Unconventional. Machining Processes. M. Adithan ATLANTIC PUBLISHERS & DISTRIBUTORS (P) LTD

Transcription

1 Unconventional M. Adithan ATLANTIC PUBLISHERS & DISTRIBUTORS (P) LTD

2 Contents Preface v Introduction 110 Need of Unconventional 1 Characteristic Features of Modern 1 Processes Basic Principle of New Methods 4 Advantages of NonTraditional 6 Processes Limitations of NonTraditional 7 Processes Classification of New Methods 8 Abbreviations used for Unconventional 9 Methods Electrical Discharge 1157 (EDM) Introduction 11 Operating Principles of Spark Erosion 12 Nature of the Machined Surface 13 Tool Materials used in Spark Erosion 15 Dielectric Fluid 15 Basic Circuit used for Spark Erosion 16 Construction Details of Spark Erosion Machines 17 The Relaxation Generators 20 Rotary Impulse Generators 22 Static Impulse Generators 22

3 xij Characteristics of an Impulse Generator 24 Comparison of Relaxation Generator and 27 Impulse Generator Important Features of Modern Spark Erosion 28 Machines Attachments 31 Control Panel 32 Practical Aspects of Spark Erosion 33 Metal Removal Rates and Accuracy of Holes 34 Obtained in EDM Applications and Uses of Spark Erosion Machines 38 General Rules for Application 39 Advantages of Spark Erosion 39 Disadvantages of Spark Erosion 42 Recent Trends in EDM Process 43 ElectroDischarge Sawing Machine 45 Features/Advantages of the ElectroDischarge 47 Sawing Process Applications of ElectroDischarge Sawing 47 Travelling Wire Spark (TWEDM) Erosion Machine 50 Review Questions in EDM 53 ElectroChemical (ECM) Introduction 58 Principle of ECM Process 58 Typical Engineering Materials that can be 59 machined by ECM Process Different Variations of Electrolytic Methods of 60 ECM Process Details 61 Typical Conditions in ECM 64 Chemical Reactions that occur in ECM 67 Features of the ECM Process 68 Power Supply Requirements for ECM 69

4 In In Xiii Electrolytes used in ECM 70 Factors governing the choice of Electrolyte 70 Velocity of Electrolyte 72 Tool Materials used in ECM 74 Process Variables and Characteristics in ECM 74 Tool Design for ECM 75 Surface Finish Obtainable in ECM 78 Effect of ECM on the Mechanical Properties the Workpiece Advantages of Electrochemical of 78 Process 79 Disadvantages of Electrochemical 80 Problems Encountered in the Application of ECM 81 Points to be considered for the Successful 83 Application of ECM Process General Applications of ECM 84 Die Working 85 of Aeroengine Components 86 Electrochemical Shaping of Aeroengines, 91 Turbine Blades Economics of Electrochemical 94 Ranking Chart for ECM Applications 97 General Comparison between Spark Erosion 100 (EDM) and Electrochemical (ECM) Detailed Comparison of EDM and ECM 101 Recent Developments in Electrochemical 106 (ECM) Process Electrochemical Deburring (ECD) 108 Electroforming Combining Process 112 USM and ECM 113 Review Questions in Electrochemical 115 Electrochemical Grinding (ECG) 124

5 xiv Description of the ECG Process 124 Electrolyte 126 Types of ECG Operations 127 Constructional Details of Diamond Wheels used 128 in ECG Manufacturing of Diamond Wheels 130 Designation of Diamond Wheels 130 Conditions in ECG 132 Metal Removal Rate in ECG 132 Advantages of the ECG Process 133 Disadvantages or Limitations of Electrolytic 134 Grinding (ECG) Fields of Applications Metallurgical Aspects of ECG 135 to be Considered 136 Important Points to be Observed During the 137 ECG Process Performance Characteristics of ECG Process 138 Types of Grinding Wheels Used in ECG 141 Electrochemical Discharge Grinding (ECDG) 141 Advantages of Electrochemical Discharge 141 Grinding Process Electrolytic Sawing 142 Electrochemical Honing (ECH) 142 ElectroPolishing (ELP) 143 Advantages of ElectroPolishing 144 Review Questions in Electrochemical 144 Grinding (ECG) 4. Electron Beam (EBM) Introduction 146 Description of the Process 146 Need for a High Vacuum in EBM 148 Applications of Electron Beam 149

