserted that made from sand. It is also applied on the outer of the casting to designing features such as deep external pockets.
(g) Vents
Vents placed in moulds that serve to release the gases from the reaction between the molten metal and the sand in mould and core. It is functional as exhaust air from the mould cavity.
Figure 2.3: Schematic illustrations of a sand mould, showing various features
13
2.2.6 Sand casting process
The cope and drag is closed, clamped, and weighted down when the mould has been shaped and the cores already located in the right place in order to avoid the separation of the mould when molten is poured into the mould cavity due to the exert pressure. It is very important to know how to conduct sand casting in order to come out with a good result and therefore whole steps of process in sand casting is shown in Figure 2.4 (Kalpakjian and Schmid, 2010).
a) Generate design for the pattern using mechanical drawing.
b-c) Mounted patterns on plates equipped with pins for alignment.
d-e) Core halves produce by core boxes.
f) Assembled core by placing the cope pattern plate to the flask and attach inserts to form the sprue and riser and secure by aligning pin.
g) The sand is rammed in the flask, and remove the plate and inserts. h) Produce the drag with the same way of core by inserting the pattern.
i) The pattern, flask, and bottom board are reversed, and the pattern is withdrawn, leaving the appropriate imprint.
j) The core is set in place within the drag cavity.
k) The mould is closed by placing the cope on top of the drag and securing assembly with pins.
l) Casting is removed after metal solidifies.
14
Figure 2.4: Schematic illustration of the sequence of operations for sand casting
(Kalpakjian and Schmid, 2010).
2.2.7 Design
2.2.7.1General Consideration for Casting
Table 2.1: Steps to the robust design of castings (Kalpakjian and Schmid, 2010).
Step Considerations
1 Design the shape of the part that easily cast.
15 mechanical properties and other related matters.
3 Locate the parting line of the mould in the part.
4 Locate and design the gates to allow uniform feeding of the mould cavity with molten metal.
5 Select appropriate runner geometry of the system. 6 Locate mould features such as sprue, screen ad risers. 7 Make sure proper controls and good practice is in place.
2.2.7.2 Casting consideration
Basically, casting process starts by transferring the molten metal into the patterned mould, which is patterned by the part that needs to be manufactured, thus allowing it to solidify. The part then, removed from the mould. There are several important considerations in casting operation in order to reduce the defects that greatly affect the casting results (Kalpakjian and Schmid, 2010).
(a) Solidification of Metals
Throughout the solidification and cooling to ambient temperature of the metal, series of event takes place. Molten metal that was poured into a mould will be influenced for its size, shape, uniformity, and chemical composition of the grains which also will influence the overall properties of the metal. Some several factors that causes of the events are types of metal, the thermal properties, the connection between volume and surface areas of casting in terms of the geometric form, and also the shape of the mould.
i) Pure Metals
16 grains occur when the metal cools rapidly and produced shell as Figure 2.6b. While columnar grains grown in orientation opposite to the direction of the heat transfer as Figure 2.6c.
Figure 2.5: Temperature as a function of time for the solidification of pure metals
(Kalpakjian and Schmid, 2010).
Figure 2.6: Schematic illustration of three cast structures of metals solidified in a square mould:
(a) Pure metals; (b) solid-solution alloys; and (c) structure obtained by using nucleating agents
17 (b) Fluid Flow
Fluid flow is one of important factor in the casting process whereby, the basic principles for the fluid flow of the gating design applies the Bernoulli’s theorem and mass continuity (Kalpakjian and Schmid, 2010).
i) Bernoulli’s Theorem
The principle conversation of the fluid elevation at any location in the system can be expressed by:
(2.1)
Where;
h – Elevation above a certain reference level p – Pressure at that elevation
– Density of the fluid g – Gravitational constant
v – Velocity of the liquid at that elevation
Subscripts 1 and 2 represent two different locations in the system.
ii) Mass Continuity
The law of mass continuity states that the rate of flow is constant whereas the liquids are incompressible and in a system with impermeable walls expressed in:
Q = A1v1 = A2v2 (2.2)
Where;
Q - Volume rate of flow (m3/s)
A – Cross sectional area of liquid system
v – Average velocity of the liquid in that cross-section
18 iii) Sprue Design
Assuming that the pressure at the top of the sprue is equal to the pressure at the bottom and there are no frictional losses, the relationship between height and cross sectional area at any point in the sprue can be expressed by:
√
(2.3)
Where;
Subscript 1 denotes the top and 2 denotes the bottom of the sprue.
