Machining of Titanium Alloys (Materials Forming, Machining and Tribology)

"This book presents a collection of examples illustrating the resent research advances in the machining of titanium alloys. These materials have excellent strength and fracture toughness as well as low density and good corrosion resistance; however, machinability is still poor due to their low thermal conductivity and high chemical reactivity with cutting tool materials. This book presents solutions to enhance machinability in titanium-based alloys and serves as a useful reference to professionals and researchers in aerospace, automotive and biomedical fields." -- Font no determinada Preface 5 Contents 6 1 Machinability and Machining of Titanium Alloys: A Review 7 Abstract 7 1.1...Introduction 7 1.2...Overview of Machinability of Titanium Alloys 8 1.2.1 Cutting Tool Materials and Wear Mechanisms When Machining Titanium Alloys 9 1.2.2 Part Quality and Surface Finish When Machining Titanium Alloys 11 1.2.3 Cutting Forces When Machining Titanium Alloys 12 1.2.4 Chip Formation 13 1.2.5 Other Main Machinability Criteria: Residual Stress, Burr Formation and Particle Emission 18 1.3...Microstructural Aspects During Machining of Titanium Alloys 18 1.4...Effects of Lubrication/Coolant Modes 19 1.5...Case Study: Metallic Particle Emission During Turning of Ti-6A-14V Titanium Alloy 21 1.6...Introduction 21 1.7...Experimental Plan 22 1.8...Results 22 1.9...Discussion 25 1.10...Conclusion 27 References 28 2 Cutting Tool Materials and Tool Wear 37 Abstract 37 2.1...Introduction 37 2.2...What is Titanium? 38 2.3...Metallurgy of Titanium and Its Alloys 40 2.3.1 Alpha ( alpha ) Alloys 40 2.3.2 Near Alpha Alloys 41 2.3.3 Alpha-Beta ( alpha + beta ) Alloys 42 2.3.4 Metastable Beta ( beta ) Alloys 42 2.3.5 Beta ( beta ) Alloys 42 2.3.6 Titanium Aluminides 42 2.4...Titanium as a Hard-to-Cut Material 43 2.4.1 Poor Thermal Conductivity 45 2.4.2 Low Modulus of Elasticity and the Consequent Springback 46 2.4.3 Chemical Reactivity 47 2.4.4 Hardening due to Diffusion and Plastic Deformation 47 2.4.5 Mechanism of Chip Formation 48 2.5...Cutting Tools: Historical Background and Chronological Advances 49 2.6...Application of HSS Tools in Machining Titanium and Its Alloys 53 2.7...Application of Carbide Tools in Machining Titanium and Its Alloys 54 2.8...Application of Ceramic Tools in Machining Titanium and Its Alloys 56 2.9...Application of CBN Tools in Machining Titanium and Its Alloys 58 2.10...Application of PCD Tools in Machining Titanium and Its Alloys 59 2.11...Conclusion 60 References 60 3 Mechanics of Titanium Machining 63 Abstract 63 3.1...Introduction 64 3.2...Mechanics of Orthogonal Cutting 66 3.3...Five Axis Ball End Milling Operation 70 3.3.1 Kinematics of the Process 70 3.3.2 Simulation and Experiment 72 3.3.3 Results 74 3.4...Micro Ball End Milling of Titanium 76 3.4.1 Kinematics of the Process 76 3.4.2 Simulation and Experimental Results 79 3.5...Conclusion 82 References 82 4 Analysis of Physical Cutting Mechanisms and Their Effects on the Tool Wear and Chip Formation Process When Machining Aeronautical Titanium Alloys: Ti-6Al-4V and Ti-55531 85 Abstract 85 4.1...Introduction 86 4.2...Experimental Procedure 87 4.2.1 Workpiece Material 87 4.2.2 Cutting Tools 89 4.2.2.1 Cutting Tool Material 89 4.2.2.2 Cutting Tool Geometries 91 4.2.3 Cutting Parameters 91 4.2.4 Thermal Characterization of Titanium Alloys 92 4.2.4.1 Temperature Measurements 92 4.2.4.2 Thermal Conductivity Measurements 93 4.2.5 Monitoring of the Chip Formation Process 