Selective Laser Sintering Additive Manufacturing Technology

Title-page_2021_Selective-Laser-Sintering-Additive-Manufacturing-Technology
Selective Laser Sintering Additive Manufacturing Technology
Copyright_2021_Selective-Laser-Sintering-Additive-Manufacturing-Technology
Copyright
Contents_2021_Selective-Laser-Sintering-Additive-Manufacturing-Technology
Contents
Foreword_2021_Selective-Laser-Sintering-Additive-Manufacturing-Technology
Foreword
Introduction_2021_Selective-Laser-Sintering-Additive-Manufacturing-Technolog
Introduction
Chapter-1---Equipment-and-con_2021_Selective-Laser-Sintering-Additive-Manufa
1 Equipment and control system
1.1 Composition of selective laser sintering equipment system
1.2 Temperature control system of the selective laser sintering equipment
1.2.1 Composition of the temperature control system
1.2.2 Temperature control algorithms
1.2.2.1 Development of temperature control algorithms
1.2.2.2 Preheating temperature adaptive control algorithm based on slice information
1.2.2.3 Specific implementation of algorithm
1.2.3 Analysis of temperature control stability
1.2.4 Actual cases
1.3 Galvanometer-type scanning system
1.3.1 Design and optimization of the galvanometer-type laser scanning system
1.3.1.1 Basic theory of galvanometer-type laser scanning system
1.3.1.1.1 Laser properties of galvanometer-type laser scanning system
Laser focusing properties
Focal depth of laser focusing
1.3.1.1.2 Beam expansion of laser of galvanometer-type laser scanning system
1.3.1.1.3 Focusing system for galvanometer-type laser scanning system
Preceding-objective scanning method
Postobjective scanning method
1.3.1.2 Mathematical model of galvanometer-type laser scanning system
1.3.1.2.1 Mathematical model of galvanometer-type laser preceding-objective scanning method
1.3.1.2.2 Mathematical model of galvanometer-type laser postobjective scanning method
1.3.1.3 Design and error correction of galvanometer-type laser scanning system
1.3.1.3.1 System constitution of galvanometer-type laser scanning system
Servo motor and servo drive of the system
Reflector
Dynamic focusing system for galvanometer-type laser scanning system
1.3.1.3.2 Scanning control of galvanometer-type laser scanning system
Interpolation algorithm
Data processing
1.3.1.3.3 Error analysis of galvanometer-type laser scanning system
1.3.1.3.4 Error correction of scan pattern of galvanometer-type laser scanning system
Shaping of scan pattern
Shape correction of graphics
Multipoint correction model
Application of multipoint calibration model
1.3.1.4 Summary
1.3.2 Design of scanning control card for galvanometer-type laser scanning system
1.3.2.1 Architecture of scanning control card
1.3.2.2 Hardware architecture of scanning control card system
1.3.2.2.1 Universal scanning control card
PCI interface chip
Peripheral interface chip
1.3.2.2.2 FPGA–based scanning control card
Design of FIFO in data transmission process
1.3.2.2.2.1 Scanning state and interrupt control
1.3.2.3 Driver of scanning control card
1.3.2.3.1 I/O port
1.3.2.3.2 Interrupt routines
1.3.2.4 Summary
1.3.3 Automation control and system monitoring of selective laser sintering system
1.3.3.1 Movement control system of selective laser sintering system
1.3.3.1.1 Powder feeding system
1.3.3.1.2 Powder laying system
1.3.3.2 Temperature control of selective laser sintering system
1.3.3.2.1 Temperature control strategy
1.3.3.2.2 Temperature control algorithm
1.3.3.3 Scanning system of selective laser sintering system
1.3.3.3.1 Scanning parameters
1.3.3.3.2 Monitoring of scanning system
1.3.3.4 Summary
1.3.4 Verification of running test of galvanometer scanning and selective laser sintering system
1.3.4.1 Scanning test and accuracy correction of scanning system
1.3.4.1.1 Scan test
1.3.4.1.2 Accuracy correction
1.3.4.2 System automation and running monitoring
1.3.4.2.1 Powder laying movement
1.3.4.2.2 Preheating control
1.3.4.2.3 State monitoring
1.3.4.3 Model making experiment
1.3.4.3.1 Main experimental equipment
1.3.4.3.2 Model making
1.3.4.4 Summary
Reference
Further reading
Chapter-2---Software-algorithm-a_2021_Selective-Laser-Sintering-Additive-Man
2 Software algorithm and route planning
2.1 STereo Lithography file fault tolerance and rapid slicing algorithm
2.1.1 Error analysis on STereo Lithography files
2.1.1.1 Cracks and loopholes
2.1.1.2 Irregular body
2.1.2 Fault-tolerant slicing strategy for STereo Lithography File
