Upload
phamthuan
View
215
Download
0
Embed Size (px)
Citation preview
UNIVERSITI TEKNIKAL MALAYSIA MELAKA
Study Performance of Cylindrical Grinding
on Surface Roughness
Thesis submitted in accordance with the requirements of the Universiti
Teknikal Malaysia Melaka for the Bachelor of Manufacturing Engineering
(Manufacturing Process)
By
Ahmad Anwar Bin Hamdan
(B050510078)
Faculty of Manufacturing Engineering
May 2008
UTeM Library (Pind.1/2007)
UNIVERSITI TEKNIKAL MALAYSIA MELAKA
BORANG PENGESAHAN STATUS LAPORAN PSM
JUDUL:
Study Performance of Cylindrical Grinding on Surface Roughness
SESI PENGAJIAN:
Semester 2 2007/2008
Saya Ahmad Anwar Bin Hamdan
mengaku membenarkan laporan PSM / tesis (Sarjana/Doktor Falsafah) ini disimpan di Perpustakaan Universiti Teknikal Malaysia Melaka (UTeM) dengan syarat-syarat kegunaan seperti berikut:
1. Laporan PSM / tesis 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 / tesis ini sebagai bahan pertukaran antara institusi pengajian tinggi.
4. *Sila tandakan (√)
SULIT
TERHAD
TIDAK TERHAD
(Mengandungi maklumat yang berdarjah keselamatan atau kepentingan Malaysia yang termaktub di dalam AKTA RAHSIA
RASMI 1972)
(Mengandungi maklumat TERHAD yang telah ditentukan oleh
organisasi/badan di mana penyelidikan dijalankan)
(TANDATANGAN PENULIS) Alamat Tetap: Batu 8, Kg Paya Luas Batu Anam 85100 Segamat Johor Darul Takzim
Tarikh: 20 MAY 2008
(TANDATANGAN PENYELIA)
Cop Rasmi:
Tarikh: _______________________
* Jika laporan PSM ini SULIT atau TERHAD, sila lampirkan surat daripada pihak organisasi berkenaan
dengan menyatakan sekali sebab dan tempoh tesis ini perlu dikelaskan sebagai SULIT atau TERHAD.
DECLARATION
I hereby declare that this report entitled “Study Performance of Cylindrical Grinding
on Surface Roughness” is the result of my own research except as cited in the
references.
Signature :
Author’s Name : Ahmad Anwar Bin Hamdan
Date : 20 May 2008
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 Process). The members of the supervisory committee
are as follow:
…………………….
(PSM Supervisor)
Mr. Mohamad Amri Bin Sulaiman
(Official Stamp & Date)
i
ABSTRACT
This research presents the effects of cylindrical grinding parameters (spindle speed,
traverse speed, and depth of cut; infeed) on the surface roughness for PS A 80 K 8 V
6N grinding wheel tools, in grind AISI 1040 medium carbon steel. The process of
grinding was done by Universal Cylindrical Grinder SHARP OD618 S/H with
traverse grinding operation selected. The intervals of parameters were decided after
referred from suitable recommendation provided. The surface roughness value will
obtained by using Mitutoyo’s SJ-301 surface roughness tester. The result will
compare with experiment hypothesis to measure the affect of variable parameter to
surface roughness changes. Interpretation of result will used for further reference for
checking suitable condition parameter on various conditions of operations.
ii
ABSTRAK
Penyelidikan ini merangkumi kesan parameter (spindle speed, traverse speed dan
depth of cut) daripada operasi cylindrical grinding terhadap kekasaran permukaan
dengan penggunaan pengisar batu canai PS A 80 K 8 V 6N pada bahan keluli karbon
sederhana AISI 1040. Proses mengisar telah dilakukan oleh Universal Cylindrical
Grinder SHARP OD618 S / H dengan kelajuan operasi mengisar yang telah
ditetapkan. Selang bagi setiap parameter ditetapkan dengan merujuk aturan dan
cadangan kelajuan bagi setiap parameter. Kemudian, nilai kekasaran permukaan akan
memperolehi dengan menggunakan Mitutoyo's SJ-301; penguji kekasaran
permukaan. Hasilnya akan bandingkan dengan hipotesis eksperimen mengukur kesan
parameter serta pembolehubah untuk setiap perubahan kekasaran permukaan.
