Design And Optimization Of Runner And Gating Systems For The Permanent Mold Casting.
UNIVERSITI TEKNIKAL MALAYSIA MELAKA
DESIGN AND OPTIMIZATION OF RUNNER AND GATING
SYSTEMS FOR THE PERMANENT MOLD CASTING
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
MOHAMMAD AIZRULSHAH BIN KAMARUDDIN
B050910203
790407-01-6397
FACULTY OF MANUFACTURING ENGINEERING
2013
DECLARATION
I hereby, declared this report entitled Design and Optimization of Runner and
Gating for Permanent Casting is the results of my own research except as cited in
the references.
Signature
:
………………………………………….
Author’s Name
:
MOHAMMAD AIZRULSHAH BIN
KAMARUDDIN
Date
:
3.6.2013
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 committee is as follows:
----------------------------------------------------
ABSTRAK
Aliran bendalir memainkan peranan penting dalam menghasilkan acuan tuangan
yang berkualiti tinggi . Aliran bendalir
dipengaruhi oleh halaju tuangan
dan
pelari(runner) dan reka bentuk pintu (gating) acuan. Ia akan menentukan sama ada
aliran adalah gelora atau lamina. Proses reka bentuk adalah peringkat yang paling
penting dalam mana-mana pengeluaran produk yang sama seperti membuat acuan
kekal . Amalan semasa adalah kaedah cuba jaya untuk mendapatkan reka bentuk
acuan kekal yang terbaik. Dengan menggunakan perisian analisis cecair dinamik,
proses mereka bentuk pelari(runner) dan pintu (gating) boleh dipermudahkan.
Matlamat utama kajian ini adalah untuk mereka bentuk dan mengoptimumkan
pelari(runner) dan pintu (gating) untuk acuan tuangan kekal. Kaedah yang
digunakan dalam kajian ini adalah Solidworks 3D model dan ANSYS FLUENT
perisian pengiraan analisis bendalir dinamik. Model aliran gelora telah digunakan
untuk mensimulasikan aliran aluminium lebur LM6. Empat rekabentuk konsep telah
dianalisa oleh ANSYS FLUENT daripada segi tekanan statik, magnitud halaju,
tenaga kinetik bergelora, tenaga dalaman dan nombor sel Reynolds. Keputusan yang
diperolehi daripada simulasi dioptimumkan untuk mewujudkan acuan yang
sempurna. Kesimpulannya acuan kekal bagi proses acuan tuangan gravity telah
direka dan dioptimumkan dan ia telah memenuhi objektif projek. Analisis simulasi
adalah alat yang sangat berguna bagi jurutera yang boleh digunakan sebagai rujukan
untuk meningkatkan produktiviti dan kualiti produk, sistem atau proses.
i
ABSTRACT
Fluid flow plays a major role in producing good quality casting. The fluid flow is
influenced by the pouring velocity and the runners and gating design of the mold.
The design process is the most important stages in any product manufacturing same
as permanent mold making. The current practice is the experimenting method to
predict the best design. By using computational fluid dynamic analysis the process
of designing runners and gating can be improved. The main objective of this paper is
to design and optimize the runner and gating systems for permanent mold casting.
The method use in this paper is Solidworks 3D modeling and ANSYS FLUENT
computational fluid dynamic analysis software. Transient, turbulence flow model
has been applied to simulate the flow of molten aluminum LM6. The ANSYS
FLUENT analyzed 4 runners and gating design concept from the aspect static
pressure, velocity magnitude, turbulent kinetic energy, internal energy and cell
Reynolds numbers. The results gained from the simulation are optimized to create a
perfect mold. As a conclusion a permanent mold casting was designed and
optimized and it fulfilled the objective of the project. The simulation analysis is a
very powerful tool for engineers that can be used as a reference to improve
productivity and quality of product, system or process.
ii
DEDICATION
To beloved wife
Azlinda Mohamad
To my kids
Muhammad Izzu Syahmi and Maryam Kayyisah
And to my parents
Hj Kamaruddin Hj bin Hj Idris
Hjh Aisah binti Abu Bakar
iii
ACKNOWLEDGEMENT
I would like to thank my supervisor Dr Taufik for the support, guidance and
understanding during the making of this report. Thank to my wife Azlinda for the
patience and understanding. Thank also to my colleague for the idea, discussion and
encouragement.
iv
TABLE OF CONTENT
Abstrak
i
Abstract
ii
Dedication
iii
Acknowledgement
iv
Table of Content
v
List of Tables
viii
List of Figures
ix
CHAPTER 1: INTRODUCTION
1.1
Project Background
1
1.2
Problem Statement
3
1.3
Objective
3
1.4
Scope
3
1.5
Report Structure
4
CHAPTER 2: LITERATURE REVIEW
2.1
Casting And Its History
5
2.2
Permanent Mold Casting
8
2.2.1
9
Advantages Of Permanent Mold Casting
2.3.1.1.
Volume
9
2.3.1.2.
Tolerance and Surface finish
9
2.3.1.3.