94 4.3...Results and Discussion 94 4.3.1 Effect of the Tool Geometry 95 4.3.1.1 Effect on Cutting Forces 95 4.3.1.2 Effect on Friction at the Tool/Chip Interface 97 4.3.1.3 Effect on the Specific Energy in Machining 99 4.3.2 Effect of Coating on Machinability 100 4.3.3 Effect of Lubrication on Machinability 102 4.3.4 Review of Chips 102 4.3.4.1 Chip Morphology of Titanium Alloys Ti-6Al-4V and Ti-55531 103 4.3.4.2 Chip Microstructure of Titanium Alloys Ti-6Al-4V and Ti-55531 105 4.3.5 Wear Mechanisms of Cutting Tools 106 4.3.5.1 Study of the Worn Tool-Chip Contact Length 107 4.3.5.2 Tool Wear Analyses 108 4.4...Conclusion 115 References 116 5 Green Machining of Ti-6Al-4V Under Minimum Quantity Lubrication (MQL) Condition 118 Abstract 118 5.1...Introduction 118 5.2...Milling Force and Temperature Model 119 5.2.1 Dynamic Force in End Milling 119 5.2.1.1 Friction Force 119 5.2.1.2 Equivalent Cutting Edge Model 121 5.2.1.3 Transformation Between Measuring Force and Dynamic Milling Force 121 5.2.2 Milling Heat and Temperature 123 5.2.2.1 Heat Generation 123 5.2.2.2 Heat Dissipation 123 5.3...Comparison of Effects with Different MQL System Parameters 124 5.3.1 Milling Experimental Procedures Using MQL System 124 5.3.1.1 Workpiece Material 124 5.3.1.2 Milling Experiment and MQL Supply Device 125 5.3.1.3 Milling Test Procedures 125 5.3.2 Effects of MQL System Parameters 127 5.3.2.1 Influence of Air-Pressure 127 5.3.2.2 Influence of Spray-Distance 129 5.3.2.3 Influence of Oil-Quantity 129 5.3.2.4 Influence of Spray-Angle 131 5.4...Conclusions 132 Acknowledgements 132 References 132 6 Ultrasonically Assisted Machining of Titanium Alloys 135 Abstract 135 6.1...Introduction 135 6.2...Ultrasonically Assisted Machining 136 6.2.1 Experimental Setup 137 6.2.2 Case Study 1: Ti-15-3-3-3 138 6.2.2.1 Work-Piece Material 138 6.2.2.2 Experimental Studies and Machining Results 138 6.2.2.3 Results: Cutting Forces 140 6.2.2.4 Results: Surface Topography 142 6.2.2.5 Results: Sub-Surface Analysis 142 6.2.3 Case Study 2: Ti-6-2-4-6 144 6.2.3.1 Work-Piece Material 144 6.2.3.2 Experimental Studies and Machining Results 144 6.2.3.3 Results: Cutting Forces 144 6.2.3.4 Results: Surface Topography 145 6.3...Discussion 145 6.4...Hot Ultrasonically Assisted Machining 146 6.4.1 Experimental Setup and Methodology 146 6.4.2 Experimental Studies and Machining Results 147 6.4.3 Results: Measurements of Cutting Forces and Temperature 147 6.4.4 Results: Surface Topography 148 6.5...Discussion 150 6.6...Conclusions and Outlook 150 References 151 Index 152 Front Matter....Pages i-vii Machinability and Machining of Titanium Alloys: A Review....Pages 1-30 Cutting Tool Materials and Tool Wear....Pages 31-56 Mechanics of Titanium Machining....Pages 57-78 Analysis of Physical Cutting Mechanisms and Their Effects on the Tool Wear and Chip Formation Process When Machining Aeronautical Titanium Alloys: Ti-6Al-4V and Ti-55531....Pages 79-111 Green Machining of Ti-6Al-4V Under Minimum Quantity Lubrication (MQL) Condition....Pages 113-129 Ultrasonically Assisted Machining of Titanium Alloys....Pages 131-147 Erratum to: Machinability and Machining of Titanium Alloys: A Review....Pages E1-E1 Back Matter....Pages 149-150 "This book presents a collection of examples illustrating the recent research advances in the machining of titanium alloys. ... This book presents solutions to enhance machinability in titanium-based alloys and serves as a useful reference to professionals and researchers in aerospace, automotive and biomedical fields." -- Page 4 of cover