iv) Modelling
Modelling of mould filling obtained by the equation of the molten metal s’ velocity while leaving the gate:
√ (2.4)
Where;
h – Distance from the sprue base to the liquid metal height c – Friction factor
v) Flow characteristics
Fluid flow in gating systems has to consider the presence flow of liquid either turbulence or laminar. To define the types of flow, Reynolds number (Re) is used as expressed by:
19 Where;
v – Velocity of the liquid D - Diameter of the channel
– Density of the liquid - Viscosity of the liquid
(c) Fluidity of Molten Metal
Fluidity is defined as the capability of molten metal to fill the mould cavities whereas the characteristics of molten metal and casting parameters are the two basic factors considered (Kalpakjian and Schmid, 2010).
i) Viscosity
When the viscosity increased, the fluidity of molten metal decreased.
ii) Surface tension
High surface tension of the liquid metal can reduce the fluidity.
iii) Inclusions
Inclusions are insoluble and have a significant adverse effect on fluidity.
iv) Solidification pattern of the alloy
The way molten metal solidifies affect the fluidity.
v) Mould design
Fluidity of molten metal influenced based on the design and dimension of sprue, runners, and the riser.
vi) Mould material and its surface characteristics
20 vii)Degree of superheat
Superheat improves fluidity by delaying solidification.
viii) Rate of pouring
Fluidity decrease as the pouring rate of molten metal is reduced because of the higher rate of cooling.
(d) Heat Transfer
21 (a) Start with a good quality melt
It is a requirement that either the process for the production and treatment of the melt hall have been shown to produce good quality liquid, or melt should be demonstrated to be of good quality.
(b) Avoid turbulent entrainment of the surface film on the liquid
Since for most liquid metal the maximum meniscus velocity is approximately 0.5 ms-1, the flow of molten metal should not go too fast. This maximum velocity may be raised in constrained by running systems or thin section of castings. This requirement also implies that the liquid metal must not be allowed to fall more than the critical height of a sessile drop of the liquid metal.
(c) Avoid laminar entrainment of the surface film on the liquid
This is the requirement that no art of the liquid metal front should come to a stop prior to the complete filling of the mould cavity. This is achieved by the liquid front being designed to expand continuously.
No feeding uphill in larger section thickness castings because of unreliable pressure gradient and complications introduced by convection.
22 (h) Reduce segregation
Predict segregation to be within limits of the specification desired.
(i) Reduce residual stress
No quenching in water following solution treatment of light alloys.
(j) Provide location points
All castings to be provided with agreed location points for pickup for dimensional checking and machining.
2.2.7.4Casting defects
According to Campbell (2004), some types of defects can often resemble each other in appearance and separating it is often difficult. There are several types of casting defect explain details as below:
(a) Fin
Caused by cope and drag are cracked, flasks are wrecked, inadequate cope or drag depth, and improperly rubbed at the bottom board.
(b) Rough surface
Caused by too coarse of sand, inadequate mould or core coating, finishing improper, the pattern is soiled.
(c) Blows
23 (d) Pin hole
Caused by the surface pitted with pin holes
(e) Shrink
Caused by the depression on casting surface due to the metal shortage
(f) Gas porosity
Caused by the absorption of gasses in metal melting
(g) Hot tears
Caused by too high a hot strength of the core or moulding sand.
(h) Cold Shot
Caused by the mould cannot fill faster due to some problem of too cold metal poured too slow and improper design of gating system.
(i) Misrun
Caused by cold metal, slow pouring, inadequate hydrostatic pressure, and humidity
(j) Run Out
Ramming sand caused a section of the mould being forced away from the pattern.
(k) Inclusions
Failure to keep the choke constant when pouring, moulding is soiled, and improper blow out mould before closing
2.3 Stir Casting Technique
24 spray decomposition and powder metallurgy. Stir casting is one of the techniques that used for mixing the material of metal matrix composite along with natural fiber composite and stirring to get the suitable dispersion (Naher et al., 2004).
However, according to Hashim (2001) generally stir casting method combine the selected matrix material and reinforcement material to be melted and the dispersion of the reinforcing material. Stirring causes to form a vortex where the reinforcing particles are introduced through the side of the vortex. When the slurry viscosity is increased, the air will entrap in the mould and it is very hard to remove.
On the other hands, according to Ravi et al. (2007), stir casting route is very economic and commercial process in order to produce the large size shape of composite casting or ingots that needs to be gone through secondary processing such as rolling, extrusion and forging.
In addition, Prabu et al. (2006) stated that stir casting is a method that is preferable to be applied in the industry due to simplicity, flexibility and most economic in fabricating large sized of components. However, technology of casting having several technical challenges currently exists and require attention are:
(a) Wettability between the particles and matrix.