Cost
10
2.2.2
Limitation Of Permanent Mold Casting
10
2.2.3
Defect In Permanent Mold
11
2.2.4
Permanent Mold Casting Process
13
2.3 Design
13
2.3.1 Rigging System Design
15
2.3.2 Riser Design
16
2.3.3 Feeding System In Riser Design
18
2.3.4 Gating
18
v
2.3.4.1 Gating Design Variables
19
2.3.4.2 Principle of fluid flow
20
2.3.4.3 Ideal gating design
22
2.3.5
Sprue Design
24
2.3.6 Runner Design
25
2.4
Pattern
26
2.5
Computer Aided Engineering
27
CHAPTER 3: METHODOLOGY
3.1
Project Planning
29
3.2
Overall Project Framework
29
3.2.1 Planning Stage
3.2.1.1.
Problem statement, objective and
scope of research identification
3.2.1.2.
31
Production tooling and
computational fluid dynamics
3.2.1.3.
31
31
Parameter permanent mold
design study
32
3.3.
Stage 2: The Design Stage
32
3.4.
Stage 3: Analysis And Result
34
3.5.
Stage 4: Report Preparation and Presentation
34
3.6.
The Design Concept Sketches
35
3.7.
Conclusion
36
CHAPTER 4: RESULT & DISCUSSION
4.1
The Design concept
37
4.1.1 Design concept 1
38
4.1.2 Design Concept 2
39
4.1.3 Design concept 3
39
Design concept 4
39
4.1.4
4.2
Ansys 14 Fluent Simulation
40
4.2.1 Ansys Fluent models
40
4.2.2 Ansys Fluent Material
40
4.2.2.1 Casting Material
40
vi
4.2.2.2 Wall Material
41
4.2.2.3 Cell Zone Condition
41
4.2.2.4 Boundary Condition
41
4.2.3 Ansys Simulation Result Data
43
4.2.3.1 Design Concept 1
43
4.2.3.2 Design Concept 2
47
4.2.3.3 Design Concept 3
52
4.2.3.4 Design Concept 4
57
4.3
Ranking
61
4.4
Optimization
63
4.4.1 The Runner And Gating Concept Design
63
4.4.2 Ansys Simulation Result Analysis
65
4.4.3 Ansys Fluent Flow Analysis Optimized
66
4.5
SolidWorks Modelling
70
4.6
Summary of Result
72
CHAPTER 5: CONCLUSION & FUTURE WORKS
5.1.
Conclusion
73
5.2.
Future works
74
REFERENCES
75
APPENDIX A
vii
LIST OF TABLES
4.1
LM6 Properties
41
4.2
Steel properties
41
4.3
The inlet Condition value
42
4.4
The outlet condition
42
4.5
Simulated Ansys Fluent data
43
4.6
Simulated Data
50
4.7
Simulated Data
55
4.8
Simulated Data
59
4.9a
Design 1 and 2 simulated data
61
4.9b
Design 3 and 4 simulated data
61
4.10
Maximum Value comparison
62
4.11
Ranking
62
4.12a Ansys Fluent Result for runner and gating optimize concept
66
4.12b Ansys Fluent Result for runner and gating optimize concept
66
4.13
70
Table of maximum value
viii
LIST OF FIGURES
1.1
Gooseneck Clamp
4
2.1
The important development in casting process
6
2.2
Expendable Mold process tree
7
2.3
Process tree under permanent mold casting. Yellow indicates the
8
scope of study
2.4
Approximate values of surface roughness and tolerance on
9
dimensions typically obtained with different manufacturing
processes. ECM, electro-chemical machining; EDM, electrical
discharge machining
2.5
Differences between manufacturing process
10
2.6a
Example defect in the casting process
12
2.6b
Example of common defects hot tear in casting. Which the
12
defect can be minimized or eliminate with proper design and
preparation of molds
2.7
Directional and progressive solidification in a casting equipped
17
with a riser
2.8
Basic component of a single gating system for a horizontal
19
parted mold
2.9
Schematic illustrating the application of Bernoulli’s theorem to a
22
gating system
2.10
Poor top gates and side-fed running system, compared with (b) a
23
more satisfactory bottom-gated and top-fed system.
