基于油包水工作液的绿色高效电火花成形加工(英文版)

ForewordPrefaceChapter 1 Dehydration efficiency of high-frequency pulsed DC electrical fields on water-in-oil emulsion1．1 Introduction1．2 Model development1．2．1 Define of emulsion stability index1．2．2 Define of dehydration efficiency index1．3 Experiments1．3．1 Preparation of emulsion1．3．2 Experimental instrumentation1．3．3 Relationship between conductivity and measured current1．4 Results and discussion1．4．1 The relationship between measured current and droplets behaviour1．4．2 Influence of the inter-electrode distance1．4．3 Influence of the frequency1．4．4 Influence of the pulse duration1．4．5 Influence of the water contents1．4．6 Influence of surfactant concentration1．4．7 Influence of initial droplets size1．4．8 Influence of sodium chloride concentration in the dispersed phase1．4．9 Influence of temperature1．5 ConclusionsChapter 2 Simulation of droplet behavior in water-in-oil emulsion subjected to an electric field2．1 Introduction2．2 Kinetic modeling of droplets2．2．1 Forces acting on droplets2．2．2 Electric forces2．2．3 Viscous forces2．2．4 Coulomb force and gravity2．3 Simulation2．3．1 Assumptions2．3．2 Coalescence probability2．3．3 Simulation strategy2．4 Experiments2．5 Results and discussion2．6 ConclusionsChapter 3 Application of variable frequency technique on electrical dehydration of water-in-oil emulsion3．1 Introduction3．2 Experiments3．2．1 Preparation of emulsion3．2．2 Experimental instrumentation3．2．3 Define of dehydration efficiency index3．3 Results and discussion3．3．1 The relationship between measured current and droplets behaviour3．3．2 Dehydration efficiency of the pulsed electric field with constant frequency3．3．3 Dehydration efficiency of the pulsed electric field with changing frequency3．4 ConclusionsChapter 4 Discussion of the drop rest phenomenon at millimeter scale and coalescence of droplets at micrometer scale4．1 Introduction4．2 Theory4．2．1 Stochastic model for the drop-interface and droplet-droplet coalescence4．2．2 Model for the droplets behavior in electric field based on conductivity technique4．3 Materials and methods4．3．1 Materials and preparation of W／O emulsions4．3．2 Experimental conditions4．3．3 Experiments on the measurement of surface and interfacial tension4．3．4 Experiments on interfacial coalescence of drops4．3．5 Experiments on droplets coalescence in pulsed DC electric filed4．4 Results and discussion4．4．1 Adsorption at water-oil interfaces4．4．2 Interfacial coalescence of drops4．4．3 Emulsion stability in pulsed DC electric filed4．5 ConclusionsChapter 5 Investigation of the charging characteristics of micron sized droplets based on parallel plate capacitor model5．1 Introduction5．2 Principle5．3 Experimental section5．4 Results and discussion5．4．1 Validation of the method5．4．2 Influence of electrical field strength and ion species5．4．3 Influence of electrolyte concentration5．4．4 Influence of droplets size5．5 Comparison with high electrical field strength5．6 ConclusionsChapter 6 Investigation on the influence of the dielectrics on the material removal characteristics of EDM6．1 Introduction6．1．1 Type of currently used dielectrics6．1．2 Role of the dielectrics6．1．3 Investigation strategy of this work6．2 Experimental work6．2．1 Experimental set-up6．2．2 Experimental procedure6．2．3 Rebuilt of the crater with 3D-CAD software6．3 Results and discussion6．3．1 Definition of the crater shape6．3．2 Diameter， depth and volume6．3．3 Removal efficiency6．3．4 Transient simulation of the discharge generated bubble6．4 ConclusionsChapter 7 Transient dynamics simulation of the electrical discharge generated bubble in sinking EDM7．1 Introduction7．2 Transient dynamics modeling7．2．1 Assumptions7．2．2 Model and boundary conditions7．2．3 Modeling of the bubble7．2．4 Governing equation7．3 Discussion of the simulation7．3．1 Propagation of the blast wave7．3．2 Pressure at the center of the discharge spot on the workpiece's surface7．3．3 Force applied on the electrodes7．3．4 Velocity field in the gap7．4 Experiments and results7．4．1 Shape characters of discharge crater7．4．2 Volume of removed material and removal efficiency7．4．3 Vibration intensity of workpiece7．5 ConclusionsChapter 8 A novel method of determining energy distribution and plasma diameter of EDM8．1 Introduction8．2 Energy distribution model of EDM8．2．1 Principle8．2．2 Heat conduction analysis8．3 Experimental work8．4 Results and discussion8．4．1 Determination of Xdeb8．4．2 Determination of Xcon and Rpe8．4．3 Influence of polarity and dielectric8．4．4 Comparison with previous researches and discussion8．5 ConclusionsChapter 9 Sinking EDM in water-in-off emulsion9．1 Introduction9．2 Experiments and methods9．2．1 Preparation of emulsion9．2．2 Viscosity of emulsion9．2．3 Experimental set-up9．3 Results and discussion9．3．1 Comparison of EDM machining characteristics using kerosene and W／O emulsion at different peak currents9．3．2 Comparison of kerosene and W／O emulsion at different pulse durations9．4 Discussion of the gap phenomenon9．5 ConclusionsChapter 10 Study of the recast layer of a surface machined by sinking EDM using water-in-off emulsion as dielectrics10．1 Introduction10．2 Experimental procedures10．3 Results and discussion10．3．1 SR and RLT10．3．2 Oxide existed in the recast layer10．3．3 XRD measurement10．3．4 EDS measurement10．3．5 Micro-cracks and micro-voids in the recast layer10．3．6 Micro hardness10．4 ConclusionsReferences