The problem of the wetting of the ceramic by molten metal is one of surface chemistry and surface tension. According to Hashim et al. (1999), the way to improve wetting can be done through the rise up the solid surface energies, reduce the liquid matrix alloy surface tension and reduce the particles-matrix interface.
(b) Porosity in the cast metal matrix composites.
25 entrapment during mixing, evolution of hydrogen and shrinkage during solidification. Basically the porosity cannot be avoided but it can be controlled during the casting process.
(c) The reinforcement material and the matrix alloy chemical reactions.
According to Prabu et al. (2006), the microstructure and hardness of casting influenced by the speed of stirring and time of stirring. When increased the stirring speed, the non-uniformity occurred due to porosity, oxide skins, and gas formation at higher stirring speeds. As a result, when the speed and time of the stirring process increased, it resulted in a good hardness composite.
2.4 Material Selection
2.4.1 Introduction of Metal Matrix Composite
According to Kalpakjian and Schmid (2010), metal-matrix composite and ceramic-matrix composites is derived from a mixture between two or more chemically distinct and insoluble phases with a known interface. In an industry of aircraft, space vehicles, satellites, offshore structures, piping, electronics, automobiles, boats, and sporting goods, the application of these materials substantially improves the strength, stiffness, and plastics creep resistance.
26 structural efficiency, metal matrix composite becomes attractive to be implemented in industry and consider as versatile engineering materials.
The advantages of a metal matrix composite rather than a polymer matrix due to the characteristic which are the elastic modulus is higher, toughness, ductility, and at elevated temperatures it higher resists. However, the material has restricted that consist of the density is high and difficult in processing parts. Usually metal matrix composite is aluminium, aluminium-lithium alloy, magnesium, copper, titanium, and superalloys (Kalpakjian and Schmid, 2010).
2.4.2 LM6 alloy (A413.2)
2.4.2.1Introduction
As the name implies, silicon is the main alloying element in aluminium silicon alloys. The material also known as LM6 alloy that sometimes called piston alloy is one of near-eutectic group that having some common features such as low thermal expansion, very good castability, elevated corrosion resistance, elevated abrasive wear resistance, good weldability, good thermal conductivity, high strength at elevated temperatures and excellent corrosion resistance. Based on the capability, they are able to implement in industries such as applications of aerospace structure, industry of automobile, applications of military, and some several industries that related (Hajjaj, 2007).
27
Table 2.2: Compositions of LM6 (%)
The properties of LM6 alloy as shown in Table 2.3.
Table 2.3: The properties of LM6 alloy (CES Edupack (2010) and Hamouda et. Al (2007)).
Properties Description
Composition in detail Al (aluminium) 88%
Si (silicon) 12%
Young’s modulus 7.3e10 Pa
Shear modulus 2.7e10 Pa
Yield strength (elastic limit) 1.38e8 Pa
Tensile strength 2.89e8 Pa
Compressive strength 7.99e7 Pa
Flexural strength (modulus of rupture) 7.99e7 Pa
Elongation 0.0296
28 Fatigue strength at 10^7 cycles 4.08e7 Pa
Fatigue strength model (stress range) 3.55e7 Pa
Fracture toughness 2.65e7 Pa.m^0.5
Melting point 570 °C
Maximum service temperature (Tmax) 161 °C Minimum service temperature (Tmin) -273 °C
Thermal conductivity 142 W/m.°C
Specific heat capacity 963 J/kg.°C
Thermal expansion coefficient 2e-5 strains/°C
Latent heat of fusion 3.88e5 J/kg
Electrical resistivity 4.65e-8 ohms. m
Solidus temperature 574 °C
Liquidus temperature 582 °C
The maximum amount of silicon in cast alloys is of the order of 22% to 24% Si. However, increasing the amount of silicon may go as high as 40-50% Si if alloys made by powder metallurgy as well as strength increases at the expense of ductility (Hajjaj, 2007).
29
Figure 2.7: Microstructure of Al-Si alloys: (a) Hypoeutectic (1.65-12.6 wt% Si) 150x;
(b) Eutectic (12.6% Si) 400x; (c) Hypereutectic (> 12.6% Si) 150x. (Hajjaj, 2007)
2.4.3 Titanium carbide
2.4.3.1Introduction
Titanium, Ti is referring to name after the Greek god Titan is a silvery white metal discovered in 1791s and commercially produced in 1950s. Even the titanium is one of an expensive material, nevertheless the material mostly applied to industrial includes aircrafts, jet engines, racing cars, golf clubs, chemical, petrochemical, marine components, submarine hulls, armour plate, and medical applications due to the characteristic of material which is the highest strength weight ratio and resist corrosion at room (Kalpakjian and Schmid, 2010).