Keputusan yang dicapai adalah berguna sebagai rujukan dalam memilih kesesuaian
parameter di dalam pelbagai operation pencanaian.
iii
DEDICATION
For my beloved parent, my family best friend and all friends, and to those who’s with
me all this time
iv
ACKNOWLEDGEMENTS
Alhamdulillah, thank to Allah the Almighty God for giving me strength and
patience to work on this Final Year Project Report.
I would like to take this opportunity to express my sincere and deepest
gratitude to my Project Supervisor; Mr. Mohamad Amri Bin Sulaiman, for his
guidance and opinion in the cause of completing this report.
My greatest thanks to my beloved family for their prayers, support, and
encouragement to me for throughout this entire period of these Final Year Project 1
and 2. I would like to thanks Professor Dr. Mohd. Razali Bin Muhamad; Dean of
Faculty of Manufacturing Engineering, University Technical Malaysia, Melaka, Mr.
Mohd Hadzley Bin Abu Bakar; Academic Supervisor, and to all the lectures in the
faculty.
I also would like to convey my biggest thanks to all FKP technicians for
supporting me throughout my project. The knowledge and experience I gained from
you all will not be forgotten.
I’m also obliged to everyone who had directly and indirectly involve through
contributions of ideas, as well as materials and professional opinions.
Last but not least, to Yeoh Phooi San and. all my friends out there for their
moral support and valuable help that they have provided me throughout my project.
v
TABLE OF CONTENTS
Abstract i
Dedication iii
Acknowledgements iv
Table of Contents v
List of Figures ix
List of Tables xii
List of Abbreviations, Symbols, Specialized Nomenclature xiii
List of Appendices xiv
1. INTRODUCTION
1.1 Background of Project 1
1.2 Objective 2
1.3 Scope of Project 2
2. LITERATURE REVIEW
2.1 Introduction 4
2.2 Review: Grinding Due to Surface Finish 5
2.2.1 Reasons for Grinding 7
2.2.2 Machining removes excessive material 8
2.3 Review: Cylindrical Grinding 9
2.3.1 Introduction 9
2.3.2 Cylindrical Grinding Machine 9
2.3.3 Concept in Cylindrical Grinding 10
2.3.4 Method in Cylindrical Operation 14
2.3.5 Grinding Wheel 15
2.3.5.1 Wheel Properties 16
vi
2.3.5.2 Abrasive Grain Properties 17
2.3.5.3 Standard Marking System Chart 18
2.4 Parameter in Grinding 20
2.5 Review: Surface Integrity 21
2.5.1 Introduction 21
2.5.2 Review: Surface Roughness 22
2.5.2.1 Description of Surface Roughness 24
2.5.3 Surface Roughness Measurement 26
2.5.3.1 Direct Measurement Methods 27
2.5.3.2 Comparison Based Techniques 27
2.5.3.3 Non Contact Methods 27
2.5.3.4 On-process measurement 28
2.6 Review: Profilometer 29
2.6.1 Advantages of contact profilometers 30
3. METHODOLOGY
3.1 Studies of Cylindrical Grinding Operation and Process 32
3.1.1 Traverse Grinding Operations 34
3.1.2 Grinding Wheel Specification 34
3.1.3 Wheel Marking 35
3.2 Research of Parameter in Cylindrical Grinding Process 35
3.2.1 Wheel Speed 35
3.2.2 Traverse Speed 37
3.2.3 Depth of Cut 39
3.2.4 Parameter Selected for Further Studies 39
3.3 Training with Universal Cylindrical Grinder 41
3.4 Planning for Material Preparation 44
3.5 Perform Grinding Operation on Parameters Selected 45
3.5.1 Starting up Machine 46
3.5.2 Truing and Dressing a Grinding Wheel 48
vii
