TITANIUM DIOXIDE (TiO2) SOL GEL COATING ON 316L STAINLESS STEEL NORHASLINA ABDUL AZIZ A thesis submitted in partial fulfillment of the requirement for the award of the Degree of Master of Engineering Faculty of Mechanical and Manufacturing Engineering Universiti Tun Hussein Onn Malaysia 2014 ABSTRACT The work presented in this thesis deals with experimental and theoretical studies related to titanium dioxide (TiO ) thin films. The main purpose of this research is to 2 prepare the TiO sol gel coating on 316L stainless steel with the effect of withdrawal 2 speed and heat treatment. The whole project is emphasis on composition of TiO 2 coating on 316L stainless steel and how it affected by the different withdrawal speed and heat treatment temperature. The parameters used in this study are calcination temperature (300°C, 500°C and 700°C) and withdrawal speed (6mm/min, 30mm/min and 60mm/min). The coatings were obtained by the sol-gel method. Titanium (IV) butoxide was used as a TiO precursor in the sol gel process. Stainless steel 316L was 2 coated with dip coating method. In this experiment, the characteristics of the TiO 2 sol-gel coating on 316L stainless steel were investigated using Fourier transform infrared spectroscopy (FTIR) for structural/bonding determination, X-ray diffraction (XRD) for phase determination and Scanning electron microscopy (SEM) for morphology of the sample. Then, corrosion behavior of the sample was obtained by electrochemistry test. The coating was examined in 3.5% NaCl at room temperature (25±0.2°C). In the solution examined, anatase crystallite exist at calcined temperature 500°C while rutile crystallite at 700°C. The value of corrosion rate increased as the calcined temperature increased and the best protective properties exhibit at 300°C and withdrawal speed 60 mm/min. The result shows that as calcined temperature increased, the corrosion rate increased and the corrosion current density decreased gradually. Other than that, as the withdrawal speed increased, the films particles become more compact and also the grain size become more distinct. vi ABSTRAK Kajian yang dibentangkan di dalam tesis ini adalah berkenaan dengan eksperimen dan teori yang berkaitan dengan filem nipis titanium dioksida (TiO ). Tujuan utama 2 kajian ini adalah untuk menyediakan salutan sol gel TiO pada 316L keluli tahan 2 karat dengan kesan kelajuan pengeluaran dan rawatan haba. Keseluruhan kajian ini menunjukkan komposisi lapisan salutan TiO pada 316L keluli tahan karat dan 2 bagaimana ia dipengaruhi oleh kelajuan pengeluaran dan rawatan haba pada suhu yang berbeza. Parameter yang digunakan dalam kajian ini adalah suhu pengkalsinan (300°C, 500°C dan 700°C) serta kelajuan pengeluaran (6mm/min, 30mm/min dan 60mm/min). Lapisan diperolehi dengan kaedah sol-gel. Titanium (IV) butoxide digunakan sebagai pelopor TiO dalam proses sol gel. Keluli tahan karat 316L telah 2 disalut dengan kaedah salutan celup. Dalam eksperimen ini, ciri-ciri lapisan sol-gel TiO pada 316L keluli tahan karat telah diperolehi menggunakan spektroskopi 2 inframerah transformasi Fourier (FTIR) untuk penentuan struktur / ikatan, pembelauan sinar-X (XRD) untuk penentuan fasa dan mikroskop imbasan elektron (SEM) untuk morfologi sampel. Kemudian, kakisan sampel itu didapati dengan ujian elektrokimia. Lapisan ini telah dikaji pada 3.5% NaCl dan suhu bilik (25 ± 0.2°C). Dalam kajian yang diperolehi, hablur anatase wujud pada suhu 500°C manakala hablur rutil pada 700°C. Nilai kadar kakisan meningkat apabila suhu rrawatan haba meningkat dan hasil salutan sol gel terbaik adalah pada 300°C dan kelajuan pengeluaran 60mm/min. Hasil kajian menunjukkan apabila suhu rawatan haba meningkat, kadar kakisan juga meningkat dan ketumpatan kakisan menurun secara beransur-ansur. Selain daripada itu, apabila kelajuan pengeluaran meningkat, zarah filem nipis menjadi lebih padat dan juga saiz bijian menjadi berbeza. CONTENTS TITLE i DECLARATION ii DEDICATION iii ACKNOWLEDGEMENT iv ABSRACT v ABSTRAK vi