2.1.2.1 Preserving the original information of the STereo Lithography model at the maximum by modeling errors
2.1.2.2 Contour trimming on 2D level to reduce dimension of complex 3D model problems
2.1.2.3 Utilization of information in fault-tolerant slices
2.1.3 Algorithm implementation
2.1.3.1 Topology reconstruction algorithm
2.1.3.2 Slicing algorithm
2.1.4 Time and space complexity analysis of algorithm
2.1.4.1 Time complexity analysis of algorithm
2.1.4.2 Memory space complexity analysis
2.1.5 Measured performance of algorithm
2.1.6 Summary
2.2 STereo Lithography research and implementation on Boolean operation of STereo Lithography model
2.2.1 STereo Lithography definition and rule for STereo Lithography mesh model
2.2.2 Regularized set operation principle for 3D entity
2.2.2.1 Definition of regular set
2.2.2.2 Formulas for Boolean operation of regular set
2.2.3 STereo Lithography implementation of Boolean operation on STereo Lithography model
2.2.4 STereo Lithography file storage format
2.2.5 STereo Lithography topology reconstruction of STereo Lithography model
2.2.5.1 Reading vertex coordinates to create vertex array
2.2.5.2 Point merging
2.2.5.3 Edge merging
2.2.5.4 Searching for closed surface
2.2.6 Intersection test
2.2.6.1 Surface intersection test
2.2.6.1.1 Processing of two triangles in coplanarity
2.2.6.2 Segment–facet intersection test
2.2.6.2.1 Parameterized representation of space triangle
2.2.6.2.2 Intersection of space triangle and segment
2.2.6.2.3 Comparison of the intersection number of two intersection test method
2.2.7 Intersection loop detection
2.2.8 Division of intersecting surface
2.2.8.1 Dividing intersecting triangles into polygons along intersection line
2.2.8.1.1 Classification of positional relationship between intersecting triangle and intersection chain
2.2.8.1.2 Algorithm for dividing intersecting triangles into polygons along intersection chain
2.2.8.1.3 Triangulation for partitioned polygon
2.2.8.2 Subdivision of intersecting triangle after double partition
2.2.8.2.1 Definition of constrained triangulation
2.2.8.2.2 Triangulation of intersecting triangles constrained by intersection chain
2.2.8.3 Division of intersecting triangle strip and intersecting surface
2.2.8.3.1 Division of intersecting triangle strip
2.2.8.3.2 Classification of nonintersecting triangular facets
2.2.9 Positional relationship test
2.2.9.1 STereo Lithography properties of STereo Lithography model slice contour ring
2.2.9.2 Contour ring grouping algorithm based on counter relation
2.2.9.3 Determination of inclusion relation among point and contour ring
2.2.9.3.1 Parametric representation of two straight lines intersection in a plane
2.2.9.3.2 Selection of rays
2.2.9.3.3 Point test in polygon
2.2.10 Program interface and computation example
2.2.11 STereo Lithography primary exploration of Boolean operation application in STereo Lithography model
2.2.12 Summary
2.3 Research on optimization method of intersection test
2.3.1 Space decomposition
2.3.1.1 Cell division
2.3.1.2 Calculation of cell intersecting with triangular facet
2.3.1.3 Searching for all possible intersecting triangles
2.3.1.4 An example of space decomposition optimization
2.3.2 Hierarchical bounding volume trees
2.3.2.1 Overview of bounding box and hierarchical bounding volume tree
2.3.2.2 Construction of AABB hierarchical binary tree
2.3.2.3 Traversing AABB hierarchical binary tree
2.3.3 Summary
2.4 Mesh supporting generation algorithm based on recurrence picking-up and mark method
2.4.1 Support generation algorithm
2.4.2 Rapid recurrence picking-up of support area
2.4.2.1 Concept of pick-up
2.4.2.2 Fast recurrence picking-up
2.4.2.3 Recurrence picking up application
2.4.3 Identification algorithm of supporting segment
2.4.3.1 Traditional algorithm of supporting segment
2.4.3.2 Optimized algorithm of supporting segment
2.4.3.3 Performance comparison and analysis of supporting segment computation
2.4.4 Generation of mesh support
2.4.4.1 Proposal of mesh support
2.4.4.2 Structural design of mesh support
2.4.4.3 Layer scanning of mesh support
2.4.4.4 Software implementation of mesh support
2.4.5 Analysis and comparison for support technics experiment
2.4.5.1 Analysis and comparison for support technics experiment
2.4.5.2 Performance comparison of support generation
2.4.6 Summary
2.5 Data processing of 3D printing galvanometer scanning system
2.5.1 Connection optimization based on tangential arc transition