Titanium carbide content materials are used in rocket production, aircraft, nuclear power
and microelectronics industry. The probability of using titanium carbide is defined by a
complex variety of properties, one of them and the most important being structural
condition. The most promising is using of titanium carbide in micro-circuitry in the
electronic industry. Titanium carbide is one of the main constituents of hard metals. Role
of hard metals in modern technique cannot be overestimated, and, though tungsten
carbide is a leading in the industry of hard metals, but for many reasons titanium carbide
30 is deficient of elasticity can be solved if the hard metals are on nanocrystalline level, because physical-mechanical properties of nanocrystalline materials are much better
than of those with a crystalline structure. Nanocrystalline titanium carbide characterized
by excellent catalytic properties due to its light weight, titanium carbide hard metals will
be successfully used for the constructions of armour jackets and armour for airspace
machines if compared with hard metals based on tungsten carbide (Jalabadze, 2012).
According to Shyu and Ho (2006), metal matrix composites (MMC) such as carbides as a reinforced material under development of whiskers, monofilaments, fibre and particulates increasingly commercialized. As an example the application of implementation metal matrix composite in Toyota industry is then used in aluminium matrix composite in the development of diesel engine piston. Carbide-reinforced MMC which is a 6061 aluminium matrix reinforced with a percentage of 25 volume % of SiC particulate applied in flight production being another application of metal matrix composites.
The properties of titanium carbide are tabulated in Table 2.4.
Table 2.4: The properties of titanium carbide (CES Edupack (2010) and Saha et. al (1990)).
Properties Description
Density 4.91 kg/m^3
Price 79.2 USD/kg
Composition Ti/.97C
Base material Ti (Titanium)
Composition in detail C (carbon) 0.97%
Ti (Titanium) 99%
Young’s modulus 4.35e11 Pa
Shear modulus 1.76e11 Pa
31
Tensile strength 2.93e8 Pa
Compressive strength 2.93e9 Pa
Flexural strength (modulus of rupture) 3.52e8 Pa
Elongation 6.93e-4
Hardness - Vickers 2.77e10 Pa
Fatigue strength at 10^7 cycles 2.56e8 Pa
Fracture toughness 2.45e6 Pa.m^0.5
Melting point 3.21e3 °C
Maximum service temperature (Tmax) 862 °C Minimum service temperature (Tmin) -273 °C
Thermal conductivity 21.2 W/m.°C
Specific heat capacity 556 J/kg.°C
Thermal expansion coefficient 6.99e-6 strains/°C
Latent heat of fusion 1.16e6 J/kg
Electrical resistivity 2.11e-6 ohms. m
Solidus temperature 2153 °C
Liquidus temperature 2113 °C
2.4.3.2Application of titanium carbide uncoated steel races become the second generation. (Boving and Hintermann, 1990).
32 SiC or Ti composites are good candidates for the manufacture of fully bladed compressor rings (blings) because it capabilities of high temperature and the mechanical properties is performed well. The composite is used as a ring to carry out the very high hoop stresses raised in the disc and the titanium matrix enable to achieve 600 ◦C of operating temperature (Carrere et al, 2003).
2.5 Production Tooling
Production tooling is one of the important elements in production whereby it is used to keep the production going on well. Even the production tool was designed mostly in simple, but without the tools the production will face problems. There are several types of production tool; mostly used are jig, fixtures, vice, clamping and some other related tools that being used during production. It is important to make sure all tools are in good condition in order to reduce the impact of production.
2.6 Engineering Analysis Tools (FEA)
Historically, Finite Element Method was used in the late 1950’s and early 1960’s as a
tool to solve engineering problems commercially in industrial applications. In 1970’s
commercial programs started to emerge and at first FEM was restricted to costly mainframe computers belonging to the aeronautics, automotive, defence and nuclear industries and more companies started to use due to the usage have grown very rapidly. Few examples of available commercial programs consist of ABAQUS, FLUENT, Comsol Multiphysics, and ANSYS. However, ANSYS is a widely used commercial general-purpose finite element analysis program (KTH, Nd).
33
CHAPTER 3
METHODOLOGY
This chapter explains details on the development of the entire project via flow chart to illustrate the whole project. This chapter acts as a guideline in order to accomplish the project. This chapter involves the method of analysis, parameter to be determined and some other related matters.
