EVALUATION OF NICKEL ELECTROLESS PLATING ON MILD STEEL MOHD RIDZWAN BIN ADNAN. Thesis submitted in fulfillment of the requirements

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1 EVALUATION OF NICKEL ELECTROLESS PLATING ON MILD STEEL MOHD RIDZWAN BIN ADNAN Thesis submitted in fulfillment of the requirements for the award of the degree of Bachelor of Mechanical Engineering Faculty of Mechanical Engineering UNIVERSITI MALAYSIA PAHANG DECEMBER 2010

2 ii UNIVERSITI MALAYSIA PAHANG FACULTY OF MECHANICAL ENGINEERING I certify that the thesis entitled Evaluation of Nickel Electroless Plating on Mild Steel is written by Mohd Ridzwan Bin Adnan. I have examined the final copy of this thesis and in my opinion; it is fully adequate in terms of scope and quality for the award of the degree of Bachelor of Mechanical Engineering. I herewith recommend that it be accepted in fulfillment of the requirements for the degree of Bachelor of Mechanical Engineering. LUQMAN HAKIM BIN AHMAD SHAH Examiner: Signature

3 iii SUPERVISOR S DECLARATION I hereby declare that I have checked this project and in my opinion, this project is adequate in terms of scope and quality for the award of the degree of Bachelor of Mechanical Engineering. Signature: Name of Supervisor: DAYANGKU NOORFAZIDAH BINTI AWANG SH RI Position: LECTURER Date: 06 DECEMBER 2010

4 iv STUDENT S DECLARATION I hereby declare that the work in this project is my own except for quotations and summaries which have been duly acknowledged. The project has not been accepted for any degree and is not concurrently submitted for award of other degree. Signature: Name: MOHD RIDZWAN BIN ADNAN ID Number: MA08007 Date: 06 DECEMBER 2010

5 vi ACKNOWLEDGEMENTS I am grateful and would like to express my sincere gratitude to my supervisor Mrs. Dayangku Noorfazidah binti Awang Sh ri for her germinal ideas, invaluable guidance, continuous encouragement and constant support in making this research possible. She has always impressed me with her outstanding professional conduct, her strong conviction for science and material, and her belief that a degree program is only a start of a long-time learning experience. I appreciate her consistent support from the first day I applied to graduate program to these concluding moments. I am truly grateful for her progressive vision about my training in science and material, her tolerance of my naïve mistakes, and her commitment to my future career. I also sincerely thank her for the time spent proofreading and correcting my many mistakes. My sincere thanks go to all my labmates and members of the staff of the Mechanical Engineering Department, UMP, who helped me in many ways and made my stay at UMP pleasant and unforgettable. Many special thanks go to member science and material research group for their excellent co-operation, inspirations and supports during this study. I acknowledge my sincere indebtedness and gratitude to my parents for their love, dream and sacrifice throughout my life. I also gratefully acknowledge the assistance of everybody who helped in the execution of this project in UMP. Special thanks to Mr. Basirul Subha Bin Alias as the PSM coordinator, who has given some advice and share his knowledge on this PSM. I would like to acknowledge their comments and suggestions, which was crucial for the successful completion of this study.

6 vii ABSTRACT Nickel electroless plating on mild steel is carried out by a chemical reaction and without the use of an external source of electricity. In nickel electroless plating, nickel chloride will come as a metallic salt and is reduced by using Sodium hypophosphite as the reducing agent to nickel metal, which then is deposited on the mild steel. In this experiment, the effect of solution concentration on thickness and mechanical properties of nickel plating on mild steel using electroless plating process was investigated. The solutions used in this experiment were Sodium hypophosphite and nickel chloride.with varying concentration. Electroless plating were done for 30 days. Then the surface structure and morphology nickel plating was evaluated using scanning electron microscopy (SEM), Optical Microscope while its hardness was evaluated using Vickers hardness test. In electroless plating, anode is the movements of negative ions toward the positive electrode and the mild steel as the cathode because the movement of positive ions toward the negative electrode. Electroless plating found the coating thickness by effected of percentage of concentration of solution, effect of thickness of coating to the mechanical properties and anode and cathode weight loss in electroless plating. The size of sample specimen is 0.05 m of length, 0.03 m of width and m of thickness for both of mild steel and nickel sheet metal. The machine that was applied in the experiment were, shearing machine to cut the mild steel into size, drilling machine to make a hole to the surface of mild steel and nickel, micro vickers hardness test machine to get a mechanical properties behavior to mild steel after electroless plating and scanning electron microscopy (SEM) to get the microstructure observation of sample after electroless plating. The highest coating thickness is at 252 µm corresponding to percentage of concentration solution of 22.2 % at sample 8 followed by 19.4 %, 16.7 %, 13.9 %, 11.1 %, 8.3 %, 5.6 %, and 2.8 % for sample 7, 6, 5, 4, 3, 2, and 1. When the percentage of concentration of solution is increase, the hardness value of mild steel is decrease while the coating thickness increases. So, the grain size of microstructure will increase while increase the percentage of concentration of solution.