ix
2.11
(c) Poor system gated at joint and (d) recommended economical
23
and effective system
2.12
Comparison of flow patterns in two vertical gating systems. (a)
24
Poorly designed system. (b) Properly designed system using a
tapered runner that equalizes flow through the ingates
2.13
Schematic showing the advantages of a tapered sprue over a
25
straight-sided sprue. (a) Natural flow of afree-falling liquid. (b)
Air aspiration induced by liquid flow in a straight -sided sprue. (c)
Liquid flow in a tapered sprue
2.14
Schematic illustrating fluid flow around right-angle and curved
26
bends in a gating system. (a) Turbulence resulting from a sharp
corner. (b) Metal damage resulting from a sharp corner. (c)
Streamlined corner that minimizes turbulence and metal damage
2.15
Goose neck clamp
2.16
Technical drawing and dimension of the gooseneck clamp
27
3.1
Project Framework Flow Chart
30
3.2
SolidWorks 3d modelling flow chart
33
3.3
Mold Design outline with SolidWorks
33
3.4
ANSYS 14 Fluent procedures flowchart
34
3.5
Sketch 1
35
3.6
Sketch 2
36
3.7
Sketch 3
36
3.8
Sketch 4
36
x
4.1
Design Concept 1
37
4.2
Design Concept 2
38
4.3
Design Concept 3
39
4.4
Design Concept 4
39
4.5
Contour of static pressure
43
4.6
Contour of velocity magnitude
44
4.7
Contour of turbulence kinetic energy
45
4.8
Contour of internal energy
45
4.9
Flow simulated
46
4.10
Temperature vs Time Chart
47
4.11
Contour of static pressure
48
4.12
Contour of velocity magnitude
49
4.13
Contour of turbulence kinetic energy
49
4.14
Contour of internal energy
50
4.15
Flow simulated
51
4.16
Temperature vs Time Chart
52
4.17
Contour of static pressure
53
4.18
Contour of velocity magnitude
53
4.19
Contour of turbulence kinetic energy
54
4.20
Contour of internal energy
55
4.21
Velocity Streamline Flow
56
4.22
Temperature vs Time Chart
56
xi
4.23
Contour of static pressure
57
4.24
Contour of velocity magnitude
58
4.25
Contour of turbulence kinetic energy
58
4.26
Contour of internal energy
59
4.27
Streamline Flow
60
4.28
Temperature vs Time Chart
61
4.29
Gating and runner optimized design 1
63
4.30
Gating and runner optimized design 2
64
4.31
Gating and runner optimized design 3
65
4.32
Ansys Fluent Streamline for optimized
66
4.33
Temperature vs Time Chart
67
4.34
Streamline Flow for concept 2 optimized
67
4.35
Temperature vs Time Chart
68
4.36
Streamline Flow for concept 3 optimized
68
4.37
Temperature vs Time Chart concept 3 optimized
69
4.38
Mold in close position
71
4.39
Mold Exploded view
71
4.40
Mold halves features
72
xii
CHAPTER 1
INTRODUCTION
This chapter discusses briefly the design and optimization of runner and gating
system for the permanent mold. This chapter of the report briefly discusses the
project background, problem statement, objective and scope.
1.1
Project Background
Casting is an economical and oldest manufacturing process in producing or
reproducing complex part in mass numbers. The first metal casting was found to be
made during the period from 4000 to 3000 BC using stone and metal to cast copper
and bronze (Kalpakjian and Schmid, 2006). Casting is a process in which molten
metal is poured into a cavity of a mold which are split or broken apart to extract the
solidified metal cast(Boothroyd et al. 2002). Designing a mold used in casting is
considered as an art and science. There is no exact formula or parameter can be
used. It depends on the mold designer experiences, trial and error. Casting is divided
into 2 categories which is non permanent and permanent molds. This report covers
the designing and the optimization of runner and gating system for permanent mold
casting.
Permanent mold casting is a method used to cast product or part using permanent
mold or non expendable mold unlike sand casting where the use of expendable mold
and the flows only at the force of gravity (Butler 1998). As the name implies non
1
expendable mold means that the mold is usually made from metal. The same
guidelines and rules use in designing a sand casting are applied in designing the
permanent mold. Except that in sand casting if there is an error or modification in
the design the mold can be crushed and reconstructed, this method did not apply to
permanent mold where it will require metal cutting and reshaping (Shamasundar et
al., 2010.). This will require cost therefore permanent mold need to be designed
carefully. Due to the material used for making the mold, it usually being used to cast
non ferrous alloy and some limited application for casting cast iron. Typical material
can be cast using permanent mold is aluminum, zinc, brass, copper, lead and even
gray cast iron. The benefit of using permanent mold casting is that the high
production runs due to faster cooling rate than sand. Permanent mold casting also
produces a product with high dimensional accuracy, near net shape and use less raw
material. Reasonable price cost can be achieved from the high production rate with
metal molds especially the water cooled molds compare to sand or investment
casting (Butler, 1998). Limitation of permanent mold casting is that not all shapes
can be cast using it, but with the combination of detachable and expendable core the
potential is limitless.
Defect effecting sand casting also applies to permanent mold casting such as
porosity and shrinkage.
In order to eliminate the defect, the mold to be designed
carefully. Design is the critical step in the development of cost effective, high
quality casting. In designing a good permanent mold the part geometry plays a big
role in effecting the load carrying functionality of the casting but also the mold
construction
(Stoll, 2009). The main purpose of designing the molds is to
concentrate liquid solid contraction until to the last portion of the casting to solidify
(Lampman,
2009). In the production of permanent mold the design or the
development stage use a lot of resources but quickly offset by the high production
run. A Goose neck machine clamps used for this study. Then the molds are design
using CAD software, the designed mold were tested using an analysis software.
Later the design will go optimization process. This project presents the design of
permanent mold use for casting a production tooling. The study on making a
permanent mold will give a lot in sight in the best method in the manufacturing of
the mold either using experimental or Computer Aided Engineering Software.