3.1 Flowchart of research activity
34
35
3.2 Phase 1: Design planning
3.2.1 Proposal
This is the first step in which the title of the project is selected and then the subject is understood in detail to know the importance and purpose of the project. After finding out its purpose, it is easy to know what the purpose of the project is. The scope of the project will then determine the parameters to focus throughout the project.
3.2.2 Literature review and patent research
It is important to understand all the things related to the project to facilitate the process throughout the project, and managed successfully. As example, Chapter 2 is a literature review, in which each document or statements related to the project have been listed based on previous research of the smoothing out of the project and help to achieve the project objectives. Information obtained in each research is useful and can be used as a reference during the implementation of the project. However, search patent search is one of the resources that can help in the beginning of the process to design production tool where it is as a reference to find out if the product is designed to have existed or not.
3.2.3 Review design input
36
3.3 Phase 2: Design proposal
3.3.1 Design of production tooling
Production tooling is composed of clamping, vice, jigs, fixtures and others. The V-block jig was selected as the product throughout the implementation of this project, in which it is applied in the drilling process and serves to facilitate the process implemented.
3.3.2 The engineering sketch and detailed design
Only one production tool design is available but it differentiates on the mould design. Figure 3.2 shows the product 3D drawing using SolidWorks 2010.
Figure 3.2: 3D engineering drawing of production tool
37
Figure 3.3: 2D engineering drawing of production tool
3.3.3 Sand casting technique
38
3.3.4 Material
Metal matrix composite that consists of an aluminium silicon alloy or LM6 alloy (A413.2) and titanium carbide (TiC (IV) Carbide ALDRICH -325 mesh. 98%) is used as the main element of metal in the sand casting process. The materials are mixed together to generate data for comparison in order to select of the best and most suitable mould design based on analysis.
3.3.5 Parameters of production tools
Parameter setting is important to determine the best material choice and appropriate after obtaining the results of the analysis performed. Therefore, the parameters to be determined are, such as pressure, temperature rise or drop, mass flow rate, velocity, volume, solidification time, density and cost.
3.3.6 Documentation stage
39
Figure 3.4: Mould design of Concept 1
40
Figure 3.6: Mould design of Concept 3
3.4 Phase 3: Design simulation
A design for sand mould is generated Using SolidWorks 2010. The models are analysed by simulation via ANSYS Fluent software in order to determine the results based on the parameter set.
3.4.1 Basic Data to Be Used As Input for ANSYS FLUENT
41
Table 3.1: Material properties (CES Edupack 2010)
Properties
Specific heat capacity (J/kg-k) 922.3 691
Thermal conductivity (W/m-k) 129.92 145
Solidus temperature 727.9 -
Liquidus temperature 739.1 -
Melting temperature 519.45 -
3.4.2 Setting of ANSYS CFX
ANSYS software is finite element analysis (FEA) software used to simulate the characteristic of particles at a molecular level in a virtual space. The simulation result of ANSYS is similar to the real experiment generated. ANSYS can help to carry out the possible defects that may be a rise in the sand casting process.
3.4.2.1Import Geometry
42
Figure 3.7: Import geometry into ANSYS software.
43
Figure 3.8: Rename the surface as inlet and outlet.
3.4.2.2Meshing
The next step is meshing the 3D model by double click on the Mesh and Mesh Setup appeared. Select Mesh on Project tree and click generate Mesh icon. Set up the mesh same as in Figure 3.9 and then click Update icon.
44 The results of meshing are shown in Figure 3.10.
Figure 3.10: Results of meshing
3.4.2.3Setup
Next, click on the Setup icon and the FLUENT Launcher appeared. Just click on the OK icon to proceed to the next step. Fluid Flow (FLUENT) appeared and go through the problem setup first. Click on the General and select Transient under Solver and click the Check icon under Mesh. Then, click Models and setup same as Figure 3.11.
45 Go through the Materials under Problem Setup in order to set up the materials that had been mentioned previously and input the value of the density, specific heat, thermal conductivity, solidus temperature and liquidus temperature as shown in Figure 3.12.
Figure 3.12: Materials setup
46
Figure 3.13: Velocity Inlet setup
Figure 3.14: Velocity Inlet setup (temperature)
47
Figure 3.15: Pressure Outlet setup (momentum)
Figure 3.16: Pressure Outlet setup (thermal)
48
Figure 3.17: Wall setup (thermal)
Then proceed with the Dynamic Mesh by setup same as Figure 3.18.
Figure 3.18: Dynamic Mesh setup
49
Figure 3.19: Results
3.4.2.4Results
The last but not least is to view the result of the simulation. The flow results are observed by creating the streamline and the icon as shown in Figure 3.20.