7 viii ABSTRAK Penyaduran nikel kurang elektro pada keluli tulen (mild steel) dilakukan oleh reaksi kimia dan tanpa menggunakan sumber tenaga elektrik sebagai agen luar. Dalam penyaduran nikel kurang elektro, Nikel klorida akan datang sebagai garam metalik dan dikurangkan dengan menggunakan Natrium hipofosfit sebagai agen pengurangan untuk logam nikel, yang kemudian disimpan dalam keluli tulen. Pada eksperimen ini, pengaruh konsentrasi larutan terhadap ketebalan dan sifat mekanik pelapisan nikel pada keluli tulen dengan menggunakan proses penyaduran atau pelapisan kurang elektro diselidiki. Serbuk larutan yang digunakan dalam penyaduran ini adalah Natrium hipofosfit dan nikel klorida dengan pelbagai kepekatan. Penyaduran kurang elektro dilakukan selama 30 hari. Kemudian struktur permukaan dan morfologi penyaduran nikel dinilai menggunakan Pengimbasan Mikroskop Elektron (SEM), Mikroskop optikal manakala kekerasannya dinilai dengan menggunakan ujian kekerasan Vickers. Dalam penyaduran kurang elektro, Anod adalah pergerakan ion negatif terhadap elektrod positif dan keluli tulen sebagai katod kerana pergerakan ion positif terhadap elektrod negatif. Hal ini di sebabkan ketebalan lapisan mempengaruhi peratusan kepekatan larutan, pengaruh ketebalan lapisan terhadap sifat mekanik dan kehilangan berat pada katod dan katod pada penyaduran kurang elektro. Saiz sampel spesimen adalah 0.05 m panjang, 0.03 m lebar dan m tebal untuk kedua keluli tulen dan kepingan logam nikel. Mesin yang digunakan dalam eksperimen adalah, mesin pemotong untuk memotong keluli tulen mengikut ukuran, mesin gerudi untuk membuat lubang pada permukaan keluli tulen dan nikel, mesin ujian kekerasan vicker mikro untuk mendapatkan perilaku sifat mekanik untuk keluli tulen selepas penyaduran kurang elektro dan Pengimbasan Mikroskop Elektron (SEM) di gunakan untuk mendapatkan pemerhatian mikrostruktur pada sampel selepas penyaduran kurang elektro. Ketebalan lapisan tertinggi pada 252 µm sesuai dengan peratusan kepekatan larutan sebanyak 22,2 % pada sampel 8 diikuti oleh 19.4 %, 16,7 %, 13,9 %, 11,1 %, 8,3 %, 5,6 %, dan 2.8 % untuk sampel 7, 6, 5, 4, 3, 2, dan 1. Apabila peratusan konsentrasi larutan bertambah, nilai kekerasan untuk keluli tulen akan berkurang sementara meningkatkan ketebalan lapisan. Jadi, saiz butiran mikro akan meningkat sementara meningkatnya peratusan kepekatan larutan.

8 ix TABLE OF CONTENTS APPROVAL DOCUMENTS SUPERVISOR S DECLARATION STUDENT S DECLARATION DEDICATION ACKNOWLEDGEMENTS ABSTRACT ABSTRAK TABLE OF CONTENTS LIST OF TABLES LIST OF FIGURES LIST OF SYMBOLS LIST OF ABBREVIATIONS Page ii iii iv v vi vii viii ix xiii xiv xvii xviii CHAPTER 1 INTRODUCTION 1.1 Project Background Problem Statement Project Objectives Project Scope of Work Significance of The Study Project Flow Diagram Project Flow Details Project Task (Gantt Chart) 7 CHAPTER 2 LITERATURE REVIEW 2.1 Introduction Current Existing Electroless Plating Sample Origin of Electroless Nickel, History and Basic Theory 9

9 x Interpretation of Electroless Plating Electroplating Process Coating Technologies Mechanical Properties of Nickel Electroless Plating Parameter Included In Nickel Electroless Plating Types of Chemical Type of Material Common Material Plated Applications of Electroless Nickel Plating Pretreatment of Parts for Electroless Nickel Plating Advantages of Electroless Nickel Plating Disadvantages of Electroless Nickel Plating Time Uses In Electroless Nickel Plating For Corrosion Resistance For Wear Resistance in Hard to Reach Areas Types of Electroless Nickel Plating Nickel Phosphorus Baths Nickel-Boron Baths Polyalloys Composite Coatings Scanning Electron Microscopy (SEM) Conclusion 32 CHAPTER 3 RESEARCH METHODOLOGY 3.1 Introduction Process Flow Diagram Specimen Preparations Type of Metal that were Used Size of Sheet Metal Quantity Needed in Experiment Items of Solution Type of Solution that were Used Concentration of Solution Preparation of Solution Apparatus and Instrument Preparation Apparatus that Apply 41

10 xi Instrument Preparations Overall Experiment Configuration Design of Experiment (DOE) General Flow of Experiment Step-by-Step of Procedure Conclusion 57 CHAPTER 4 RESULTS AND DISCUSSION 4.1 Introduction Before Electroless Plating Process Important Aspect Weight Measurement Process Anode and Cathode Weight Loss in Electroless Plating Material Characterization Microstructure Observation Microstructure Observation for Mild Steel After 66 Electroless Plating Process Nickel Coating Surface Morphology Grain Boundaries Structure of Mild Steel on The Surface after Electroless Plating Process Evaluation of Effect of Percentage of Concentration Effect of Percentage of Concentration of Solution to the 70 Thickness of Coating Effect of Coating Thickness to the Mechanical properties 77 CHAPTER 5 CONCLUSION AND RECOMMENDATIONS 5.1 Introduction Conclusions Recommendation 80 REFERENCES 82 APPENDIXS 84 A Data of important aspect before electroless nickel plating process 84 B Data for measuring the mass of powder before electroless plating process 85

11 xii C Data for mixture of distilled water + sodium hypophosphite + nickel chloride before electroless plating process 86 D Data for weight after electroless plating process 88 E Data for comparing the reading of Mild Steel and Nickel before and after electroless plating process 89 F G (a) (h) Data for Reading of Mild steel by using Micro Vickers Hardness Test (HV) Metallurgical microscope grain boundary structure for specimen 1 until specimen H Overall experiment setup for electroless plating process 99

12 xiii LIST OF TABLES Table No. Title Page 2.1 Coating processes used to protect functional surfaces Properties of sodium phosphinate The experiment s essentials in electroless plating The sample preparation of electroless plating process Measuring the weight of powder (Sodium Hypophosphite & Nickel Chloride 4.3 Amounts for each sample specimen before electroless plating process 4.4 Comparing the weight of Mild Steel and Nickel before and after Electroless plating The percent of weight loss of mild steel and nickel The thickness of coating with fix of time to plating (30 day) Reading of mild steel by using micro vickers hardness test (HV) Etching used for low carbon steel Data of important aspect before electroless nickel plating process Data for measuring the mass of powder before electroless plating process 6.3 Data for mixture of distilled water + sodium hypophosphite + nickel chloride before electroless plating process Data for weight after electroless plating process Data for comparing the reading of Mild Steel and Nickel before and after electroless plating process 6.6 Data for Reading of Mild steel by using Micro Vickers Hardness Test (HV) 89 90

13 xiv LIST OF FIGURES Figure No. Title Page 1.1 Project flow diagrams Project gantt chart Examples of electroformed Microstructures Schematic of electroplating process Order in which dissimilar metals produce electromotive-force (Galvanic) series Chemical reaction of sodium phosphinate Evo 50 type of common SEM machine in industries Schematic diagram of SEM Process flow diagram Sample of mild steel sheet metal Sample of nickel sheet metal Sketching for Size of specimen Size of specimen Sample powder of sodium hypophosphite and its colour Sample powder of nickel chloride and its colour Sample of 500ml glass beaker Sample of commonly electronic wire Sample of stick Evo 50 type of Common SEM machine Sample 5 during electroless plating Schematic diagram of nickel electroless plating on mild steel 45

14 xv 3.14 General flow of experiment Cutting process Drilling process Filing process Measurement process The specimens before added to the distilled water The specimens after added to the distilled water Vickers hardness test (HV) Mounting process Grinding and polishing process Etching process Etching time and place to etching process Observation process by using metallurgical microscope Observation process by using optical microscope The weighted loss of mild steel and nickel after electroless plating The sample 8 of mild steel in electroless plating process, (a) before; (b) after 4.3 The sample of microstructure observation after electroless plating for sample SEM surface morphology of nickel electroless plating The surface of mild steel by using metallurgical microscope Difference micrographs showing grain boundaries SEM coating surface thickness (material; mild steel): (a) Specimen 1 (1780x); (b) Specimen 2 (1960x) 4.8 SEM coating surface thickness (material; mild steel): (c) Specimen 3 (1280x); (d) Specimen 4 (555x) 71 72