2.5.2 Fast correction algorithm for dual galvanometers based on fθ lens
2.5.3 Delay processing for scanning data
2.5.4 Dual-thread scanning data transfer processing
2.5.5 Summary
Reference
Further reading
Chapter-3---Research-on-preparation-and-formin_2021_Selective-Laser-Sinterin
3 Research on preparation and forming technologies of selective laser sintering polymer materials
3.1 Overview of selective laser sintering polymer materials
3.1.1 Selective laser sintering forming of polymer materials and research progress
3.1.1.1 Amorphous polymer materials
3.1.1.1.1 Polycarbonate
3.1.1.1.2 Polystyrene
3.1.1.1.3 High impact polystyrene
3.1.1.1.4 Poly(methyl methacrylate)
3.1.1.2 Crystalline polymer materials
3.1.1.2.1 Nylon (polyamide)
3.1.1.2.2 Nylon composite powder materials
3.1.1.2.3 Other crystalline polymer materials
3.2 Preparation method of selective laser sintering materials
3.2.1 Mechanical mixing method
3.2.2 Cryogenic grinding method
3.2.2.1 Cryogenic grinding principle
3.2.2.2 Cryogenic grinding method
3.2.3 Dissolution precipitation method
3.2.3.1 Preparation principle of dissolution precipitation method
3.2.3.2 Preparation of nylon and composite powder materials thereof in dissolution precipitation method
3.2.4 Other preparation methods
3.3 Preparation and forming technology of polymer materials
3.3.1 Preparation of nylon powder and selective laser sintering technology
3.3.1.1 Preparation of nylon 12 powder in dissolution precipitation method
3.3.1.1.1 Preparation experiment of nylon powder
3.3.1.1.2 Preparation technology of nylon powder
3.3.1.1.3 Thermooxidative aging and antiaging of nylon powder
3.3.1.2 Preparation of PA1010 powder in low-temperature grinding method
3.3.1.2.1 Research on grinding experiment
3.3.1.2.2 Experimental results
3.3.1.3 Selective laser sintering technology of nylon 12 and performance of parts
3.3.1.3.1 Melting and crystallization characteristics of nylon 12
3.3.1.3.2 Powder paving performance
3.3.1.3.3 Laser sintering properties
3.3.1.3.4 Mechanical properties
3.3.2 Selective laser sintering technology and posttreatment of polystyrene
3.3.2.1 Preparation of polystyrene and high impact polystyrene prototype models
3.3.2.2 Research on reinforced resin subjected to posttreatment
3.3.2.3 Enhance the performance of the parts
3.3.3 Selective laser sintering of polycarbonate and performance of parts
3.3.3.1 Effect of selective laser sintering technology on performance of polycarbonate sintered parts
3.3.3.1.1 Effect of laser power on section morphology of polycarbonate sintered parts
3.3.3.1.2 Effect of laser power on density and mechanical properties of polycarbonate sintered parts
3.3.3.2 Effect of posttreatment on the properties of polycarbonate sintered parts
3.3.3.2.1 Posttreatment of polycarbonate sintered parts
3.3.3.3 Effect of posttreatment on density and mechanical properties of polycarbonate sintered parts
3.3.3.4 Effect of posttreatment on dimensional accuracy of sintered parts
3.4 Preparation and forming technology of polymer composites
3.4.1 Preparation of carbon fiber/nylon composite powder and selective laser sintering forming technology
3.4.1.1 Selection of raw materials
3.4.1.1.1 Selection of carbon fiber powder
3.4.1.1.2 Selection of nylon
3.4.1.1.3 Selection and dosage of other powder additives
3.4.1.2 Surface treatment of fiber powder
3.4.1.3 Preparation process of composite powder
3.4.1.3.1 Main instruments and property indexes
3.4.1.3.2 Process for preparing composite powder in dissolution precipitation method
3.4.1.3.3 Comparison of dissolution precipitation method and mechanical mixing method
3.4.1.4 Characterization of composite powder
3.4.1.4.1 Test apparatus and test method
3.4.1.4.2 Results and discussions
3.4.1.5 Research on selective laser sintering forming technology of nylon/carbon fiber composite powder
3.4.1.6 Research on the powder paving performance of carbon fiber/nylon 12 composite powder
3.4.1.7 Analysis of the effect of selective laser sintering technological parameters on the properties of sintered parts
3.4.1.8 Research on mechanical properties of sintered parts
3.4.1.8.1 Test apparatus and method
3.4.1.8.2 Results and discussions
3.4.1.9 Observation of section morphology of sintered parts
3.4.1.9.1 Test apparatus and method
3.4.1.9.2 Results and discussions
3.4.1.10 Preparation of rectorite/nylon composite powder and selective laser sintering forming technology