Figure 3.20: Streamline icon
The streamline shows the flow of fluid throughout the mould cavity from the sprue until the riser and exit. The details of the flow of time in streamline 1(s) can be viewed by click on the Chart icon as shown in Figure 3.21.
50
3.4.3 Setting of Static Structural analysis
This analysis is continued from the ANSYS (FLUENT) by transfer the data to new in order to generate Static Structural analysis through select on the Result of FLUENT by right click and select the Transfer Data To New by choosing Static Structural same as Figure 3.22.
Figure 3.22: Starting of Static Structural analysis
51
Figure 3.23: Static Structural-Mechanical
Under the Project tree, determine the solid which is to define the material used for simulation as shown in Figure 3.24.
Figure 3.24: Select material
52
Figure 3.25: Force
Next, same as the step to select the force, select the thermal condition and identify the surface as shown in Figure 3.26.
Figure 3.26: Thermal Condition
53
Figure 3.27: Total deformation
Figure 3.28: Equivalent stress
Figure 3.29: Thermal strain
54
Figure 3.31: Safety factor (2 faces)
3.5 Phase 4: Design selection
3.5.1 Design Selection
In the design selection stage, the three concepts of the mould design that had been analysed was selected in terms of the performance regarding the static pressure, velocity magnitude, internal energy, turbulent kinetic energy, wall shear stress and others related parameter. The selection process was conducted through ranking concept in order to determine the most suitable mould design concept to be implemented in future.
3.6 Phase 5: Design presentation
3.6.1 Report writing
55
CHAPTER 4
RESULTS AND DISCUSSION
This chapter describes about the simulation analysis data and result for three design concepts of mould by using ANSYS software in details. There are three conceptual designs of mould whereby it different for position of sprue and riser that each of them was analysed. Based on the result and data, the ranking method was used to determine the best mould design that low weight as well as low waste in order to create the production tool designs that environmentally friendly.
4.1 Concept Generation
56
4.1.1 Concept 1
This concept consists of a sprue and a riser in order to guide the molten flow competently. The sprue and riser are located at the side of the cavity. 3D model of the molten flow was generated using SolidWorks 2010 in order to be used for the purpose of analysis in ANSYS software. Figure 4.1 shows the entire cavity of Concept 1.
Figure 4.1: Isometric view design Concept 1
4.1.2 Concept 2
57
Figure 4.2: Isometric view design Concept 2
4.1.3 Concept 3
This concept was similar to Concept 1, whereby it was different position of sprue and the riser. The sprue is located at the side of the cavity while the riser at the top of the cavity. 3D model of the molten flow is generated using SolidWorks 2010 in order to be used for the purpose of analysis in ANSYS software. Figure 4.3 shows the entire cavity of Concept 3.
58
4.2 Design Selection
4.2.1 Simulation Results
All the following results are totally generated using ANSYS (FLUENT) software. The steps of analysis data were clearly explained in Chapter 3. As the result of the analysis, the values of minimum and maximum of total pressure, velocity magnitude, internal energy, turbulent kinetic energy and wall shear stress was found. Besides that, the factor of safety (FOS) was carried out by using Static Structural analysis. Further explanations of the details analysis result were illustrated in this section.
4.2.1.1 Static Pressure
(a) Concept 1
59
Figure 4.4: Velocity vector coloured by static pressure of Concept 1
In Figure 4.5, the graph shows that the pressure was slightly higher at the sprue which mean at the starting point of molten flow. The pressure dropped rapidly right after 0.04 seconds and gradually decreases as well as the time progress until the pouring ends.
60 (b) Concept 2
Figure 4.6 shows the velocity vector coloured by the static pressure of Concept 2. The values of minimum and maximum total pressure of gating system were -16542.2 Pascal and 19884 Pascals. The figure shows at the starting point of pouring molten, it was very high pressure due to the location of sprue and cross sectional area decrease. While the metal entering the cavity, it shows some decreasing of pressure due to the spread area of molten flow was increased. However, the pressure still remains at high whenever reach to the riser and exit.
Figure 4.6: Velocity vector coloured by static pressure Concept 2
61
Figure 4.7: Graph static pressure of Concept 2
(c) Concept 3
62
Figure 4.8: Velocity vector coloured by static pressure of Concept 3
In Figure 4.9, the graph shows that the pressure was slightly higher at the sprue which mean at the starting point of molten flow. The pressure dropped rapidly right after 0.05 seconds at 7000 Pa. Then rise to 10000 Pa in 0.02 seconds and gradually decreases to -5000 Pa as well as the time progress until the pouring ends.
