UNIVERSITI TEKNIKAL MALAYSIA MELAKA

EFFECT OF CHILLED AIR COOLANT ON SURFACE

ROUGHNESS AND TOOL WEAR WHEN MACHINING 2205

DUPLEX STAINLESS STEEL

This report submitted in accordance with requirement of the Universiti Teknikal

Malaysia Melaka (UTeM) for the Bachelor Degree of Manufacturing Engineering

(Manufacturing Process) (Hons.)

by

UMIRA SYAFIKA BINTI HASHIM

B051210032

910330-10-5052

FACULTY OF MANUFACTURING ENGINEERING

2016

UNIVERSITI TEKNIKAL MALAYSIA MELAKA

BORANG PENGESAHAN STATUS LAPORAN PROJEK SARJANA MUDA

TAJUK: Effect of Chilled Air Coolant on Surface Roughness and Tool Wear When

Machining 2205 Duplex Stainless Steel

SESI PENGAJIAN: 2015/16 Semester 2

Saya UMIRA SYAFIKA BINTI HASHIM

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.

4. **Sila tandakan (√)

SULIT

TERHAD

/ TIDAK TERHAD

(Mengandungi maklumat yang berdarjah keselamatan atau

kepentingan Malaysiasebagaimana yang termaktub dalam

AKTA RAHSIA RASMI 1972)

(Mengandungi maklumat TERHAD yang telah ditentukan oleh

organisasi/badan di mana penyelidikan dijalankan)

Alamat Tetap:

Lot 6065 Jalan Nazir,

Kampung Sg. Ramal Dalam,

43000, Kajang, Selangor.

Tarikh: 21 JUN 2016

Disahkan oleh:

Cop Rasmi:

Tarikh: 21 JUN 2016

** Jika Laporan PSM ini SULIT atau TERHAD, sila lampirkan surat daripada pihak berkuasa/organisasi

berkenaan dengan menyatakan sekali sebab dan tempoh laporan PSM ini perlu dikelaskan sebagai

SULIT atau TERHAD.

DECLARATION

I hereby, declared this report entitled “Effect of Chilled Air Coolant on Surface

Roughness and Tool Wear When Machining 2205 Duplex Stainless Steel” is the

results of my own research except as cited in references.

Signature :

Author’s Name : Umira Syafika Binti Hashim

Date : 21 JUN 2016

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) (Hons.). The member of

the supervisory is as follow:

………………………………

(Dr. Liew Pay Jun)

i

Cecair pemotong adalah penting untuk meningkatkan kemudahan sesuatu alatan

kerja untuk dimesin. Walau bagaimanapun, cecair pemotong konvensional adalah

tidak ekonomik dan berbahaya kepada alam sekitar dan kesihatan. Oleh itu, kaedah

penyejuk bukan konvensional dikaji untuk mengatasi masalah ini. Dalam kajian ini,

kesan penyejuk udara sejuk pada kekasaran permukaan dan kehausan alat apabila

pemesinan 2205 dupleks keluli tahan karat disiasat. Udara termampat disejukkan

dengan menggunakan tiub vorteks. Udara sejuk dan udara panas yang dihasilkan

melalui tiub vorteks daripada sumber udara termampat. Kajian ini juga melibatkan

perbandingan antara prestasi pemesinan antara penyejuk banjir konvensional dan

penyejuk udara sejuk. Ujian telah dijalankan pada mesin perubahan konvensional

dengan TiAlN bersalut alat karbida dan parameter yang berterusan terpilih adalah

kadar suapan, kedalaman pemotongan, dan kelajuan pemotongan. Kekasaran

permukaan dan kehausan alat diukur bagi setiap kali eksperimen dijalankan. Jangka

hayat mata alat dan kemasan permukaan bahan kerja telah dianalisis dalam setiap

keadaan pemotongan. Keputusan eksperimen menunjukkan bahawa penyejuk udara

sejuk memberikan kemasan permukaan yang lebih baik daripada penyejuk banjir

konvensional. Walau bagaimanapun, jangka hayat alat adalah lebih baik apabila

menggunakan penyejuk banjir konvensional berbanding penyejuk udara sejuk. Bagi

kedua-dua kaedah penyejuk, hasilnya menunjukkan penurunan corak untuk

kekasaran permukaan dan kehausan mata alat apabila suhu pendingin udara sejuk

menurun.

ABSTRAK

ii

Cutting fluid is important to enhance machinability. However, conventional cutting

fluid is uneconomical and hazardous to environment and health. Thus, non

conventional coolant method is studied in order to overcome these problems. In this

study, the effect of chilled air coolant on surface roughness and tool wear when

machining 2205 duplex stainless steel is investigated. The compressed air is chilled

by using vortex tube. Cold air and hot air is produced by means of vortex tube from

the source of compressed air. This study also investigated the comparison of

machining performance between conventional flood coolant and chilled air coolant.

The tests were conducted on a conventional turning machine with TiAlN coated

carbide tools and the constant parameters selected were feed rate, cutting depth, and

cutting speed. Surface roughness and tool wear were measured after each run and the

results were analysed. The experiment results showed that chilled air coolant gave

better surface finish compared to conventional flood coolant. However, tool life was

better when using conventional flood coolant compared to chilled air coolant. For

both coolant method, the result showed decreasing trend for surface roughness and

tool wear values when the temperature of chilled air coolant decreased.

ABSTRACT

iii

To my beloved family

DEDICATION

iv

I would like express my deep gratitude to Associate Professor Dr Md Nizam Bin

Abd Rahman for his valuable and constructive suggestion during the planning and

development of this research throughout Projek Sarjna Muda 1. Also, I would like to

express my great appreciation to Dr Liew Pay Jun, who has supported me throughout

Projek Sarjana Muda 2 with her guidance, motivation and knowledge.

Special thanks to Dr Shahir Kasim, Encik Fairuz Dimin, Dr Raja Izamshah Raja

Abdullah and Dr Mohd Hadzley Abu Bakar for their help, guidance and knowledge

which are very useful to me in doing my research.

I would also like to extend my thanks to engineer assistance for helping me handling

the laboratory equipments. And thank you for teaching me how to use the machine

and other equipments.

Lastly, I would like to thank my family and friends for their endless support

throughout completing this research.