CONTENTS vii LIST OF TABLES xii LIST OF FIGURES xiii LIST OF SYMBOLS xviii LIST OF APPENDIX xx CHAPTER 1 INTRODUCTION 1 1.1 Project background 1 1.2 Problem statement 2 1.3 Objectives 3 1.4 Scopes of study 4 1.5 Significance of study 4 CHAPTER 2 LITERATURE REVIEW 5 2.1 Introduction to thin film 5 2.1.1 Thin film growth 6 2.1.2 Thin film thickness 7 2.2 Thin film deposition 10 2.2.1 Physical deposition 10 2.2.2 Chemical deposition 12 2.2.3 Chemical solution deposition / 15 sol-gel 2.2.3.1 Sol-gel dip coating 16 2.2.3.2 Sol-gel densification 19 2.3 Introduction to TiO 23 2 2.3.1 TiO crystalline 22 2 2.3.2 Physical and mechanical properties 26 of TiO 2 2.4 Introduction to stainless steel 316L 27 2.4.1 Composition of stainless steel 316L 28 2.4.2 Physical and mechanical properties 29 of stainless steel 316L 2.5 Theory of corrosion 29 2.5.1 Types of corrosion 31 2.5.2 Electrochemical basis of corrosion 35 ix 2.5.3 Quantitative corrosion theory 39 2.5.4 Polarization resistance 41 2.6 X-Ray diffraction (XRD) 42 2.7 Scanning electron microscopy (SEM) 44 2.8 Fourier Transform Infrared spectroscopy 46 (FTIR) CHAPTER 3 METHODOLOGY 48 3.1 Introduction 48 3.2 Schematic flow chart of the project 50 3.3 Substrate preparation 51 3.3.1 Cutting Specimen 51 3.3.2 Rough Grinding 52 3.3.3 Polishing 52 3.3.4 Soldering and painting 53 3.4 Sol gel TiO formulation 53 2 3.5 Sol gel dip coating to produce thin films 54 of TiO 2 3.6 Heat treatment process 56 3.7 Thin film characterization 56 3.7.1 Fourier transform infrared (FTIR) 57 3.7.2 X-ray diffraction (XRD) 58 3.7.3 Scanning Electron Microscopy 58 Observation (SEM) x 3.8 Corrosion Test 60 3.8.1 Corrosion analysis 60 3.8.2 IVMAN Software 61 CHAPTER 4 RESULT AND ANALYSIS 62 4.1 Introduction 62 4.2 Structural characterization by X-Ray 62 diffraction 4.2.1 Effect of calcination temperature to 63 the structural characterization 4.2.2 Effect of withdrawal speed on the 67 structural characterization 4.3 Structure of molecules by Fourier Transform 69 Infrared (FTIR) spectroscopy 4.3.1 Effect of withdrawal speed and 69 calcination temperature 4.4 Corrosion rate of stainless steel 316L coating 72 with TiO 2 4.4.1 Effect of calcination temperature 72 to the corrosion rate 4.4.2 Effect of withdrawal speed to the 73 corrosion rate 4.5 Surface morphology by Scanning Electron 74 Microscopy (SEM) xi 4.5.1 Effect of calcination temperature to 75 the surface morphology 4.5.2 Effect of withdrawal speed to the 75 surface morphology CHAPTER 5 CONCLUSION AND RECOMMENDATION 82 5.1 Introduction 82 5.2 Suggestion for future work 84 REFERENCES 85 APPENDICES 92 A Gantt chart Master’s project 1 92 B Gantt chart Master’s project 1 93 xii LIST OF TABLES 2.1 Mechanical and physical properties of TiO 26 2 2.2 Environmental properties of TiO 27 2 2.3 Composition of stainless steel 316L 28 2.4 Mechanical and physical properties of stainless steel 316L 29 3.1 Weight ratio for TiO solution 54 2 4.1 Comparison of corrosion rate SS 316L coating with 71 TiO at different calcined temperature and withdrawal speed 73 2 4.2 Comparison of MPY with equivalent Metric-Rate expressions 74 4.3 Summarize of relative resistance condition for SS 316L coating 74 with TiO at different calcined temperature and withdrawal speed 2 xiii LIST OF FIGURES 2.1 Structure of thin film 5 2.2 Three modes of thin film growth process 7 2.3 Thickness in microns against viscosity in cP for sol-gel thin films 8 2.4 Film thickness against volume percent of TEOS 9 2.5 Thickness against viscosity and speed 10 2.6 Physical vapor deposition process 11 2.7 Sputtering method 12 2.8 Schematic of electroplating process 13 2.9 Spin coating process 14 2.10 Schematic of CVD process 15 2.11 Schematic representation of the sol gel process 16 2.12 Stages of the dip coating process 17 2.13 Schematic of the sol gel preparation of a thin film by dip coating 17 2.14 Schematic drawing of the withdrawal process 18 2.15 Change in fractional thickness as a function of densification 20 temperature
Description: