Chapter
1.3 Microforming Methods and Processes
1.3.1.1 Micro Cross Wedge Rolling
1.3.1.2 Micro Flexible Rolling
1.3.1.3 Micro Ultrathin Strip Rolling
1.3.3 Micro Hydromechanical Deep Drawing
1.3.6 Other Microforming Methods
2 Size Effects in Microforming
2.1 Categories of Size Effects
2.2 Problems Caused by Size Effects
2.2.1 Size Effects on Mechanical Behavior
2.2.2 Size Effects on Tribology
2.2.3 Size Effects on Scatter of Material Behavior
2.3 Strategies for Control of Size Effects
2.3.1 Microforming at Elevated Temperatures
2.3.1.2 Characteristics of Microforming at Elevated Temperatures
2.3.1.3 Heating Methods in Microforming
2.3.2 Microstructural Refinement
II. Theory of Microforming
3.2.1 Scaling of Length and Area in Two-Dimensional Geometry
3.2.2 Scaling of Surface Area and Volume in Three-Dimensional Geometry
3.3.1 Scaling in Dynamic Force
3.3.2 Scaling in Work and Power
3.4.1 Scaling in Bending Moment
3.4.2 Scaling in Deflection and Stiffness
3.5 Scaling in Hydrodynamics
3.6 Scaling in Heat Transfer
3.6.1 Scaling in Heat Conduction
3.6.2 Scaling in Heat Convection
3.6.3 Scaling in Heat Radiation
3.7 Scaling in Electromagnetic and Electrostatic Forces
3.7.1 Scaling in Electromagnetic Force
3.7.2 Scaling in Electrostatic Force
3.8 Scaling in Electricity
4 Strain Gradient Plasticity Theory
4.3 Phenomenological Strain Gradient Plasticity Theory
4.4 Mechanism-Based Strain Gradient Plasticity Theory
4.5 Conventional Theory of Mechanism-Based Strain Gradient Plasticity
5 Crystal Plasticity Theory
5.2 Crystal Plasticity Theory
5.2.1 Geometrics and Kinematics of Crystal Plastic Deformation
5.2.2 Rate Independent Crystal Plasticity Constitutive Equation
5.2.3 Rate Dependent Crystal Plasticity Constitutive Equation
5.3 Simplification of Rate Dependent Crystal Plasticity Theory
5.3.1 Decomposition of the Crystal Plastic Deformation Gradient
5.3.2 Elastic Constitutive Equation
5.3.3 Flow Rule of Plastic Deformation
5.3.4 Equation of Kinematics
5.3.6 Models of Polycrystal Homogenization
5.3.6.1 Taylor Averaging Procedure
5.3.6.2 Finite Element Averaging Procedure
5.4 Numerical Integration of Rate Dependent Crystal Plasticity Theory
5.4.1 Total Lagrangian Formulation
5.4.2 Fully Implicit Integration Procedure
5.5 Calculation of Grain Orientation
5.6 Crystal Plasticity Finite Element Method in ABAQUS
5.6.2 Flowchart of Crystal Plasticity Finite Element Method in ABAQUS
III. Simulation of Microforming Process
6 Simulation Models in Microforming
6.4.2 Implementation of Two-Dimensional Voronoi Diagram in ABAQUS/CAE
6.4.3 Implementation of Three-Dimensional Voronoi Diagram in ABAQUS/CAE
7 Simulation of Micro Cross Wedge Rolling
7.2 Simulation Procedure of MCWR
7.3.1 Forming Angle α and Stretching Angle β
7.3.3 Strain and Stress During MCWR
7.3.4 Size Effects in MCWR Process
7.3.5 Influence of Temperature on the Surface Asperity in MCWR
8 Simulation of Micro Flexible Rolling
8.2.1 Theory Analysis of Flexible Rolling Process
8.2.1.3 Length of Arc of Contact
8.2.2 Numerical Simulation of Micro Flexible Rolling Process
8.2.2.3 Material Heterogeneity
8.2.3 Simulation of Springback
8.2.4 Modeling of Surface Roughness Deformation
8.3.1 Springback Analysis
8.3.1.1 Influence of Tension on Average Springback
8.3.1.2 Scatter of Springback for Initial Workpiece Thickness of 250μm
8.3.1.3 Comparison of Scatter of Springback for Different Initial Workpiece Thicknesses
8.3.1.4 Quantitative Prediction of Springback in Thickness Direction
8.3.2 Surface Roughness Evolution
8.3.2.1 Effect of the COF
8.3.2.2 Influence of Rolling Speed
8.3.2.3 Effect of Roll Gap Adjusting Speed
8.3.2.4 Effect of Reduction and Initial Surface Roughness
9 Simulation of Micro Ultrathin Strip Rolling
9.2.1 Theory Analysis of Ultrathin Strip Rolling
9.2.2 Two-Dimensional Foil Rolling Modeling
9.2.3 Surface Roughness Modeling in FEM
9.3.1 Two-Dimensional Foil Rolling Simulation
9.3.1.1 Contact Pressure and Roll Contour in Roll Bite
9.3.1.2 Effect of Entry Thickness
9.3.1.4 Effect of Reduction Rate in Roll Bite
9.3.2 Simulation in Surface Roughness Evolution
9.3.2.1 Asymmetrical Rolling Analysis
9.3.2.2 Effect of Roll Materials
9.3.2.3 Real Contact Area Evolution
9.3.2.4 Surface Roughness Evaluation During Rolling
9.3.2.5 Rolling Characterization of Asymmetrical Rolling
10 Simulation of Micro Deep Drawing
10.2 Simulation Procedure
10.2.3 Voronoi Models With Consideration of Surface Roughness
10.2.4 Microstructural Images–Based Modeling
10.3.1 Drawn Cup Thickness Comparison
10.3.2 Springback and Shape Quality Comparison
10.3.3 Fracture and Earing in Micro Deep Drawing
11 Simulation of Micro Hydromechanical Deep Drawing
11.2 Simulation Procedure
11.2.2 Surface Layer Modeling
11.2.3 Open and Closed Lubrication Modeling
11.3.1 Friction Size Effects
11.3.2 Effect of Hydraulic Pressure
11.3.3 Wrinkling and Earing
12 Simulation of Micro Bending
12.2 Simulation Procedure
12.2.1.2 Micro Tensile Tests
12.2.2 Voronoi Tessellation Implement in ABAQUS
12.2.3 Grain Heterogeneity
12.2.4 Numerical Simulation Procedure
12.3.2 Simulation Verification
12.3.2.1 Micro V-Bending Experimental Results
12.3.2.2 Comparison between Experimental and Simulation Results
13 Simulation of Micro Compression
13.2 Simulation Procedure
13.2.1 Material Constitutive Model
13.2.1.2 Constitutive Model Considering Temperature
13.2.1.3 Surface Layer Model
13.2.1.4 Grain Heterogeneity
13.2.2 Finite Element Model Setup
IV. Practice of Microforming
14 Practice of Micro Cross Wedge Rolling
14.1 Equipment and Tools for Micro Cross Wedge Rolling
14.1.1 Design of MCWR Machine
14.1.2 MCWR Forming Process
14.1.3 Design of Forming Tool
14.2 Micro Cross Wedge Rolling Practice
14.2.1 Surface Roughness Analysis
14.2.2 Springback of Micro-Metal Workpiece in MCWR
15 Practice of Micro Flexible Rolling
15.1 Equipment and Tools for Micro Deep Drawing
15.2 Micro Flexible Rolling Practice
15.2.2 Materials and Rolling Procedure
15.2.3 Experimental Methodology
15.2.4 Results and Discussion
15.2.4.1 Microstructural Evolution
15.2.4.2 Tensile Properties
16 Practice of Micro Ultrathin Strip Rolling
16.1 Equipment and Tools for Micro Ultrathin Strip Rolling
16.2 Micro Ultrathin Strip Rolling Practice
16.2.2 Rolled Material Profile Analysis
16.2.3 Lubrication Effect
16.2.3.1 Oil Lubrication in Metal Forming
16.2.3.2 Mix Lubricant Analysis
16.2.3.3 Oil Film Thickness
16.2.3.4 Rolling Parameters for Various Rolling Conditions
16.2.3.5 Surface Topography Analysis After Micro Rolling
17 Practice of Micro Deep Drawing
17.1 Equipment and Tools for Micro Deep Drawing
17.1.2 Micro Tensile Tests
17.1.3 Equipment of Micro Deep Drawing
17.2 Micro Deep Drawing Practice
17.2.1 Microstructure Effect
17.2.2 Effect of Lubrication
17.2.3 Punch Diameter Influence and Size Effects
17.2.4 Initial Gap Influence
17.2.5 Thickness Size Effects
18 Practice of Micro Hydromechanical Deep Drawing
18.1 Equipment and Tools for Micro Hydromechanical Deep Drawing
18.1.1 Design of MHDD Apparatus
18.1.2 Hydraulic Equipment
18.1.3 Determination of Tool Dimensions
18.2 Micro Hydromechanical Deep Drawing Practice
18.2.1 Effect of Counter Pressure in MHDD
18.2.2 Tribological Behavior in MHDD
18.2.2.1 Friction Model in MHDD
18.2.2.2 Required Fluid Pressure for Hydrodynamic Lubrication
18.2.2.3 Comparison of Tribological Behavior in MHDD and Conventional HDD
18.2.2.4 Analytical Conditions
18.2.2.5 Experiment of MHDD
18.2.2.6 Results and Analysis
18.2.2.6.1 Model Validation
18.2.2.6.2 Effect of Fluid Pressure on Drawability in HDD and MHDD
18.2.2.6.3 Effect of Relative Punch Diameter to Thickness on Fluid Behavior
18.2.2.7 Verification and Size Effects Prediction on Lubricated OLPs by Fluid Pressure in MHDD
18.2.2.8 Evaluation Test for OLPs Utilizing Liquid
18.2.2.9 Lubrication Model by Fluid Pressure in MHDD
18.2.2.10 Discussion on Lubricated OLPs by Fluid Pressure in MHDD
18.2.2.10.1 Appearance of OLPs in Fluid Medium
18.2.2.10.2 Friction Force of Lubricated OLPs by Fluid Pressure
18.2.3 Effect of Microstructure in MHDD
19 Practice of Micro Bending
19.2 Micro Bending Practice
19.2.1 Material Preparation
19.2.2 Micro V-bending Setup
19.2.3 Texture Acquisition
19.3.1 Effect of T/D on Recrystallization Texture
19.3.2 Effect of T/D on Deformation Texture in Micro V-bending
19.3.3 Effect of T/D on {110} Texture in Micro V-bending
20 Practice of Micro Compression
20.2 Micro Compression Practice
20.2.1 Material Preparation
20.2.2 Micro Compression Setup
20.2.3 Laser Heating Strategy
20.2.3.1 Laser Heating Equipment
20.2.3.2 Laser Heating Practice
Microforming Technology
：Theory, Simulation and Practice
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