15 xvi 4.9 SEM coating surface thickness (material; mild steel): (e) Specimen 5 (810x); (f) Specimen 6 (1000x) 4.10 SEM coating surface thickness (material; mild steel): (g) Specimen 7 (720x); (h) Specimen 8 (570x) 4.11 Effect of percentage of concentration of solution on coating thickness 4.12 Effect of coating thickness to the hardness mechanical properties of mild steel Metallurgical microscope grain boundary structure for specimen Metallurgical microscope grain boundary structure for specimen Metallurgical microscope grain boundary structure for specimen Metallurgical microscope grain boundary structure for specimen Metallurgical microscope grain boundary structure for specimen Metallurgical microscope grain boundary structure for specimen Metallurgical microscope grain boundary structure for specimen Metallurgical microscope grain boundary structure for specimen Before Mix with Distilled water After Mix with Distilled water and ready to electroless plating process 99

16 xvii LIST OF SYMBOLS HV e Micro Vickers Hardness Electron µ Micron Vpn g/cm 3 calcm/sec/ C plated Density Heat of conductivity C Temperature NiP 3 Mpa NaPO 2 H 2 NiCl 2 VHN m mol/l ml Nickel phosphide Mega Pascal Sodium hypophosphite Nickel Chloride Composite coating Distance Concentration of solution Volume % Percentage g s weight time

17 xviii LIST OF ABBREVIATIONS ASTM CVD DOE EN EQN FYP NC PSM PVD SEM SH UMP American Society for Testing and Materials Chemical vapour deposition Design of experiment Electroless nickel Equation Final year project Nickel chloride Projek sarjana muda Pysical vapour deposition Scanning electron microscopy Sodium hypophosphite Universiti Malaysia Pahang

18 1 CHAPTER 1 INTRODUCTION 1.1 PROJECT BACKGROUND This project title is Evaluation of Nickel Electroless Plating on Mild Steel. This experiment is intended to see the chemical reaction of mild steel by using chemicals that differs in kind of effect to the coating thickness. Electroless plating is an autocatalytic process where the substrate develops a potential when it is dipped in electroless solution called bath which contains a source metal of metallic ions, reducing agent, stabilizer and others. Due to the developed potential, both positive and negative ions are attracted towards the substrate surface and release their energy through charge transfer process. Each process parameter has its specific role on the process and influences the process response variables. Temperature initiates the reaction mechanism which controls the ionization process in the solution and charge transfer process from source to substrate. In addition to this, the substrate is activated before dipping into the electroless bath and sensitized to initiate the charge transfer process. Actually in electroless metal deposition process, no external current supply is required to deposit material on a substrate. Electroless deposition has the advantages of simplicity and feasibility over other processes. The amorphous boron is introduced to improve the adherence between coating and the substrate besides improving properties, like wear resistance, hardness, corrosion resistance and surface roughness. The applications of electroless nickel have been reported in many industries, like petroleum, chemical, plastics, optics, aerospace, nuclear, electronic devices, computer, and printing because of its excellent corrosion and wear resistance properties. This experiment should be carried out at various

19 2 conditions of temperature and environments, and the same time to see the reaction simultaneously in mild steel. 1.2 PROBLEM STATEMENT For this evaluation, current process of nickel electroless plating on mild steel is considered to be around 20 to 40 days (Rossi, 2003) to get some of coating on material. The experiment was divided into 8 unit. It was conducted with constant time to get different thicknesses for each of the electroless plating. In addition, different type of material to coat has a different of microstructure after electroless plating on market. One of the most effects to focus during screening the surface is morphology test by using SEM (scanning electron microscope). All specimens are rectangular in shape with 0.05 m x 0.03 m x m in size. But for the future improvement during electroless plating process, it required to use various types of shape on specimen with various time coating. 1.3 PROJECT OBJECTIVES Basically this project is based on these two objectives: To evaluate the effect of nickel electroless plating on mild steel. To study the result of electroless plating by using morphology analysis on mild steel. 1.4 PROJECT SCOPE OF WORK In this study, the experiment or analysis test will be held in the Material Laboratory and the area of UMP. This process is carried out by a chemical reaction and without the use of an external source of electricity. The scopes of the study are as follows:- a) For the test in the laboratory, the Sodium hypophosphite is consider to use as the reducing agent to nickel metal and nickel chloride as a metallic salt, which then is deposited on the work piece. It is mainly used for electroless nickel plating