DEDICATION

v

TABLE OF CONTENT

Abstrak i

Abstract ii

Dedication iii

Acknowledgement iv

Table of Content v

List of Tables vii

List of Figures ix

List of Equations xi

List of Abbreviations xii

CHAPTER 1: INTRODUCTION

1.1 Introduction 1

1.2 Problem Statement 3

1.3 Objectives 3

1.4 Scope 3

CHAPTER 2: LITERATURE REVIEW

2.1 Turning Process 5

2.2 Machining Parameters 6

2.2.1 Cutting Speed 6

2.2.3 Depth of Cut 7

2.2.4 Studies on Machining Parameter 7

vi

2.3 Workpiece Material 9

2.3.1 Stainless Steel 9

2.4 Cutting Tools 12

2.4.1 Coated Tungsten Carbide 13

2.5 Tool and Work Holding 13

2.5.1 Work Holding 13

2.5.2 Tool holding 14

2.6 Surface Roughness 14

2.7 Tool Wear 16

2.7.1 Flank Wear 16

2.8 Cutting Temperature 19

2.9 Cutting Fluid 20

2.9.1 Types of Cutting Fluid 20

2.9.2 Cooling Method in Machining 21

2.9.4 Studies on Cutting Fluid 25

CHAPTER 3: METHODOLOGY

3.1 Process Flow 31

3.2 Experimental Procedure 33

3.3 Experimental Matrix 33

3.4 Execution of the Experiment 34

3.4.1 Turning Process 34

3.4.2 Cutting Tool 36

3.4.3 Workpiece 37

3.4.4 Coolant 38

3.5 Data Collection 40

3.5.1 Surface Roughness 41

vii

3.5.2 Tool Wear 43

CHAPTER 4: RESULT AND DISCUSSION

4.1 Surface Roughness 44

4.2 Tool Wear 48

CHAPTER 5: CONCLUSION 53

5.1 Conclusion 53

5.2 Recommendation 54

5.3 Sustainability Element 54

REFERENCE 55

viii

LIST OF TABLES

2.1 Machining guideline for face turning duplex stainless steels 8

2.2 Recommended wear land size for different tool material and operations 18

2.3 Summary of studies on cutting fluid 26

3.1 Data collection for surface roughness 33

3.2 Data collection for tool wear 34

3.3 Specifications of Variable Speed Centre Lathe 35

3.4 Constant Parameters 36

3.5 Properties of TiAlN coating 36

3.6 Chemical composition of 2205 duplex stainless steel 37

3.7 Mechanical Properties at Room Temperature, ASTM A 240 37

3.8 Specification of Mitutoyo Profilometer SJ-301 42

ix

LIST OF FIGURES

2.1 Turning operation 6

2.2 Two-phase microstructure of austenite and ferrite grain in duplex

stainless steel 12

2.3 Coordinates used for surface roughness measurement 16

2.4 Standard terminology of surface finish 16

2.5 Traverse direction and stylus movement of surface roughness tester 17

2.6 Types of tool wear 17

2.7 Characterization of flank wear land and rake face wear crater according

to ISO standard 3685l 19

2.8 The variation of the flank wear rate with cutting time 20

2.9 Distribution of heat amongst the chip, workpiece and too 21

2.10 Vortex tube 24

2.11 The structure of the flow inside a counter flow vortex tube 24

2.12 Principal of multi-circulation inside vortex tube 25

3.1 Process flow 32

3.2 Variable speed centre lathe machine 35

3.3 TiAlN coated carbide tool 36

3.4 Flood coolant 38

3.5 Set up for chilled air coolant 39

x

3.6 Air compressor filter regulator 40

3.7 Measure the temperature using thermocouple thermometer 40

3.8 Mitutoyo Profilometer SJ-301 41

3.9 Setup of profilometer during surface roughness measurement 42

3.10 Scanning electron microscope 43

3.11 Maximum Flank Wear, VBmax 43

4.1 Surface roughness under all cutting conditions 45

4.2 Flank wear for all cutting conditions 49

4.3 Flank wear after machining with (a) chilled air coolant at 16°C, 51

(b) chilled air coolant at 14°C, (c) chilled air coolant at 12°C, and (d)

conventional coolant.

xi

LIST OF EQUATIONS

2.1 Formula of Cutting Speed (m/min) 7

2.2 Formula of Feed Rate (mm/min) 7

2.3 Formula of Depth of Cut (mm) 7

2.4 Arithmetic Mean Value (Ra) 16

3.1 Formula of Spindle Speed (rpm) 41

xii

LIST OF ABBREVIATIONS, SYMBOLS, AND

NOMENCLATURES

A. C. Alternate Current

ANOVA Analysis of Variance

ASTM America Standard Testing Material

BUE Built Up Edge

CNC Computer Numerical Control

CVD Chemical Vapor Deposition

D Diameter

DSS Duplex Stainless Steel

f Feed

ISO International Standard Organization

LN Liquid Nitrogen

MQL Minimum Quantity Lubricant

OHNS Oil Hardened Non Shrinkable

PVD Physical Vapor Deposition

Ra Roughness Average

RPM Revolution Per Minute

SEM Scanning Electronic Microscope

TiAlN Titanium Aluminium Nitride

xiii

TiC Titanium Carbide

TiCN Titanium Carbonitride

TiN Titanium Nitride

VBmax Maximum Flank Wear

Vc Cutting Speed

1

This chapter covers the introduction, problem statement, objectives, and scopes

of this project. The chapter overview is also included in this chapter.

1.1 Introduction

Duplex stainless steels (DSS) are chromium- nickel-molybdenum alloys that consist

of balanced amount of austenite and ferrite mixture. By comparing to austenitic

stainless steel alloy, the resistance to chloride stress corrosion cracking and the

mechanical properties of DSS alloys are much higher. DSSs are widely being used in

many industrial sectors like chemical and petrochemical, offshore, pharmaceutical

industry and marine industry.

Machining is a process in which the unwanted raw material is removed by using

sharp cutting tool in order to attain a desired geometry. There are several types of

machining processes such as turning, drilling and milling. Turning is a process where

the cutting tool is fed to a rotating workpiece to generate an external and internal

surface concentric with the axis of rotation. The machine tool used for turning is

called lathe. When the metal is cut, energy is dissipated in overcoming friction

between the tool and workpiece and in deformation of the chip. This energy is

converted to heat, this cause high temperature in the deformation zone as well as the

tool and workpiece. Therefore a cutting fluid or coolant is needed to reduce the

temperature (Stephenson & Agapiou, 2006).

INTRODUCTION

CHAPTER 1

2

Cutting fluid performance in the machining operation is important to enhance the

effectiveness of the machining process. The main purpose of cutting fluid is for

cooling and lubrication but it also helps in improving surface finish, increasing life

span of the cutting tool, and increasing the dimensional accuracy of the workpiece.

Other than that, cutting fluid is used to flush away the chips from the cutting zone,

increase the corrosion resistance of the workpiece and machine, and prevent

formation of build up edge (Johnson et al., 2014).

The general type of cutting fluid consist of water-soluble fluid, neat cutting oil and

gaseous. Water soluble fluids are preferable for operations where cutting speeds are

very high and pressures on the tool are relatively low. Neat cutting oils are straight

mineral oils, or mineral oils with additives which are suitable when the cutting

pressures between chip and cutting tool were very high. Lubrication is important to

reduce the cutting pressure at the cutting zone. At high cutting speed the cutting

fluids are unable to penetrate into the chip–tool interface. Gaseous lubricants are

preferable when the cutting fluid penetration problem is considered but the high cost

of gases made them uneconomical for production applications (Yildiz & Nalbant,

2008).

The use of cutting fluid is not only uneconomical for production application, but it

also harmful to environment as well as the health of the worker. These disadvantages

have made many companies seriously searching for an alternative to replace the

conventional flood coolant method. Therefore the study on chilled air coolant was

done to find the solution to this problem. Most of the works on low temperature

machining are in the cryogenic machining. Even though this is process is promising,

it is cost prohibited in most machining situations. The proposed research will utilize

passive cooling method using vortex tube to chill the compressed air. Since the

source of energy for this application coming from regular compressed air, the cost

associate with it is much lower than that of cryogenic cooling method (Rinaldy et al.,

2016).

3

1.2 Problem Statement

Coolant is important as it helps in increasing tool life and improves surface

roughness. However conventional flood coolant is uneconomical and it brings harm

to the environment and the human health. There were researches that have been done

on low temperature machining study such as cryogenic coolant but to implement this

type of coolant is quite expensive. Therefore, a research on chilled air liquid coolant

will be done to see its effect on the surface roughness and tool wear.

1.3 Objectives

The objectives of this project are:

To investigate the effect of chilled air coolant on surface roughness and tool

wear when machining 2205 duplex stainless steel.

To compare the machining performance between chilled air coolant and

conventional flooded coolant method.

1.4 Scope

This study is carried out using a vegetable oil coolant that is widely used in

machining. The process that is used is turning process, using the TiAlN coated

tungsten carbide grade. The workpiece material is 2205 duplex stainless steel. The

coolant methods that are used are chilled air coolant and flood coolant. The input

variables which are cutting speed, feed rate and depth of cut are set as the constant

parameter. The effect of chilled air coolant on the surface roughness and tool wear

when machining 2205 duplex stainless steel is studied and analysed in detail.

4

1.5 Chapter Overview

Chapter 1 covers the introduction of this investigation. It contains the general

information about the investigation, problem statement, objectives, and scope of the

project.

Chapter 2 covers the literature review for this pro. It contains the literature review for

turning, cutting fluid in turning, studies on cutting fluid and chilled coolant.

Chapter 3 contains the methodology of this project. It contains flow chart, literature

review, execution of the experiment, data collection and data analysis.

Chapter 4 contains the result and discussion for this project. The data from the

experiment is collected and analysed.

Chapter 5 covers the conclusion of this investigation. This chapter also covers the

recommendation for future work and sustainability of this investigation.

5

This chapter contains the literature review of the project which is related to the

objectives and scope of the project. This chapter also tells about the literature review

that will be used in this entire investigation.

2.1 Turning Process

Turning is one of the most basic machining operations. Turning is a very important

machining process in which a single point cutting tool removes unwanted material

from the surface of a rotating cylindrical work piece. The basic principle of turning

operation is shown in Figure 2.1. The cutting tool is fed linearly in a direction

parallel to the axis of rotation (Ozcelik et al., 2011). It can produce an internal or

external surface concentrically with the axis of rotation. The workpiece is clamped

on a rotating spindle using a chuck, collet, face plate, or between pointed conical

centers. The cutting tool is held on a turret on a translating carriage or in the

tailstock. The carriage moves along the bedways which is parallel to the part axis (Z-

axis) (Stephenson et al., 2006). It can be adjusted axially on the bedways to

accommodate workpieces of various lengths. The feed motion is usually parallel to

the axis of the workpiece.

LITERATURE REVIEW

CHAPTER 2

6

Figure 2.1: Turning operation (Tulasiramarao et al., 2013)

Turning is used to reduce the diameter of the workpiece usually to a specified

dimension, and to produce a smooth finish on the workpiece. Often the work piece

will be turned so that adjacent sections have different diameters (Khandey, 2009).

2.2 Machining Parameters

In turning, the main machining parameters are speed, feed and depth of cut. There

are other parameters or input factors that will influenced the output parameter such as

surface roughness and tool wear, however the control of those three parameters can

be adjusted during the turning operation (Agrawalla, 2014).

2.2.1 Cutting Speed

Cutting speed is the rate at which the part moves past the cutting tool. It is also

referred as surface speed. The spindle speed is the speed when the spindle rotates and

it is measured in revolution per minute. It is the basically the product of the rotating

speed times the circumference of the work piece before the cut is begun. It is only

referring to the work piece and is expressed in meter per minute (m/min). Cutting

speed will be different if the diameter of the workpiece is different, although the

rotating speed does not change.

7

Vc = 𝜋𝐷𝑁

1000 [2.1]

Vc is the cutting speed in turning, D is the initial diameter of the work piece in mm,

and N is the spindle speed in RPM (Agrawalla, 2014).

2.2.2 Feed Rate

Feed rate is the rate of the cutting tool moves through the material that is being cut.

The feed rate units depend on the motion of the tool and workpiece. When the

workpiece rotates, the units are almost distance per spindle revolution. It is usually

expressed in mm per revolution, or mm/rev.

Fm = f.N mm.min-1 [2.2]

Fm represents the feed in mm per minute, f is the feed in mm/rev and N is the spindle

speed in RPM (Khandey, 2009).

2.2.3 Depth of Cut

Depth of cut referred to the thickness of the material that is removed from the

workpiece. The diameter after machining is reduced by twice of the depth of cut due

to the removal of the material from both sides.

dcut = 𝐷−𝑑

2 mm [2.3]

D and d represent initial and final diameter (in mm) of the job respectively (Agrawalla, 2014).

2.2.4 Studies on Machining Parameter

Johnson et al. (2014) studied the optimization of the cutting parameters and fluid

application parameters while turning of Oil Hardened Non shrinkable steel (OHNS)

with minimal cutting fluid application using Taguchi technique. Three different