3.5.2.1 Truing 48
3.5.2.2 Dressing 49
3.5.2.3 Truing and Dressing a Grinding Wheel 49
3.5.3 Performing Grinding on the Workpiece 52
3.6 Study and Applying Measurement Method for Surface Roughness 59
3.7 Recording, Collecting and Analyzing Data Measurement and Data
of Surface Roughness 62
4. RESULT
4.1 Introduction 63
4.2 Area of Contact 63
4.3 Effect of Grinding Due To Surface Roughness 64
5. DISCUSSION
5.1 Introduction 71
5.2 Influences in Grinding Operation 71
5.3 Influences in Method of Measurements 72
5.4 The Surface Finish Factors by Spindle Speed 72
5.5 The Surface Roughness Factors by Traverse Speed 74
5.6 The Surface Roughness Factor by Grinding Wheel Infeed (depth of cut) 76
5.7 Factor of Traverse Length of Wheel to Sample 77
5.8 Relations between Parameters 79
5.9 Factor from Process in Grinding Operation 84
5.9.1 Un-uniformity Dressing 84
5.9.2 Spark 85
5.9.3 Grinding Fluid 86
6. CONCLUSION
6.1 Conclusion 88
6.2 Recommendation 89
viii
REFERENCES 91
APPENDICES
A Wheel Marking & Shape of Wheel
B Machine Specifications
C Description of Machine
D Machine Features
E Cutting Parameter
F Material Properties AISI 1040
G Standards Sj-301 Configuration
H Switching the Profile Filter
I Evaluation According To JIS B0601-2001 and ISO
J Table and Result of Measurement
K ISO 4288, 1996: Surface Roughness Texture: Profile Method – Rules and
Procedures for the Assessment of Surface Texture
L The Indication of Surface Lay According To ISO 1302, 2001
M Roughness from Process Factor
ix
LIST OF FIGURES
Figure 2.1 The Input, Constraints, Outputs and Mechanism considered
when analyzing and modelling a grinding process (Warren
Richard, 1992).
8
Figure 2.2 Example of various cylindrical operation including traverse
grinding, plunge grinding, and profile’s grinding (Kalpakjian S,
2001).
11
Figure 2.3 External and internal grinding for traverse and plunge process.
(Prof. Dr.-Ing. F. Klocke, 2007).
12
Figure 2.4 Various grinding operation for cylindrical part (Geoffrey
Boothroyd, 1989).
13
Figure 2.5 Traverse grinding operation with different traverse speed
(Franklin D. Jones, 1964).
14
Figure 2.6 Condition for external grinding (Black S C, 1998). 15
Figure 2.7 Types of abrasive grain in wheels. 16
Figure 2.8 Composition of an abrasive wheel (S C Black 1998). 17
Figure 2.9 Friability of wheel during grinding operation (Warren Richard,
1992).
17
Figure 2.10 Hardness comparison between abrasive grain (Warren Richard,
1992).
18
Figure 2.11 Industry Standard of wheel specifications (Pacific Grinding
Wheel Company).
18
Figure 2.12 Parameters have to control during grinding operation (Franklin
D. Jones, 1964).
21
Figure 2.13 Profile in surface appeared on the workpiece (S C Black, 1998). 23
Figure 2.14 Checking profile on surface using stylus method
(http://en.wikipedia.org/wiki/Profilometer).
25
Figure 2.15 Determination of Ra (m is the mean line) (A. W. Batchelor, 26
x
2002).
Figure 2.16 Electronic speckle correlation using lens (A. W. Batchelor,
2002).
28
Figure 2.17 Schematic figure checking roughness using stylus method
(http://en.wikipedia.org/wiki/Profilometer).
31
Figure 3.1 Universal Cylindrical Grinder (refer Appendix C). 34
Figure 3.2 Universal cylindrical grinder for external, internal and taper
grinding process.