3.4.1.10.1 Overview
3.4.1.10.2 Polymer/layered silicate nanocomposites
3.4.1.10.3 Rectorite
3.4.1.11 Preparation of nylon 12/rectorite composite sintered materials
3.4.1.11.1 Preparation of organic rectorite
3.4.1.11.2 Preparation of composite powder sintered materials
3.4.1.12 Selective laser sintering technology of nylon/rectorite
3.4.1.13 Structural characterization of selective laser sintering nylon 12/rectorite composites
3.4.1.14 Properties of sintered parts of nylon 12/rectorite composites
3.4.1.15 Selective laser sintering intercalation mechanism
3.4.1.16 Example of sintered parts
3.4.2 Preparation of potassium titanate whisker/nylon composite powder and selective laser sintering forming technology
3.4.2.1 Preparation of powder
3.4.2.1.1 Characteristics of powder
3.4.2.1.2 Thermal stability
3.4.2.2 Laser sintering property of powder
3.4.2.2.1 Powder paving property
3.4.2.2.2 Crystallization property
3.4.2.2.3 Selective laser sintering forming property
3.4.2.3 Mechanical properties
3.4.2.4 Analysis of morphology of impact section
3.4.2.5 Selective laser sintering technology and part properties of inorganic filler/nylon composite powder
3.4.2.6 Effect of fillers on selective laser sintering technology
3.4.2.6.1 Effect on powder paving property
3.4.2.6.2 Effect on preheating temperature
3.4.2.6.3 Effect on laser power
3.4.2.7 Effect of fillers on the density and morphology of sintered parts
3.4.2.7.1 Effect of fillers on the density of sintered parts
3.4.2.7.2 Microscopic morphologies of sintered parts
3.4.2.8 Effect of fillers on the properties of sintered parts
3.4.2.8.1 Effect of fillers on the mechanical properties of sintered parts
3.4.2.8.2 Effect of fillers on thermal property of sintered parts
3.4.2.9 Effect of fillers on the thermal oxygen stability of sintered materials
3.4.2.9.1 Effect on colors
3.4.2.9.2 Effect on mechanical properties
3.4.2.10 Example of sintered parts
3.4.3 Preparation of nano-SiO2/nylon composite and selective laser sintering technology
3.4.3.1 Preparation of nanosilica/nylon 12 composite powder
3.4.3.1.1 Main raw materials and apparatus
3.4.3.1.2 Surface modification of nanosilica
3.4.3.1.3 Preparation process of powder
3.4.3.2 Interfacial bonding between nanosilica and nylon 12
3.4.3.3 Characteristic analysis of powder
3.4.3.4 Effect of nanosilica on melting and crystallization behaviors of nylon 12
3.4.3.5 Effect of nanosilica on the thermal stability of nylon 12
3.4.3.6 Dispersion of nanosilica in nylon matrix
3.4.3.7 Effect of nanosilica on the mechanical properties of nylon 12 selective laser sintering forming parts
3.4.3.8 Microscopic morphologies of impact sections of selective laser sintering forming parts
3.4.4 Preparation of nylon-coated aluminum composite and research on selective laser sintering technology
3.4.4.1 Preparation of composite powder
3.4.4.1.1 Selection of raw materials
3.4.4.1.2 Preparation process of nylon 12–coated aluminum composite powder
3.4.4.1.3 Main equipment
3.4.4.1.4 Preparation principle and process
3.4.4.2 Characterization of powder materials
3.4.4.2.1 Particle size and particle size distribution
3.4.4.2.2 Microscopic morphology of powder
3.4.4.2.3 Energy spectrum analysis of powder
3.4.4.2.4 Analysis of thermal weight loss of powder
3.4.4.2.5 Differential scanning calorimetry analysis of powder
3.4.4.3 Selective laser sintering research on selective laser sintering technology of nylon/aluminum composites
3.4.4.3.1 Powder paving properties
3.4.4.3.2 Control of preheating temperature
3.4.4.3.3 Control of scanning spacing
3.4.4.3.4 Optimization experiment of processing parameters
3.4.4.4 Example of sintered parts
3.4.4.5 Effect of aluminum powder content on the properties of selective laser sintering forming parts
3.4.4.5.1 Effect of aluminum powder content on mechanical properties of selective laser sintering forming parts
3.4.4.5.2 Effect of aluminum powder content on dimensional accuracy of selective laser sintering forming parts
3.4.4.6 Dispersion status of aluminum powder particles and interfacial bonding between aluminum powder particles and nylon 12
3.4.4.7 Effect of particle size of aluminum powder on the properties of selective laser sintering forming parts
3.4.4.7.1 Experimental materials
3.4.4.7.2 Experimental content
3.4.4.7.3 Results and discussions
3.4.5 Preparation, forming and posttreatment of nylon-coated spherical carbon steel for selective laser sintering by indire...