2
1.2
Problem Statement
Designing permanent molds for casting can be considered as
art and science.
Runners and the gating system are the most important part of the mold. There a
numerous guideline can be used for designing a mold but the position and size of the
runner and gating depended on the part want to cast. At the moment the current
practice in mold construction is an experimenting method where base on trial and
error. The trial and error method solely depended on the design engineers
knowledge and experience. However this practice is time consuming and high cost.
In this report the product use for study is a Goose neck machine clamp. Finding the
position and size of the runner and gating system is crucial to produce defect free
product and near net shape as possible. This project presents the design of
permanent molds, design and analyze using Computer Aided Engineering software.
1.3
Objective
1.3.1 To investigate the design parameter of a permanent mold casting for Goose
neck machine clamp.
1.3.2 To analyze and optimize the permanent mold casting Computer Aided
Engineering software.
1.3.3 To design a permanent mold casting for Goose neck machine clamp.
1.4
Scope
This report only focuses on mold design of a production tooling called Goose neck
machine clamp. The report also considers the existing optimum parameters for
casting molds. The mold geometry design using SolidWorks design software and
analyze using the ANSYS FLUENT software. The mold designed is for gravity
feed casting. Aluminum LM6 and stainless steel is use as the molten metal and mold
in the analysis.
3
Figure 1.1 Goose neck clamp
1.5
Report Structure
Chapter 1 describes the background of the study. Chapter 2 consists of the literature
review and chapter 3 the methodology of the research project. Chapter 4 explained
the result finding and chapter 5 the conclusion.
CHAPTER 2
LITERATURE REVIEW
This chapter consists of the information gathered regarding the project title which is
Design and optimization of runner and gating system for permanent mold casting.
The information collected from books and previous study. Tools and software used
in this project also will be explained in this report.
2.1 Casting And Its History
Casting can be considered as an oldest manufacturing method know to man. It's a
method used to produce parts in mass numbers. Casting was first used around 4000
B.C to cast ornament and copper arrow head (Kalpakjian and Schmid, 2006).
Copper is the first metal to be cast and usually the component made were weapon
arrow head or axes. During the Bronze Age (3000-1500 BC) alloys such as tin
bronze and arsenical copper were developed. Alloying, as well as reducing the
melting temperatures required, improved the strength of the finished product and
helped to oxidize the melt, enabling a better surface finish and higher level of detail
to be obtained because of the enhanced fluidity (Jolly 2003).
There some archeological find and the oldest casting in existence is a copper frog
dated 3200 BC discovered in Mesopotamia. One of the first cast iron objects, a 270
kg tripod, was cast by Chinese in 600 BC. A colossal statue of the Great Buddha in
tin lead bronze was completed in 1252 AD at Kamakura in Japan (Ratnakar, 2004).
5
There is also some archaeological evidence that the “lost
ost w
wax” process was
developed at about
bout the beginning of the Bronze Age. This method
hod was used to cast
small object mainly
nly jewelry (Jolly 2003). Later on this method
hod was renamed the
investment casting.. T
The figure 2.1 below show the important deve
velopment in casting
process.
Figure 2.1 The important development in casting process (Jolly
lly 2003).
6
Casting can be used to produce a wide variety of product with complex shape and it
only involves one major manufacturing method. Casting involves pouring molten
metal in a mold cavity that configured to the shape and dimension of the intended
finish product. Casting can be divided into 2 major categories which is expandable
and non expandable mold. Figure 2.2 below illustrates the process tree under the
expandable mold process
Expendable
mold
with permanent
patterns
Lost foam
Investment
casting
Replicast
process
Counter
gravity
with expandable
patterns
Bonded
sand
molding
Green Sand
CO2
Slurry
molding
Plaster
Rammed
graphite
molding
Ceramics
Nonbonded
sand molding
Vacuum
molding
Magnetic
molding
Resin
Bonded
Figure 2.2 Expendable Mold process tree
As the name implies the expendable mold process use material that are expendable
such as sand or other granular mold material. In expendable mold casting with
permanent pattern the mold needed be split into in order to remove the pattern
before the actual pouring process is done. Due to the title of the project the
expendable mold will not be explained further.
7
2.2 Permanent Mold Casting
Permanent mold casting is a casting process that uses non expendable that are either
made from metal or graphite. Permanent mold processes involve the production of
castings by pouring molten metal into permanent metal molds using gravity, low
pressure, vacuum or centrifugal pressure and simple reusable cores are usually
made of metal (Lampman, 2009). The mold cavity and the gating system are
machined into the mold and become an integral part of the mold (Kalpakjian and
Steven, 2006). That's why the design of the mold is crucial. Figure 2.3 illustrated the
process tree under permanent mold casting process.
Permanent mold
permanent and
semi permanent
mold
Gravity permanent
mold
High pressure die
casting
low pressure
permanent mold
Conventional high
pressure die
casting
Static pour
permanent mold
Convetional Low
pressure
Squeeze Casting
Tilt mold
permanent mold
Vacuum/pressure
riserless
Semisolid
processing
Pressure/ couter
pressure
Vacuum Die
casting
Figure 2.3 Process tree under permanent mold casting. Yellow indicates the scope of study.
8
DESIGN AND OPTIMIZATION OF RUNNER AND GATING
SYSTEMS FOR THE PERMANENT MOLD CASTING
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
MOHAMMAD AIZRULSHAH BIN KAMARUDDIN
B050910203
790407-01-6397
FACULTY OF MANUFACTURING ENGINEERING
2013
DECLARATION
I hereby, declared this report entitled Design and Optimization of Runner and
Gating for Permanent Casting is the results of my own research except as cited in
the references.
Signature
:
………………………………………….
Author’s Name
:
MOHAMMAD AIZRULSHAH BIN
KAMARUDDIN
Date
:
3.6.2013
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 committee is as follows:
----------------------------------------------------
ABSTRAK
Aliran bendalir memainkan peranan penting dalam menghasilkan acuan tuangan
yang berkualiti tinggi . Aliran bendalir
dipengaruhi oleh halaju tuangan
dan
pelari(runner) dan reka bentuk pintu (gating) acuan. Ia akan menentukan sama ada
aliran adalah gelora atau lamina. Proses reka bentuk adalah peringkat yang paling
penting dalam mana-mana pengeluaran produk yang sama seperti membuat acuan
kekal . Amalan semasa adalah kaedah cuba jaya untuk mendapatkan reka bentuk
acuan kekal yang terbaik. Dengan menggunakan perisian analisis cecair dinamik,
proses mereka bentuk pelari(runner) dan pintu (gating) boleh dipermudahkan.
Matlamat utama kajian ini adalah untuk mereka bentuk dan mengoptimumkan
pelari(runner) dan pintu (gating) untuk acuan tuangan kekal. Kaedah yang
digunakan dalam kajian ini adalah Solidworks 3D model dan ANSYS FLUENT
perisian pengiraan analisis bendalir dinamik. Model aliran gelora telah digunakan
untuk mensimulasikan aliran aluminium lebur LM6. Empat rekabentuk konsep telah
dianalisa oleh ANSYS FLUENT daripada segi tekanan statik, magnitud halaju,
tenaga kinetik bergelora, tenaga dalaman dan nombor sel Reynolds. Keputusan yang
diperolehi daripada simulasi dioptimumkan untuk mewujudkan acuan yang
sempurna. Kesimpulannya acuan kekal bagi proses acuan tuangan gravity telah
direka dan dioptimumkan dan ia telah memenuhi objektif projek. Analisis simulasi
adalah alat yang sangat berguna bagi jurutera yang boleh digunakan sebagai rujukan
untuk meningkatkan produktiviti dan kualiti produk, sistem atau proses.
i
ABSTRACT
Fluid flow plays a major role in producing good quality casting. The fluid flow is
influenced by the pouring velocity and the runners and gating design of the mold.
The design process is the most important stages in any product manufacturing same
as permanent mold making. The current practice is the experimenting method to
predict the best design. By using computational fluid dynamic analysis the process
of designing runners and gating can be improved. The main objective of this paper is
to design and optimize the runner and gating systems for permanent mold casting.
The method use in this paper is Solidworks 3D modeling and ANSYS FLUENT
computational fluid dynamic analysis software. Transient, turbulence flow model
has been applied to simulate the flow of molten aluminum LM6. The ANSYS
FLUENT analyzed 4 runners and gating design concept from the aspect static
pressure, velocity magnitude, turbulent kinetic energy, internal energy and cell
Reynolds numbers. The results gained from the simulation are optimized to create a
perfect mold. As a conclusion a permanent mold casting was designed and
optimized and it fulfilled the objective of the project. The simulation analysis is a
very powerful tool for engineers that can be used as a reference to improve
productivity and quality of product, system or process.
ii
DEDICATION
To beloved wife
Azlinda Mohamad
To my kids
Muhammad Izzu Syahmi and Maryam Kayyisah
And to my parents
Hj Kamaruddin Hj bin Hj Idris
Hjh Aisah binti Abu Bakar
iii
ACKNOWLEDGEMENT
I would like to thank my supervisor Dr Taufik for the support, guidance and
understanding during the making of this report. Thank to my wife Azlinda for the
patience and understanding. Thank also to my colleague for the idea, discussion and
encouragement.
iv
TABLE OF CONTENT
Abstrak
i
Abstract
ii
Dedication
iii
Acknowledgement
iv
Table of Content
v
List of Tables
viii
List of Figures
ix
CHAPTER 1: INTRODUCTION
1.1
Project Background
1
1.2
Problem Statement
3
1.3
Objective
3
1.4
Scope
3
1.5
Report Structure
4
CHAPTER 2: LITERATURE REVIEW
2.1
Casting And Its History
5
2.2
Permanent Mold Casting
8
2.2.1
9
Advantages Of Permanent Mold Casting
2.3.1.1.
Volume
9
2.3.1.2.
Tolerance and Surface finish
9
2.3.1.3.