63
4.2.1.1.1 Comparison between concept
Based on the Figure 4.10, the graph shows that the highest static pressure was Concept 1 while the lowest was Concept 2. Basically, the lower static pressure was the better due to fewer defects occur in the process of casting. As the result, Concept 2 was chosen as the best concept in terms of the pressure.
Figure 4.10: Graph comparison of static pressure and concept
4.2.1.2 Velocity
(a) Concept 1
64
Figure 4.11: Velocity vector coloured by velocity magnitude of Concept 1
65
Figure 4.12: Graph velocity magnitude of Concept 1
(b) Concept 2
66
Figure 4.13: Velocity vector coloured by velocity magnitude of Concept 2
67
Figure 4.14: Graph velocity magnitude of Concept 2
(c) Concept 3
68
Figure 4.15: Velocity vector coloured by velocity magnitude of Concept 3
In Figure 4.16, the graph shows that the velocity has slightly increased from 0.5 m/s to 2.9 m/s in 0.05 seconds and decreased to 0.4 m/s in 0.08 seconds. However, the velocity starts to increase from 0.5 m/s to 2.4 m/s in 0.03 seconds and then decrease again as well as the time progress until the pouring ends.
Figure 4.16: Graph velocity magnitude of Concept 3
69 Based on the Figure 4.17, the graph shows that the highest velocity magnitude was Concept 1 and the lowest was Concept 2. According to Campbell (2004), filling of the mould can be carried out down, along, or up but along and up modes totally fulfil the non-surface turbulence condition. When the molten above the critical velocity, there was the danger of surface entrainment leading to defect create meanwhile below the critical velocity the melt was safe from entrainment problem. The maximum velocity condition effectively forbids top gating of castings because liquid aluminium reaches its critical velocity about 0.5 m/s after falling only 12.5 mm under gravity. Castings that never exceeded the critical velocity were consistently strong, with high fatigue resistance, and leak tight. He also stated that the experiment on casting aluminium have demonstrated that the strength of castings may reduce by as much as 90 percent or more if the critical velocity exceeded. As the result, Concept 2 was chosen as the best concept in terms of the velocity magnitude.
Figure 4.17: Graph comparison of velocity magnitude and concept
70 Figure 4.18 shows the velocity vector coloured by the internal energy of Concept 1. The values of minimum and maximum internal energy of gating system were 3280 J/kg and 503083.50 J/kg. From the figure, it shows that the internal energy at the starting point of molten flow was high. However, it was becoming lower when entering to fill the molten to entire cavity.
Figure 4.18: Velocity vector coloured by the internal energy of Concept 1
71
Figure 4.19: Graph internal energy of Concept 1
(b) Concept 2
72
Figure 4.20: Velocity vector coloured by the internal energy of Concept 2
In Figure 4.21, the graph shows that the internal energy was at 1e-02 J/kg and slowly decreased to 1e-3 J/kg as the completion of 250 iterations.
Figure 4.21: Graph internal energy of Concept 2
(c) Concept 3
73 and 502949 J/kg. From the figure, it shows that the internal energy at the starting point of molten flow was high in order to enter the cavity. However, it was becoming lower after entering to fill the molten to entire cavity and still remain until exit to the riser.
Figure 4.22: Velocity vector coloured by the internal energy of Concept 3
In Figure 4.23, the graph shows that the internal energy was at 1e-02 J/kg and slowly decreased to 1e-3 J/kg as the completion of 250 iterations.
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4.2.2.3.1 Comparison between concepts
Based on the Figure 4.24, the graph shows that the highest internal energy was Concept 1 and the lowest was Concept 2. Lower internal energy was the betterand it means that fewer energy that came out of the body. In accordance with the first law of thermodynamics, when a system undergoes a change of state as a result of a process in which only work was involved, the work was equal to the change in internal energy. As the result, Concept 2 was chosen as the best in terms the performance of internal energy.
Figure 4.24: Graph comparison of internal energy and concept
4.2.1.4 Turbulence kinetic energy
(a) Concept 1
75 entire cavity with lower kinetic energy and the value of the kinetic energy increase at the exit point due to the diameter of the riser was in small dimension.
Figure 4.25: Velocity vector coloured by the turbulence kinetic energyof Concept 1
In Figure 4.26, the graph shows that the turbulence kinetic energy does occur at the beginning of pouring the molten due to the changes of cross sectional area from large to small but it was considered as normal condition. However, the turbulence was at its peak at 0.19 seconds which is 0.38 m2/s2. The rest of molten flow was considered as smooth flow.