3.4.5.1 Preparation and characterization of nylon 12–coated metal powder
3.4.5.1.1 Main raw materials and apparatus
3.4.5.1.2 Preparation process of powder
3.4.5.1.3 Characterization of powder materials
3.4.5.2 Selective laser sintering forming
3.4.5.2.1 Control of preheating temperature
3.4.5.2.2 Effect of laser energy density on bending strength of forming parts
3.4.5.2.3 Analysis of microscopic morphology of fracture surface of bending sample
3.4.5.3 Selective laser sintering example of green parts
3.4.5.4 Degreasing
3.4.5.5 Epoxy resin with low-temperature impregnation and high temperature resistance
3.4.5.5.1 Preparation of epoxy impregnating resin
3.4.5.5.2 Selection of raw materials
3.4.5.6 Impregnation technology of epoxy resin
3.4.5.6.1 Determination of impregnation temperature
3.4.5.7 Properties of green parts impregnated with resin
3.4.5.7.1 Mechanical properties
3.4.5.7.2 Dimensional accuracy
3.4.5.7.3 Microscopic morphology of section
3.4.5.8 Green parts impregnated with resin
3.4.6 Preparation of nylon-coated Cu composite powder and selective laser sintering forming technology
3.4.6.1 Preparation of nylon/copper composite powder materials
3.4.6.1.1 Determination of nylon matrix
3.4.6.1.2 Mechanical mixing preparation method for nylon/Cu composite powder
3.4.6.1.3 Comparison of composite powder obtained in different preparation methods
3.4.6.2 Characterization of nylon/Cu composites
3.4.6.3 Laser sintering properties of nylon 12/Cu-coated composite powder
3.4.6.3.1 Thermal degradation properties of nylon 12/copper powder–coated composite powder
3.4.6.3.2 Melting properties of nylon/copper-coated composite powder
3.4.6.4 Selective laser sintering technology of nylon/copper mechanical composite powder
3.4.6.4.1 Preheating temperature
3.4.6.4.2 Laser power
3.4.6.4.3 Scanning speed
3.4.6.4.4 Thickness of sintering layer
3.4.6.5 Microstructure analysis of sintered parts of nylon/Cu mechanically mixed composite powder
3.4.6.5.1 Laser power
3.4.6.5.2 Scanning speed
3.4.6.5.3 Thickness of sintering layer
3.4.6.6 Laser sintering technology of nylon 12/copper-coated composite powder and properties of parts thereof
3.4.6.6.1 Laser sintering technology of nylon/copper-coated composite powder material
3.4.6.6.2 Accuracy of nylon 12/copper selective laser sintering parts
3.4.6.7 Posttreatment of injection mold green parts formed by nylon/copper composite powder
3.4.6.7.1 Method for cleaning powder for green parts
3.4.6.7.2 Surface treatment of green parts
3.4.6.8 Precision and mechanical properties of nylon/Cu sintered parts upon impregnation
3.4.6.8.1 Accuracy and mechanical properties of green parts impregnated by E-42/tetrahydrophthalic anhydride system
3.4.6.8.2 Accuracy and mechanical properties of green parts impregnated by CYD-128/tetrahydrophthalic anhydride system
3.4.6.8.3 Accuracy and mechanical properties of green parts impregnated by CYD-128/MNA/DMP-30 system
3.4.6.9 Examples of sintered parts
Further reading
Chapter-4---Research-on-preparation-and-forming_2021_Selective-Laser-Sinteri
4 Research on preparation and forming technology of selective laser sintering inorganic nonmetallic materials
4.1 Selective laser sintering forming and research progress of inorganic nonmetallic materials
4.1.1 Slurry-based selective laser sintering technology
4.1.2 Powder-based selective laser sintering technology
4.1.3 Research status of selective laser sintering/cold isostatic pressing/furnace sintering composite forming technology
4.1.4 Selective laser sintering forming and research progress of cast precoated sand
4.2 Selective laser sintering forming and posttreatment technology of ceramic/binder composites
4.2.1 Preparation and forming of nanozirconia–polymer composite powder
4.2.1.1 Overview
4.2.1.2 Powder preparation
4.2.1.2.1 Main raw materials
4.2.1.2.2 Preparation process of powder
Preparation method for stearic acid–nanozirconia composite powder
Preparation of nylon 12–nanozirconia composite powder in solvent precipitation method
Preparation of epoxy resin–granulated zirconia composite powder in mechanical mixing method
4.2.1.2.3 Characterization of powder materials
4.2.1.2.4 Interfacial bonding of nanozirconia and polymers
4.2.1.3 Analysis on laser sintering forming technology of polymer/ceramic composite powder
4.2.1.3.1 Polymer/ceramic mechanically mixed powder
The mechanically mixed powder absorbs laser energy
