Foreword
Preface
Chapter 1 Dehydration efficiency of high-frequency pulsed DC electrical fields on water-in-oil emulsion
1．1 Introduction
1．2 Model development
1．2．1 Define of emulsion stability index
1．2．2 Define of dehydration efficiency index
1．3 Experiments
1．3．1 Preparation of emulsion
1．3．2 Experimental instrumentation
1．3．3 Relationship between conductivity and measured current
1．4 Results and discussion
1．4．1 The relationship between measured current and droplets behaviour
1．4．2 Influence of the inter-electrode distance
1．4．3 Influence of the frequency
1．4．4 Influence of the pulse duration
1．4．5 Influence of the water contents
1．4．6 Influence of surfactant concentration
1．4．7 Influence of initial droplets size
1．4．8 Influence of sodium chloride concentration in the dispersed phase
1．4．9 Influence of temperature
1．5 Conclusions
Chapter 2 Simulation of droplet behavior in water-in-oil emulsion subjected to an electric field
2．1 Introduction
2．2 Kinetic modeling of droplets
2．2．1 Forces acting on droplets
2．2．2 Electric forces
2．2．3 Viscous forces
2．2．4 Coulomb force and gravity
2．3 Simulation
2．3．1 Assumptions
2．3．2 Coalescence probability
2．3．3 Simulation strategy
2．4 Experiments
2．5 Results and discussion
2．6 Conclusions
Chapter 3 Application of variable frequency technique on electrical dehydration of water-in-oil emulsion
3．1 Introduction
3．2 Experiments
3．2．1 Preparation of emulsion
3．2．2 Experimental instrumentation
3．2．3 Define of dehydration efficiency index
3．3 Results and discussion
3．3．1 The relationship between measured current and droplets behaviour
3．3．2 Dehydration efficiency of the pulsed electric field with constant frequency
3．3．3 Dehydration efficiency of the pulsed electric field with changing frequency
3．4 Conclusions
Chapter 4 Discussion of the drop rest phenomenon at millimeter scale and coalescence of droplets at micrometer scale
4．1 Introduction
4．2 Theory
4．2．1 Stochastic model for the drop-interface and droplet-droplet coalescence
4．2．2 Model for the droplets behavior in electric field based on conductivity technique
4．3 Materials and methods
4．3．1 Materials and preparation of W／O emulsions
4．3．2 Experimental conditions
4．3．3 Experiments on the measurement of surface and interfacial tension
4．3．4 Experiments on interfacial coalescence of drops
4．3．5 Experiments on droplets coalescence in pulsed DC electric filed
4．4 Results and discussion
4．4．1 Adsorption at water-oil interfaces
4．4．2 Interfacial coalescence of drops
4．4．3 Emulsion stability in pulsed DC electric filed
4．5 Conclusions
Chapter 5 Investigation of the charging characteristics of micron sized droplets based on parallel plate capacitor model
5．1 Introduction
5．2 Principle
5．3 Experimental section
5．4 Results and discussion
5．4．1 Validation of the method
5．4．2 Influence of electrical field strength and ion species
5．4．3 Influence of electrolyte concentration
5．4．4 Influence of droplets size
5．5 Comparison with high electrical field strength
5．6 Conclusions
Chapter 6 Investigation on the influence of the dielectrics on the material removal characteristics of EDM
6．1 Introduction
6．1．1 Type of currently used dielectrics
6．1．2 Role of the dielectrics
6．1．3 Investigation strategy of this work
6．2 Experimental work
6．2．1 Experimental set-up
6．2．2 Experimental procedure
6．2．3 Rebuilt of the crater with 3D-CAD software
6．3 Results and discussion
6．3．1 Definition of the crater shape
6．3．2 Diameter， depth and volume
6．3．3 Removal efficiency
6．3．4 Transient simulation of the discharge generated bubble
6．4 Conclusions
Chapter 7 Transient dynamics simulation of the electrical discharge generated bubble in sinking EDM
7．1 Introduction
7．2 Transient dynamics modeling
7．2．1 Assumptions
7．2．2 Model and boundary conditions
7．2．3 Modeling of the bubble
7．2．4 Governing equation
7．3 Discussion of the simulation
7．3．1 Propagation of the blast wave
7．3．2 Pressure at the center of the discharge spot on the workpiece's surface
7．3．3 Force applied on the electrodes
7．3．4 Velocity field in the gap
7．4 Experiments and results
7．4．1 Shape characters of discharge crater
7．4．2 Volume of removed material and removal efficiency
7．4．3 Vibration intensity of workpiece
7．5 Conclusions
Chapter 8 A novel method of determining energy distribution and plasma diameter of EDM
8．1 Introduction
8．2 Energy distribution model of EDM
8．2．1 Principle
8．2．2 Heat conduction analysis
8．3 Experimental work
8．4 Results and discussion
8．4．1 Determination of Xdeb
8．4．2 Determination of Xcon and Rpe
8．4．3 Influence of polarity and dielectric
8．4．4 Comparison with previous researches and discussion
8．5 Conclusions
Chapter 9 Sinking EDM in water-in-off emulsion
9．1 Introduction
9．2 Experiments and methods
9．2．1 Preparation of emulsion
9．2．2 Viscosity of emulsion
9．2．3 Experimental set-up
9．3 Results and discussion
9．3．1 Comparison of EDM machining characteristics using kerosene and W／O emulsion at different peak currents
9．3．2 Comparison of kerosene and W／O emulsion at different pulse durations
9．4 Discussion of the gap phenomenon
9．5 Conclusions
Chapter 10 Study of the recast layer of a surface machined by sinking EDM using water-in-off emulsion as dielectrics
10．1 Introduction
10．2 Experimental procedures
10．3 Results and discussion
10．3．1 SR and RLT
10．3．2 Oxide existed in the recast layer
10．3．3 XRD measurement
10．3．4 EDS measurement
10．3．5 Micro-cracks and micro-voids in the recast layer
10．3．6 Micro hardness
10．4 Conclusions
References
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