42
Figure 3.3 Chuck for ground the cylindrical workpiece. 42
Figure 3.4 Wheel for external grinding process. 43
Figure 3.5 Wheel to control depth of cut and table traverse. 4.3
Figure 3.6 Control and switch panel. 44
Figure 3.7 Internal grinding process through bore in workpiece. 44
Figure 3.8 Raw material before processing to be sample. 45
Figure 3.9 Switch for power on. 46
Figure 3.10 The buttons pushed simultaneously. 47
Figure 3.11 Main switch at the machine has to switch on. 47
Figure 3.12 Power button on the control panel has to push ON. 48
Figure 3.13 End stock which attach with diamond dresser. 50
Figure 3.14 The diamond dresser move ahead close to the wheel. 50
Figure 3.15 Auto-traverse dressing. 51
Figure 3.16 Infeed for dressing the wheel with suggested amount. 52
Figure 3.17 Place the workpiece into the chuck. 53
Figure 3.18 Fasten the workpiece on chuck properly. 53
Figure 3.19 Coolant is flushing on the grinding wheel. 54
Figure 3.20 Slowly infeed the samples to the wheel. 55
Figure 3.21 Set up the correct spindle speed as parameter required. 55
Figure 3.22 Set up correct traverse speed as parameter required. 56
Figure 3.23 Set position of reversing dog for table traverse. 56
xi
Figure 3.33 Knob for locking the table for auto-traverse cycle. 57
Figure 3.34 Set the infeed to zero align. 57
Figure 3.35 Cycling the operation until meet the parameter. 58
Figure 3.36 Normal position should be set after machining done. 58
Figure 4.1 Point for taken measurement. 64
Figure 4.2 Interrelation of spindle speed effect to surface roughness. 66
Figure 4.3 Interrelation of traverse speed effect to surface roughness. 68
Figure 4.4 Interrelation of depth of cut (infeed) effect to surface roughness. 70
Figure 5.1 Slope of effect by spindle speed to surface roughness. 73
Figure 5.2 Small spark produced in 10.72 rpm of spindle speed. 74
Figure 5.3 Slope of effect by traverse speed to surface roughness. 75
Figure 5.4 Crossed lay produces in high traverse speed. 75
Figure 5.5 Slope of effect by depth of cut (infeed) to surface roughness. 77
Figure 5.6 Length of grounded and grinding area on sample. 78
Figure 5.7 Influencing of parameters to result the surface roughness. 79
Figure 5.8 Interrelation of spindle speed and traverse speed. 81
Figure 5.9 Interrelation of spindle speed and depth of cut (infeed). 82
Figure 5.10 Interrelation of traverse speed and depth of cut (infeed). 83
Figure 5.11 Roughness of wheel effect by dressing lead (David J.
Whitehouse).
85
Figure 5.12 Insufficient grinding fluid and viscous. 86
Figure 5.13 Grinding fluid mixed with metal dust. 87
xii
LIST OF TABLES
Table 3.1 Recommend wheel speed (Roger Timing, 2002). 36
Table 3.2 Workpiece periphery speed range (Asian Autotec, 2007). 37
Table 3.2 Feed rate per grinding (Asian Autotec, 2007). 38
Table 3.4 Relation between variable and fix parameters. 39
Table 3.5 Range of spindle speed with fix other parameters. 40
Table 3.6 Range of traverse speed with fix other parameters. 40
Table 3.7 Range of depth of cut with fix other parameters. 41
Table 4.1 Data Recorded of surface roughness measurement in spindle
speed parameter.
65
Table 4.2 Data recorded of surface roughness measurement in traverse
speed parameter.
67
Table 4.3 Data recorded of surface roughness measurement in depth of
cut (infeed) parameter.
69
Table 5.1 Clashing points of Ra between spindle speed and traverse
speed.
80
Table 5.2 Clashing points of Ra between spindle speed and depth of cut
(infeed).
82
Table 5.3 Clashing point of Ra between traverse speed and depth of cut
(infeed).