Wetting of binders on ceramic particles
Sintering between polymer binder particles
4.2.1.3.2 Polymer-coated ceramic powder
The coated powder absorbs laser energy
Sintering of the binder layer
4.2.1.3.3 Difference between coated powder and mechanically mixed powder in laser sintering
4.2.1.4 Forming technology
4.2.1.4.1 Selective laser sintering forming parameters
Control to preheating temperature
Experimental design
4.2.1.4.2 Cold isostatic pressing
4.2.1.4.3 Thermal debinding
Thermal debinding technology in which epoxy resin E06 is used as the binder
The binder is treated based on the thermal debinding technology of stearic acid
The binder is treated based on the thermal debinding technology of nylon 12
4.2.1.4.4 Furnace sintering
4.2.1.5 Analysis of results
4.2.1.5.1 Shrinkage
Effect of laser energy density on selective laser sintering shrinkage
Effect of laser energy density on cold isostatic pressing shrinkage
Effect of laser energy density on furnace sintering shrinkage
4.2.1.5.2 Relative density
4.2.1.5.3 Microscopic morphology
Microscopic morphology of EZ10 sample
Microscopic morphology of SZ20 sample
Microscopic morphology of PZ20 sample
4.2.1.5.4 X-ray diffraction phase analysis
4.2.1.5.5 Micro-Vickers hardness
4.2.1.5.6 Manufacturing of typical complex parts
4.2.2 Research on forming mechanism and technology of selective laser sintering/cold isostatic pressing/furnace sintering a...
4.2.2.1 Overview
4.2.2.2 Preparation and characterization of powder materials
4.2.2.2.1 Selection of alumina powder and binders
Selection of alumina powder
Selection of binders
Characteristic analysis of epoxy resin
4.2.2.2.2 Preparation and characterization of Al2O3–epoxy resin E06 composite powder
Preparation and characterization of powder
Determination of binder content
4.2.2.3 Research on forming mechanism and technology of alumina green parts in selective laser sintering process
4.2.2.3.1 Forming mechanism of alumina green parts in selective laser sintering process
4.2.2.3.2 Forming technology of alumina green parts in selective laser sintering process
4.2.2.4 Research on the densification mechanism and technology of alumina in cold isostatic pressing process
4.2.2.4.1 Densification mechanism of alumina sample in cold isostatic pressing process
4.2.2.4.2 Densification technology of alumina sample in cold isostatic pressing process
4.2.2.5 Research on the densification mechanism and technology of alumina in degreasing process
4.2.2.5.1 Densification mechanism of degreased alumina forming parts
4.2.2.5.2 Densification technology of degreased alumina forming parts
4.2.2.6 Research on the densification mechanism and technology of alumina in furnace sintering process
4.2.2.6.1 Densification mechanism of alumina sample in furnace sintering
Driving force
Densification way
4.2.2.6.2 Densification technology of alumina sample in furnace sintering
4.2.3 Research on selective laser sintering/cold isostatic pressing/furnace sintering composite forming technology of carcl...
4.2.3.1 Overview
4.2.3.2 Experimental process
4.2.3.2.1 Powder preparation
4.2.3.2.2 Selective laser sintering/cold isostatic pressing forming
4.2.3.2.3 Degreasing and glazing
4.2.3.2.4 Furnace sintering
4.2.3.3 Results and discussions
4.2.3.3.1 Shrinkage
Technological process
Laser energy density
Furnace sintering temperature
4.2.3.3.2 Density
Technological process
Laser energy density
Furnace sintering temperature
4.2.3.3.3 Microscopic morphology
Microscopic morphology of sample in selective laser sintering/cold isostatic pressing process
Effect of sintering temperature on scanning electron microscopic morphology of carclaxyta
4.2.3.3.4 X-ray diffraction
4.2.3.3.5 Microhardness
4.2.3.4 Manufacturing of typical ceramic products
4.2.4 Research on selective laser sintering forming and posttreatment of silicon carbide ceramics
4.2.4.1 Research on laser sintering of silicon carbide ceramic preformed green parts
4.2.4.1.1 Principle and characteristics of indirect selective laser sintering of silicon carbide
4.2.4.1.2 Effect of properties of sintered powder on laser sintering forming
Effect of apparent density of silicon carbide powder on laser sintering forming
Determination of the types and content of bonding materials
4.2.4.1.3 Determination of technological parameters of indirect selective laser sintering forming of ceramics
Preheating temperature