6 XV Process Parameters in Hole Drilling by Electron 151 Beam Machine Advantages of Electron Beam 151 Disadvantages or Limitations of EBM 153 Electron Beam Welding and its Applications 153 Metals Welded by Electron Beam 156 Advantages of Electron Beam Welding 156 Economics of the Electron Beam Welding 156 Ion Beam (IBM) 157 Review Questions in Electron Beam 157 Laser Beam (LBM) 158 Introduction 158 Lasing Process 158 Laser System 159 Thermal Effect on Workpiece 167 Calculation of Material Removed in Laser 167 Mechanism of Material Removal 168 Description of Laser Drilling Machine 169 Applications of Laser 170 Cost Factors in the Application of Laser 170 Recent Developments in Laser 171 Advantages of Laser Beam 172 Disadvantages or Limitations of Laser Beam 173 Laser Welding Process 174 Review Questions in Laser Beam 175 Plasma ARC (PAM) 176 Introduction 176 Types of Plasma Arc 177 Stabilized Arc 178

7 High Transducer Trunk Tool Abrasive Workpiece xvi Mechanism of Plasma Torch 179 Plasma Torch for Turning Operation 181 Influence of Different Parameters in Plasma Arc 181 Points to be Observed While Using a Plasma 183 Torch on a Lathe Plasma Spraying 185 Applications and Advantages of Plasma Spraying 187 Recent Developments in Plasma Jet Cutting 188 Review Questions in Plasma Arc Ultrasonic (USM) Introduction 191 Basic Principle of the Process 191 Ultrasonic Drilling Machines 194 Essentials of the Ultrasonic Drilling Process 194 Frequency Oscillating Current Generator Slurry Performance of the USD Process 211 Mechanism of Metal Removal in Ultrasonic 213 Drilling Characteristics of the Surface Finish Formed 214 Influence of Static Load on the Rate 215 in USD Methods of Controlling the Static Load 216 Hollow Tools Vs. Solid Tools 220 Technological Applications of Ultrasonic 220 Industrial Applications of USM 225 Materials that can be Machined by Ultrasonic Drilling 228

8 NonSelective Selective xvii Advantages of Ultrasonic Drilling Process 230 Limitations of Ultrasonic (USM) 231 Methods of Improving Process the Performance of USD 232 Applications of Ultrasonic Vibrations in Other 233 Applications of Ultrasonic Vibrations in Other 235 Metal Working Processes General Advantages with Ultrasonic Vibrations 237 Review Questions in Ultrasonic Drilling Abrasive Jet (AJM) Process Description 246 Features of Abrasive Jet 246 Practical Applications of AJM Process 248 Advantages of AJM Process 249 Disadvantages of AJM Process 249 Abrasive Polishing 250 Hydrodynamic (HDM) 251 Water Jet (WJM) 251 Review Questions in AJM & WJM Chemical (Chemilling) (CHM) Introduction 254 Basic Techniques of CHM 255 MetalRemoval 255 MetalRemoval 256 Steps involved in Chemical Milling (Chemilling) 257 Mechanism of Metal Removal 259 Process Variables 261 Advantages of the Process 262 Applications of CHM 264 Recent Developments in CHM 264

9 xviii Review Questions in Chemical Comparison of Unconventional Introduction 268 Physical Parameters of the Modern 271 Methods Important Application Areas for Nontraditional 272 Effect of Nonconventional Material Removal 273 Processes on the Surface Integrity Machined of the Materials Factors which constitute Surface Integrity 274 Importance of Surface Integrity General Review Questions in Unconventional Objective Type Questions in Unconventional Processes Key to Objective Type Questions 294 Index 295