20 3 and with this method, a durable nickel-phosphorus film can coat objects with irregular surfaces, and can widely be used ionics, aviation and the petroleum field. b) Use the nickel metal as Anode (positive terminal) and a piece of mild steel as a Cathode (negative terminal) in Sodium hypophosphite. c) Plating area will conduction in Material Laboratory at UMP by following a parameter that needed. d) Parameters that will be analyzed is a constant coating time during conducts the electroless plating, concentration of solution (contents, mol and ph) and types of solution that use during electroless plating process (fix and constant). 1.5 SIGNIFICANCE OF THE STUDY Electroless nickel (EN) plating is a chemical reduction process that depends upon the catalytic reduction process of nickel ions in an aqueous solution (containing a chemical reducing agent) and the subsequent deposition of nickel metal without the use of electrical energy. Thus in the Electroless nickel plating process, the driving force for the reduction of nickel metal ions and their deposition is supplied by a chemical reducing agent in solution. This driving potential is essentially constant at all points of the surface of the component, provided the agitation is sufficient to ensure a uniform concentration of metal ions and reducing agents. The electroless deposits are therefore very uniform in thickness all over the part s shape and size. The process thus offers distinct advantages when plating irregularly shaped objects, holes, recesses, internal surfaces, valves, threaded parts, and so forth. Electroless as autocatalytic nickel coating provides a hard, uniform, corrosion-, abrasion-, and wear-resistant surface to protect machine components in many industrial environments. EN is chemically deposited, making the coating exceptionally uniform in thickness. Careful process control can faithfully reproduce the surface finish, eliminating the need for costly machining after plating.

21 4 In a true electroless plating process, reduction of metal ions occurs only on the surface of a catalytic substrate in contact with the plating solution. Once the catalytic substrate is covered by the deposited metal, the plating continues because the deposited metal is also catalytic. As a result, electroless plating processes are widely used in industry to meet the end-use functional requirements and are only rarely used for decorative purposes. Electroless plating is ideal for the salvage of miss-machined parts & recycling worn components and it can reduce wear and corrosion. Besides, electroless plating can be hardened on metal that using and it can change magnetic tendency of a substrate. Electroless nickel plating also can reduce galling and frictional resistance. It also can be soldered easily. Other than that, Electroless Nickel provides lubricity and functional release properties, making it ideal plating for dies, gears, and molds. It can also be used as a cost effective measure to repair and salvage molds.

22 5 1.6 PROJECT FLOW DIAGRAM Start Gather information Collection information Analysis on Parameter Experiment preparation Polishing process Immersion test Morphology test Analysis on physical properties Discussion Documentation End Figure 1.1: Project flow diagrams

23 6 1.7 PROJECT FLOW DETAILS When look on the project flow diagram, the experiment starts with gathering the information on related of journals, magazines, books, and surfing the internet to get a literature review and research on these title which is evaluation of Nickel Electroless plating on Mild Steel. For this part, it focuses more to the function and the parameter that using in the experiment. This is want to know and review of the design of experiment and previous research in market. Alls the resources should be follow the standard likes American Society for Testing and Material (ASTM). ASTM is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services. After all of that, the experiment undergoes to the collect of information that focus on the objective. In this step, the main focus is about the parameters which are type of chemical that use, mechanical properties, the meaning of Electroless plating and Electroplating, and previous research but the more focus is on the coating effect to the mild steel. For the next step, setup the experiment by following the available of parameter. The parameter is like the type of chemical reagant, size of mild steel, quantity of mild steel will apply and the time that will consider during experiment. In this step, all parameters represent the number of making the experiment. Later, on testing method, the design of experiment must be consider evaluating of nickel electroless plating on mild steel such as a mechanical properties and microstructure of mild steel before and after the plating process. For the microstructure of mild steel, the thickness of coating should be considered on before and after the experiment. The experiment undergoes to the next step which call as analysis. For this step, all parameter that want to evaluate must following the standard. In this step, the result will be focus and make a comparison between actual and plan. Choose a good of result and give a reason to the comparing. For this also focus on the parameter that follow

24 7 such as a hardness of mild steel before and after experiment to look about a coating. In analysis, all result can be show on related diagram, chart, graph and table. Finally, when all the process mentioned above is done, the material for report writing is gathered. The report writing process will be guided by the UMP PSM report writing guide. This process also included the presentation slide making for the mid and final presentation of the project. The project ended after the submission of the report and the presentation slide has been presented on the last of semester study. 1.8 PROJECT TASK (GANTT CHART) Figure 1.2: Project gantt chart