Cost
10
2.2.2
Limitation Of Permanent Mold Casting
10
2.2.3
Defect In Permanent Mold
11
2.2.4
Permanent Mold Casting Process
13
2.3 Design
13
2.3.1 Rigging System Design
15
2.3.2 Riser Design
16
2.3.3 Feeding System In Riser Design
18
2.3.4 Gating
18
v
2.3.4.1 Gating Design Variables
19
2.3.4.2 Principle of fluid flow
20
2.3.4.3 Ideal gating design
22
2.3.5
Sprue Design
24
2.3.6 Runner Design
25
2.4
Pattern
26
2.5
Computer Aided Engineering
27
CHAPTER 3: METHODOLOGY
3.1
Project Planning
29
3.2
Overall Project Framework
29
3.2.1 Planning Stage
3.2.1.1.
Problem statement, objective and
scope of research identification
3.2.1.2.
31
Production tooling and
computational fluid dynamics
3.2.1.3.
31
31
Parameter permanent mold
design study
32
3.3.
Stage 2: The Design Stage
32
3.4.
Stage 3: Analysis And Result
34
3.5.
Stage 4: Report Preparation and Presentation
34
3.6.
The Design Concept Sketches
35
3.7.
Conclusion
36
CHAPTER 4: RESULT & DISCUSSION
4.1
The Design concept
37
4.1.1 Design concept 1
38
4.1.2 Design Concept 2
39
4.1.3 Design concept 3
39
Design concept 4
39
4.1.4
4.2
Ansys 14 Fluent Simulation
40
4.2.1 Ansys Fluent models
40
4.2.2 Ansys Fluent Material
40
4.2.2.1 Casting Material
40
vi
4.2.2.2 Wall Material
41
4.2.2.3 Cell Zone Condition
41
4.2.2.4 Boundary Condition
41
4.2.3 Ansys Simulation Result Data
43
4.2.3.1 Design Concept 1
43
4.2.3.2 Design Concept 2
47
4.2.3.3 Design Concept 3
52
4.2.3.4 Design Concept 4
57
4.3
Ranking
61
4.4
Optimization
63
4.4.1 The Runner And Gating Concept Design
63
4.4.2 Ansys Simulation Result Analysis
65
4.4.3 Ansys Fluent Flow Analysis Optimized
66
4.5
SolidWorks Modelling
70
4.6
Summary of Result
72
CHAPTER 5: CONCLUSION & FUTURE WORKS
5.1.
Conclusion
73
5.2.
Future works
74
REFERENCES
75
APPENDIX A
vii
LIST OF TABLES
4.1
LM6 Properties
41
4.2
Steel properties
41
4.3
The inlet Condition value
42
4.4
The outlet condition
42
4.5
Simulated Ansys Fluent data
43
4.6
Simulated Data
50
4.7
Simulated Data
55
4.8
Simulated Data
59
4.9a
Design 1 and 2 simulated data
61
4.9b
Design 3 and 4 simulated data
61
4.10
Maximum Value comparison
62
4.11
Ranking
62
4.12a Ansys Fluent Result for runner and gating optimize concept
66
4.12b Ansys Fluent Result for runner and gating optimize concept
66
4.13
70
Table of maximum value
viii
LIST OF FIGURES
1.1
Gooseneck Clamp
4
2.1
The important development in casting process
6
2.2
Expendable Mold process tree
7
2.3
Process tree under permanent mold casting. Yellow indicates the
8
scope of study
2.4
Approximate values of surface roughness and tolerance on
9
dimensions typically obtained with different manufacturing
processes. ECM, electro-chemical machining; EDM, electrical
discharge machining
2.5
Differences between manufacturing process
10
2.6a
Example defect in the casting process
12
2.6b
Example of common defects hot tear in casting. Which the
12
defect can be minimized or eliminate with proper design and
preparation of molds
2.7
Directional and progressive solidification in a casting equipped
17
with a riser
2.8
Basic component of a single gating system for a horizontal
19
parted mold
2.9
Schematic illustrating the application of Bernoulli’s theorem to a
22
gating system
2.10
Poor top gates and side-fed running system, compared with (b) a
23
more satisfactory bottom-gated and top-fed system.
ix
2.11
(c) Poor system gated at joint and (d) recommended economical
23
and effective system
2.12
Comparison of flow patterns in two vertical gating systems. (a)
24
Poorly designed system. (b) Properly designed system using a
tapered runner that equalizes flow through the ingates
2.13
Schematic showing the advantages of a tapered sprue over a
25
straight-sided sprue. (a) Natural flow of afree-falling liquid. (b)
Air aspiration induced by liquid flow in a straight -sided sprue. (c)
Liquid flow in a tapered sprue
2.14
Schematic illustrating fluid flow around right-angle and curved
26
bends in a gating system. (a) Turbulence resulting from a sharp
corner. (b) Metal damage resulting from a sharp corner. (c)
Streamlined corner that minimizes turbulence and metal damage
2.15
Goose neck clamp
2.16
Technical drawing and dimension of the gooseneck clamp
27
3.1
Project Framework Flow Chart
30
3.2
SolidWorks 3d modelling flow chart
33
3.3
Mold Design outline with SolidWorks
33
3.4
ANSYS 14 Fluent procedures flowchart
34
3.5
Sketch 1
35
3.6
Sketch 2
36
3.7
Sketch 3
36
3.8
Sketch 4
36
x
4.1
Design Concept 1
37
4.2
Design Concept 2
38
4.3
Design Concept 3
39
4.4
Design Concept 4
39
4.5
Contour of static pressure
43
4.6
Contour of velocity magnitude
44
4.7
Contour of turbulence kinetic energy
45
4.8
Contour of internal energy
45
4.9
Flow simulated
46
4.10
Temperature vs Time Chart
47
4.11
Contour of static pressure
48
4.12
Contour of velocity magnitude
49
4.13
Contour of turbulence kinetic energy
49
4.14
Contour of internal energy
50
4.15
Flow simulated
51
4.16
Temperature vs Time Chart
52
4.17
Contour of static pressure
53
4.18
Contour of velocity magnitude
53
4.19
Contour of turbulence kinetic energy
54
4.20
Contour of internal energy
55
4.21
Velocity Streamline Flow
56
4.22
Temperature vs Time Chart
56
xi
4.23
Contour of static pressure
57
4.24
Contour of velocity magnitude
58
4.25
Contour of turbulence kinetic energy
58
4.26
Contour of internal energy
59
4.27
Streamline Flow
60
4.28
Temperature vs Time Chart
61
4.29
Gating and runner optimized design 1
63
4.30
Gating and runner optimized design 2
64
4.31
Gating and runner optimized design 3
65
4.32
Ansys Fluent Streamline for optimized
66
4.33
Temperature vs Time Chart
67
4.34
Streamline Flow for concept 2 optimized
67
4.35
Temperature vs Time Chart
68
4.36
Streamline Flow for concept 3 optimized
68
4.37
Temperature vs Time Chart concept 3 optimized
69
4.38
Mold in close position
71
4.39
Mold Exploded view
71
4.40
Mold halves features
72
xii
CHAPTER 1
INTRODUCTION
This chapter discusses briefly the design and optimization of runner and gating
system for the permanent mold. This chapter of the report briefly discusses the
project background, problem statement, objective and scope.
1.1
Project Background
Casting is an economical and oldest manufacturing process in producing or
reproducing complex part in mass numbers. The first metal casting was found to be
made during the period from 4000 to 3000 BC using stone and metal to cast copper
and bronze (Kalpakjian and Schmid, 2006). Casting is a process in which molten
metal is poured into a cavity of a mold which are split or broken apart to extract the
solidified metal cast(Boothroyd et al. 2002). Designing a mold used in casting is
considered as an art and science. There is no exact formula or parameter can be
used. It depends on the mold designer experiences, trial and error. Casting is divided
into 2 categories which is non permanent and permanent molds. This report covers
the designing and the optimization of runner and gating system for permanent mold
casting.
Permanent mold casting is a method used to cast product or part using permanent
mold or non expendable mold unlike sand casting where the use of expendable mold
and the flows only at the force of gravity (Butler 1998). As the name implies non
1
expendable mold means that the mold is usually made from metal. The same
guidelines and rules use in designing a sand casting are applied in designing the
permanent mold. Except that in sand casting if there is an error or modification in
the design the mold can be crushed and reconstructed, this method did not apply to
permanent mold where it will require metal cutting and reshaping (Shamasundar et
al., 2010.). This will require cost therefore permanent mold need to be designed
carefully. Due to the material used for making the mold, it usually being used to cast
non ferrous alloy and some limited application for casting cast iron. Typical material
can be cast using permanent mold is aluminum, zinc, brass, copper, lead and even
gray cast iron. The benefit of using permanent mold casting is that the high
production runs due to faster cooling rate than sand. Permanent mold casting also
produces a product with high dimensional accuracy, near net shape and use less raw
material. Reasonable price cost can be achieved from the high production rate with
metal molds especially the water cooled molds compare to sand or investment
casting (Butler, 1998). Limitation of permanent mold casting is that not all shapes
can be cast using it, but with the combination of detachable and expendable core the
potential is limitless.
Defect effecting sand casting also applies to permanent mold casting such as
porosity and shrinkage.
In order to eliminate the defect, the mold to be designed
carefully. Design is the critical step in the development of cost effective, high
quality casting. In designing a good permanent mold the part geometry plays a big
role in effecting the load carrying functionality of the casting but also the mold
construction
(Stoll, 2009). The main purpose of designing the molds is to
concentrate liquid solid contraction until to the last portion of the casting to solidify
(Lampman,
2009). In the production of permanent mold the design or the
development stage use a lot of resources but quickly offset by the high production
run. A Goose neck machine clamps used for this study. Then the molds are design
using CAD software, the designed mold were tested using an analysis software.
Later the design will go optimization process. This project presents the design of
permanent mold use for casting a production tooling. The study on making a
permanent mold will give a lot in sight in the best method in the manufacturing of
the mold either using experimental or Computer Aided Engineering Software.
2
1.2
Problem Statement
Designing permanent molds for casting can be considered as
art and science.
Runners and the gating system are the most important part of the mold. There a
numerous guideline can be used for designing a mold but the position and size of the
runner and gating depended on the part want to cast. At the moment the current
practice in mold construction is an experimenting method where base on trial and
error. The trial and error method solely depended on the design engineers
knowledge and experience. However this practice is time consuming and high cost.
In this report the product use for study is a Goose neck machine clamp. Finding the
position and size of the runner and gating system is crucial to produce defect free
product and near net shape as possible. This project presents the design of
permanent molds, design and analyze using Computer Aided Engineering software.
1.3
Objective
1.3.1 To investigate the design parameter of a permanent mold casting for Goose
neck machine clamp.
1.3.2 To analyze and optimize the permanent mold casting Computer Aided
Engineering software.
1.3.3 To design a permanent mold casting for Goose neck machine clamp.
1.4
Scope
This report only focuses on mold design of a production tooling called Goose neck
machine clamp. The report also considers the existing optimum parameters for
casting molds. The mold geometry design using SolidWorks design software and
analyze using the ANSYS FLUENT software. The mold designed is for gravity
feed casting. Aluminum LM6 and stainless steel is use as the molten metal and mold
in the analysis.
3
Figure 1.1 Goose neck clamp
1.5
Report Structure
Chapter 1 describes the background of the study. Chapter 2 consists of the literature
review and chapter 3 the methodology of the research project. Chapter 4 explained
the result finding and chapter 5 the conclusion.
CHAPTER 2
LITERATURE REVIEW
This chapter consists of the information gathered regarding the project title which is
Design and optimization of runner and gating system for permanent mold casting.
The information collected from books and previous study. Tools and software used
in this project also will be explained in this report.
2.1 Casting And Its History
Casting can be considered as an oldest manufacturing method know to man. It's a
method used to produce parts in mass numbers. Casting was first used around 4000
B.C to cast ornament and copper arrow head (Kalpakjian and Schmid, 2006).
Copper is the first metal to be cast and usually the component made were weapon
arrow head or axes. During the Bronze Age (3000-1500 BC) alloys such as tin
bronze and arsenical copper were developed. Alloying, as well as reducing the
melting temperatures required, improved the strength of the finished product and
helped to oxidize the melt, enabling a better surface finish and higher level of detail
to be obtained because of the enhanced fluidity (Jolly 2003).
There some archeological find and the oldest casting in existence is a copper frog
dated 3200 BC discovered in Mesopotamia. One of the first cast iron objects, a 270
kg tripod, was cast by Chinese in 600 BC. A colossal statue of the Great Buddha in
tin lead bronze was completed in 1252 AD at Kamakura in Japan (Ratnakar, 2004).
5
There is also some archaeological evidence that the “lost
ost w
wax” process was
developed at about
bout the beginning of the Bronze Age. This method
hod was used to cast
small object mainly
nly jewelry (Jolly 2003). Later on this method
hod was renamed the
investment casting.. T
The figure 2.1 below show the important deve
velopment in casting
process.
Figure 2.1 The important development in casting process (Jolly
lly 2003).
6
Casting can be used to produce a wide variety of product with complex shape and it
only involves one major manufacturing method. Casting involves pouring molten
metal in a mold cavity that configured to the shape and dimension of the intended
finish product. Casting can be divided into 2 major categories which is expandable
and non expandable mold. Figure 2.2 below illustrates the process tree under the
expandable mold process
Expendable
mold
with permanent
patterns
Lost foam
Investment
casting
Replicast
process
Counter
gravity
with expandable
patterns
Bonded
sand
molding
Green Sand
CO2
Slurry
molding
Plaster
Rammed
graphite
molding
Ceramics
Nonbonded
sand molding
Vacuum
molding
Magnetic
molding
Resin
Bonded
Figure 2.2 Expendable Mold process tree
As the name implies the expendable mold process use material that are expendable
such as sand or other granular mold material. In expendable mold casting with
permanent pattern the mold needed be split into in order to remove the pattern
before the actual pouring process is done. Due to the title of the project the
expendable mold will not be explained further.
7
2.2 Permanent Mold Casting
Permanent mold casting is a casting process that uses non expendable that are either
made from metal or graphite. Permanent mold processes involve the production of
castings by pouring molten metal into permanent metal molds using gravity, low
pressure, vacuum or centrifugal pressure and simple reusable cores are usually
made of metal (Lampman, 2009). The mold cavity and the gating system are
machined into the mold and become an integral part of the mold (Kalpakjian and
Steven, 2006). That's why the design of the mold is crucial. Figure 2.3 illustrated the
process tree under permanent mold casting process.
Permanent mold
permanent and
semi permanent
mold
Gravity permanent
mold
High pressure die
casting
low pressure
permanent mold
Conventional high
pressure die
casting
Static pour
permanent mold
Convetional Low
pressure
Squeeze Casting
Tilt mold
permanent mold
Vacuum/pressure
riserless
Semisolid
processing
Pressure/ couter
pressure
Vacuum Die
casting
Figure 2.3 Process tree under permanent mold casting. Yellow indicates the scope of study.
8