83
xiii
LIST OF ABBREVIATIONS, SYMBOLS, SPECIALIZED
NOMENCLATURE
HV Hardness Vickers
SEM Scanning Electron Microscope
Sk Skewness Of The Profile
AISI 1040 Medium Carbon Steel Graded By American Iron And Steel
Institute
Ra Arithmetic Mean Deviation Of The Profile
Rmax Maximum Peak To Valley Height Of The Profile
Rp Maximum Profile Height
Ry Maximum Height Of The Profile
μm Micrometer (Micron)
CCD Charge-Coupled Device
CLA Center Line Average
PS A 80K V 6N
Wheel Grade: [PS; Manufactures Abrasive Code][A; Aluminum
Oxide][80; Grain Size, Fine][K; Grade, Medium][V; Porosity][V;
Bond Type, Vitrified][6N; Manufactures Bond Code]
xiv
LIST OF APPENDICES
A Wheel Marking & Shape of Wheel
B Machine Specifications
C Description of Machine
D Machine Features
E Cutting Parameter
F Material Properties AISI 1040
G Standards Sj-301 Configuration
H Switching the Profile Filter
I Evaluation According To JIS B0601-2001 and ISO
J Table and Result of Measurement
K ISO 4288, 1996: Surface Roughness Texture: Profile Method – Rules and
Procedures for the Assessment of Surface Texture
L The Indication of Surface Lay According To ISO 1302, 2001
M Roughness from Process Factor
1
CHAPTER 1
INTRODUCTION
1.1 Background of Project
Cutting processes are among the most important of manufacturing operation.
They are often necessary in order to impart the desired surface finish and
dimensional accuracy to component, particularly those with complex shape that
cannot be produced economically or properly by other techniques.
A large number of variables have significant influence on the mechanics of
chip formation in cutting operations. Commonly observed chip types are continuous,
built-up edge, discontinuous and segmented. Among important process variables are
tool shape and material, cutting conditions such as speed, feed, and depth of cut, use
of cutting fluids, and the characteristics of the machine tool, workholding device,
fixturing, as well as the characteristics of the workpiece material, parameters
influenced by these variables are force and power consumption, tool wear, surface
finish and integrity, temperature, and dimensional accuracy of the workpiece.
Machinability of materials depends not only on their intrinsic properties, but also on
proper selection and control of process variables.
The distinction between a finishing operation and other processes that affect
the surface is that finishing processes are not intended significantly change the
dimension of a part (William O. Feller, 2001). Rather, this finishing operation is
intended to achieve closer tolerances and provide protective coating. It is also able to
improve the appearance of the part.
Surface finish is specified by giving the desired waviness, roughness, and lay
of the desired surface. Waviness refers to the long-range undulations in the surface,
not necessarily those left by the tool marks. Roughness refers to the finely spaced
2
textured irregularities. Roughness is usually determined by the tool marks of the final
operation.
The quality of machined surface is characterized by the accuracy of its
manufacture with respect to the dimensions specified by the designer. Every
machining operation leaves characteristic evidence on the machined surface. This
evidence in the form of finely spaced micro irregularities left by the cutting tool.
Each type of cutting tool leaves its own individual pattern which therefore can be
identified. This pattern is known as surface finish or surface roughness.
1.2 Objective
The objectives of this experiment are:
(a) To study the relationship between the surfaces roughness values and
cylindrical grinding parameters such as spindle speed, traverse speed
and also depth of cut. From the study, we were able to study
performance the cylindrical grinding due to its parameter to produces
better surface finish.
(b) To analyzed the surface roughness of the material of cylindrical
grinding operation such as the surface texture and surface profile.
1.3 Scope of Project
This project is about investigating the surface roughness on medium carbon
steel AISI 1040 during cylindrical grinding operation using PS A 80 K 8 V 6N wheel
as cutting tools. This process is done on the Universal Cylindrical Grinder OD-618
S/H in the room temperatures. During this machining several cutting parameters such
as feed rate, spindle speed and depth of cut are frequent varied in selected range with
1960 rpm of grinding wheel are fixed. 45 samples are used to complete all
parameters decided to further surface roughness analyzing.
3
Profilometer of Surface roughness Tester Mitutoyo SJ-301, of will be used to
measure and identify the surface roughness and it values. This will determine the
surface roughness of the material after completing the grinding operations. The
factors that influence the surface roughness is will be identified after the material
have been machined.
4
CHAPTER 2
LITERATURE REVIEW
2.1 Introduction
Machine tools and cutting tools have advanced in great developments in the
past few years. In the past few years ago, machining is a difficult task to be
performed but now this task has become common place and have been simplified
with more advanced technology that have been involved. Machining, the broad term
used to describe removal of material from a workpiece (Kalpakjian S, 2001).