Effect of laser power and scanning speed on selective laser sintering forming
4.2.4.1.4 Measures to improve the sintering quality of the prototype parts
4.2.4.2 Research on posttreatment of parts
4.2.4.2.1 Powder cleaning method for preformed green parts
4.2.4.2.2 Research on degreasing and degradation technologies of green parts
Thermal degreasing mechanism
Research on protective atmosphere and vacuum thermal degreasing degradation
Research on oxidative degreasing under air atmosphere
4.2.4.2.3 Furnace sintering
Research on parameters of furnace sintering technology
Research on accuracy control during furnace sintering
4.2.4.3 Research on infiltration of silicon carbide ceramic parts
4.2.4.3.1 Research on infiltrated resin
Infiltration theory of porous media
Infiltration technology
4.2.4.3.2 Research on infiltrated metal
Infiltration technology
Effect of the SiO2 film generated through preoxidation on oxidative infiltration
Effect of magnesium on oxidative infiltration
Microscopic structure and fracture morphology
4.3 Selective laser sintering sintering mechanism and forming technology of precoated sand
4.3.1 Research on selective laser sintering laser sintering mechanism and characteristics of precoated sand
4.3.1.1 Overview of laser sintering of precoated sand
4.3.1.2 Experiment
4.3.1.3 Laser heating temperature model
4.3.1.4 Curing mechanism of precoated sand
4.3.1.5 Curing kinetics of precoated sand
4.3.1.6 Analysis on laser sintering curing characteristics of precoated sand
4.3.1.6.1 Infrared analysis of laser-sintered precoated sand
4.3.1.6.2 DSC analysis of laser-sintered precoated sand
4.3.1.6.3 Thermogravimetric analysis of laser-sintered precoated sand
4.3.1.7 Laser sintering characteristics of precoated sand
4.3.1.7.1 Heterogeneity of temperature and curing degree
4.3.1.7.2 High-temperature transient properties
4.3.1.7.3 Effect of curing on preheating temperature
4.3.1.7.4 Gas overflow
4.3.1.7.5 Friction between sands
4.3.1.7.6 Effect of laser sintering characteristics of precoated sand on accuracy
4.3.2 Research on selective laser sintering sintering technology and properties of precoated sand
4.3.2.1 Analysis on failure to laser sintering forming of precoated sand
4.3.2.2 Effect of properties of precoated sand on laser sintering properties
4.3.2.2.1 Resin content
4.3.2.2.2 Particle size of sand
4.3.2.2.3 Effect of geometrical morphology of roughing sand on properties of selective laser sintering sample
4.3.2.2.4 Melting point of resin
4.3.2.3 Selective laser sintering forming technology of precoated sand
4.3.2.3.1 Relationship between selective laser sintering forming technology and strength of selective laser sintering sample
4.3.2.3.2 Curing and warpage
4.3.2.3.3 Curing depth and sand bonding depth
4.3.2.3.4 Energy superposition
4.3.2.3.5 Strength of laser-sintered-coated sand molds (cores) with equal energy density
4.3.2.4 Postcuring of selective laser sintering precoated sand molds (cores)
4.3.2.5 Amount of gas evolution and gas permeability
Further reading
Chapter-5---Selective-laser-sinterin_2021_Selective-Laser-Sintering-Additive
5 Selective laser sintering forming accuracy control
5.1 Dimensional accuracy
5.1.1 Plane error
5.1.1.1 Equipment error
5.1.1.2 CAD model error
5.1.1.3 Fabrication error
5.1.1.3.1 Error caused by shrinkage
5.1.1.3.2 Error caused by slicing
5.1.2 Height error
5.1.2.1 Equipment error
5.1.2.2 CAD model error
5.1.2.3 Fabrication error
5.1.2.3.1 Error caused by single-layer thickness of powder sintering
5.1.2.3.2 Height error caused by warping
5.1.2.3.3 Height error caused by shrinkage
5.1.2.3.4 Height error caused by movement of powder downward
5.1.2.3.5 Error caused by slicing
5.2 Shape accuracy
5.2.1 One-dimensional warpage
5.2.1.1 Two-layer sintering
5.2.1.2 Sintering shrinkage warping model of three or more layers
5.2.2 Two-dimensional warpage
5.2.3 Squaring of circles
5.3 Forming shrinkage
5.3.1 Composition of forming shrinkage
5.3.2 Calculation model of forming shrinkage
5.3.2.1 Temperature–induced shrinkage
5.3.2.2 Sintering shrinkage
5.3.2.3 Crystallization shrinkage
5.3.3 Measures to reduce shrinkage
5.4 Secondary sintering
5.4.1 Reasons for secondary sintering
5.4.2 Experimental test
5.4.2.1 Materials
5.4.2.2 Selective laser sintering forming
5.4.2.3 Measurement of dimensional accuracy
5.4.2.4 Measurement of relative density
5.4.3 Results and analysis