76 (b) Concept 2
Figure 4.27 shows the velocity vector coloured by the turbulence kinetic energy of Concept 2. The values of minimum and maximum turbulence kinetic energy of gating system were 4.77e-08 m2/s2 and 0.69 m2/s2. From the figure, it shows that the turbulence kinetic energy at starting point of pouring molten into sprue was very low but increase a bit at the entrance into mould cavity. The molten spread to entire cavity with lower kinetic energy until molten flow at the exit point near to riser located.
Figure 4.27: Velocity vector coloured by the turbulence kinetic energy of Concept 2
77
Figure 4.28: Graph turbulence kinetic energyof Concept 2
(c) Concept 3
78
Figure 4.29: Velocity vector coloured by the turbulence kinetic energy of Concept 3
In Figure 4.30, the graph shows that the turbulence kinetic energy does occur and its peak at 0.138 seconds which is 0.44 m2/s2. Even the turbulence occurs during the molten fill into the entire mould cavity, the amount was still minimal and consider as smooth flow of molten before solidification begins.
79
4.1.2.4.1 Comparison between concepts
Based on the Figure 4.31, the graph show that the highest turbulent kinetic energy was Concept 3 and the lowest was Concept 2. Lower kinetic energy was the better and it means that fewer energy that's lost from the body. As the result, Concept 2 was chosen as the best in terms the performance of kinetic energy.
Figure 4.31: Graph comparison of turbulence kinetic energy and concept
4.2.1.5 Wall shear stress
(a) Concept 1
Figure 4.32 shows the velocity vector coloured by the wall shear of Concept 1. The values of minimum and maximum wall shear stress of gating system were 0 Pa and 91.33 Pa. From the figure, it shows that the wall shear stress at starting point of pouring molten into sprue was very low but it was a bit high in the fillet area of the runner. It was remained low condition on wall shear stress during the molten spread to entire cavity. But increase a bit in the fillet area of the riser.
80
Figure 4.32: Velocity vector coloured by wall shear of Concept 1
(b) Concept 2
Figure 4.33 shows the velocity vector coloured by the wall shear of Concept 2. The values of minimum and maximum wall shear stress of gating system were 0 Pa and 30.85 Pa. From the figure, it shows that the wall shear stress at starting point of pouring molten into sprue was very low while entering the cavity and it was remain the condition during the molten spread to entire cavity and exit through the riser.
81 (c) Concept 3
Figure 4.34 shows the velocity vector coloured by the wall shear of Concept 3. The values of minimum and maximum wall shear stress of gating system were 0 Pa and 90.98 Pa. From the figure, it shows that the wall shear stress at starting point of pouring molten into sprue was very low but it was a bit high in the fillet area of the runner. It was remained low condition on wall shear stress during the molten spread to entire cavity. But increase a bit in the fillet area of the riser.
Figure 4.34: Velocity vector coloured by wall shear of Concept 3
4.2.1.5.1 Comparison between concept
82
Figure 4.35: Graph comparison of wall shear and concept
4.3 Static Structural Analysis
All the results of the static structural analysis were generated from the ANSYS software whereby the analysis was a continuation of the ANSYS (FLUENT). The best concept design that had been selected for further analyzed was Concept 2. The information from ANSYS (FLUENT) analysis was linked to the static structural analysis in order to proceed for the new simulation. The results of the static structural analysis were explained further details in the next section. In the analysis, the force applied to the surface area was 500 N as shown in Figure 4.36.
83
Figure 4.36: Applied force 500N
The thermal condition for this analysis was set to 22 °C as shown in Figure 4.37. It is because the V-block jig was applied as functional to clamp the workpiece in the drilling process in order to make holes or others required operation. There were two surfaces of V-block jig that was the most critical area.
84
4.3.1 Total deformation
Figure 4.38 shows the results of total deformation of static structural analysis. The values of minimum and maximum of total deformation were 157.61 m and 176.05 m. This means that the pattern can deform much.
Figure 4.38: Total deformation
4.3.2 Equivalent (von-Mises) stress
85
Figure 4.39: Equivalent (von-mises) stress
4.3.3 Thermal strain
Figure 4.40 shows the results of thermal strain of static structural analysis. The values of minimum and maximum of thermal strain were 0 m/m and 0 m/m.
86
4.3.4 Factor of safety (FOS)
(a) FOS of two faces
Figure 4.41 shows the results of safety factor for two faces selected. The values of minimum and maximum of safety factor was 15. It means that the design was good in terms of the factor of safety was higher than 1.
Figure 4.41: FOS for two faces
(b) FOS of all body