Each process should be studied in order to understand the interrelationships
of design parameters, such as dimensional accuracy, surface finish and integrity, and
process parameters such as speed, feed, depth of cut, tool material and shape, and
cutting fluids.
A variety of abrasive processes and machinery are available for surface,
external, and internal grinding. The selection of abrasives and process variable in
these operations must be controlled in order to obtain the desired surface and
dimensional accuracy. Otherwise, damage to surfaces such as burning, heat
checking, and harmful residual stresses may develop. Several finishing operations
are available for debarring. Because contribute significantly to product cost, proper
selection and implementation of finishing operations are important.
In written of William O. Feller (Fellers W. O., 2001), the result to breaking
and cutting a piece of material depends on several factors:
(a) The properties of the material being cut.
(b) The properties of the cutting tool.
(c) The speed at which the material is cut.
5
Those factor giving then the result on the workpiece such as geometric shape,
dimension, appearance, and also surface integrity. Thus some parts that have been
producing in machining would to have other finishing operations, such as grinding.
This operation is important to obtain the desire final dimension and surface finish
(Kalpakjian S, 2001).
The principle differences between the cutting action of grinding and other
removal operation lie in the following (S C Black, 1998):
(a) Grinding grits are sufficiently hard to cut fully hardened steels of the
order of 850 HV.
(b) The cutting angles of the grits have random geometry.
(c) The pitch of the grit cutting edges is much smaller than the pitch other
cutter teeth.
(d) The size of the chips cut is very small for grinding.
2.2 Review: Grinding Due to Surface Finish
When study of a geometry and surface finish of metal removing, is necessary
in order to achieve efficiency of operations. When roughing, the aim is to remove a
particular volume of metal in minimum time, when finishing, the area finished
surface produced is the criterion, and where the area surface produced is the decisive
feature.
Since the metal removal rate w = df x Vc mm3/s, any increase in cutting
speed, depth of cut of feed will give a directly proportional increase in the metal
removal rate. The power available at the machine spindle is one factor limiting the
metal removal rate (Black S C, 1998).
Grinding and various abrasive-removal processes are capable of producing
the finest accuracy and surface finish in manufactured products. The majority of
abrasive processes are basically finishing operations that are usually performed on
machined or cold-worked parts. However, abrasives are also used for large-scale
6
material-removal processes, such as creep-feed grinding
(http://industrialtech.freeservers.com).
As with other conventional grinding processes, cylindrical grinding is a
manufacturing method using tools with lots of undefined geometrical cutting edges,
which are formed by a large number of abrasive grains made of natural or synthetic
abrasive material that remove the workpiece material at high speeds. In the case of
external cylindrical grinding, two cylindrical bodies generally come into contact with
each other. The length or surface of contact is relatively small (Tawakoli T. et al,
2006).
In the grinding process, because of the undefined geometrical cutting edges,
there is a large amount of heat caused by different mechanism of shear, friction and
separation, which is only partially dissipated by the chips and the rest can lead to a
considerable thermal strain and burning on the workpiece and also on the tools. The
reduction of heat build-up and proper cooling during grinding are therefore of
immense importance (Tawakoli T. et al, 2006).
The geometrical parameters like tolerances or roughness are generally
determined by the workpiece drawing and they are fixed. In order to achieve such
geometrical parameters and defined accuracy, grinding parameters like depth of cut
or traverse feed should be so selected in such a way that grinding forces do not
exceed from a critical amount which causes thermal damage. It means that they must
be relatively small. Unfortunately, these limited grinding forces decrease material
removal rate and increase production time (Tawakoli T. et al, 2006).
Chatter is critical to grinding processes because accuracy and surface finish
are the two major purposes for grinding processes. In addition, grinding processes
are inherently susceptible to chatter. When chatter boundaries are known, one can
design a grinding process without chatter. Thus, it is important to study chatter
mechanisms and predict grinding chatter boundaries and growth rates (Hongqi Li et
al, 2007).
Most recently, Li and Shin (Hongqi Li et al, 2007) presented a
comprehensive time-domain dynamic model, which simulates cylindrical plunge
grinding processes under general grinding conditions. The model focused on the
prediction of grinding chatter boundaries. Critical issues were considered in the