5.4.3.1 Effects of preheating temperature on secondary sintering
5.4.3.2 Effects of laser energy density on secondary sintering
5.4.3.3 Effects of inorganic filler on secondary sintering
5.4.3.4 Effects of fusion heat on secondary sintering
5.4.4 Conclusions
5.5 Bonus Z
5.5.1 Reasons for bonus Z
5.5.2 Experimental test
5.5.2.1 Materials
5.5.2.2 Selective laser sintering forming
5.5.2.3 Dimensional accuracy measurement
5.5.3 Results and analysis
5.5.3.1 Effects of laser energy density on bonus Z
5.5.3.2 Effects of slice thickness on bonus Z
5.5.3.3 Effects of preheating temperature on secondary sintering
5.5.4 Conclusions
5.6 Displacement of sintered parts during powder laying
5.6.1 Displacement of sintered parts during powder laying and its influence on the sintering process
5.6.2 Reasons for displacement of sintered parts during powder laying
5.6.3 Characterization and experimental study of sintered parts displacement during powder laying
Further reading
Chapter-6---Numerical-analysis-of-selec_2021_Selective-Laser-Sintering-Addit
6 Numerical analysis of selective laser sintering key technology
6.1 Numerical simulation of preheating temperature field
6.1.1 Heat transfer analysis of selective laser sintering preheating temperature field
6.1.2 Modeling and solving radiation heating
6.1.2.1 Radiation heating modeling
6.1.2.2 Radiation heating model solving
6.1.3 Numerical calculation and result analysis
6.1.3.1 Uniformity evaluation of temperature field
6.1.3.2 Maximum deviation evaluation of temperature measuring point
6.1.4 Improvement measures
6.1.5 Summary
6.2 Numerical simulation of selective laser sintering forming densification process
6.2.1 Study on material model of densification process of selective laser sintering forming part
6.2.1.1 Deformation characteristics of porous material
6.2.1.2 Modified Cam-Clay model
6.2.1.3 Drucker–Prager–Cap model
6.2.1.4 Introduction to nonlinear finite element development and ABAQUS software
6.2.1.5 Summary
6.2.2 Selective laser sintering densification process simulation based on Cam-Clay model
6.2.2.1 Material and experiment
6.2.2.2 Fundamental equations for porous materials elastoplastic mechanical problem
6.2.2.3 Cold isostatic pressing experiment simulation
6.2.2.4 Cold isostatic pressing simulation of selective laser sintering part
6.2.2.5 Study on sensitivity of simulation result to model parameter
6.2.2.6 Summary
6.2.3 Selective laser sintering densification process simulation based on Drucker–Prager–Cap model
6.2.3.1 Analysis of models with contact relation
6.2.3.2 Cold isostatic pressing process simulation of uncapsuled cylindrical part
6.2.3.3 Cold isostatic pressing process simulation of capsuled cylindrical part
6.2.3.4 Effect of friction coefficient between parts and capsules
6.2.3.5 Study on sensitivity of simulation results to model parameters
6.2.3.6 Summary
6.2.4 Examples of cold isostatic pressing process numerical simulation for selective laser sintering indirect forming metal...
6.2.4.1 Cold isostatic pressing simulation of gear part
6.2.4.2 Cold isostatic pressing simulation of axisymmetric parts
6.2.4.3 Design of initial part size
6.2.4.4 Summary
6.2.5 Examples of hot isostatic pressing process numerical simulation for selective laser sintering indirect forming metal part
6.2.5.1 Selective laser sintering/hot isostatic pressing process
6.2.5.2 Selective laser sintering/hot isostatic pressing experiment
6.2.5.3 Finite element method and creep subroutine with the temperature considered
6.2.5.3.1 Finite element method with the temperature considered
6.2.5.3.2 Creep subroutine
6.2.5.4 Hot isostatic pressing simulation of selective laser sintering part
6.2.5.5 Summary
6.3 Study on numerical simulation of densification process of selective laser sintering forming ceramic part
6.3.1 Numerical simulation technology route of SLS/CIP/FS composite forming of alumina ceramic parts
6.3.2 Study on numerical simulation of cold isostatic pressing densification of alumina ceramic selective laser sintering part
6.3.2.1 Cold isostatic pressing pressure–volume plastic strain relationship of alumina selective laser sintering parts
6.3.2.2 Modified Cam-Clay model for simulating the cold isostatic pressing process of selective laser sintering parts
6.3.2.2.1 Visual analysis of cold isostatic pressing densification process
6.3.2.2.2 Size error analysis of numerical simulation
6.3.2.2.3 Densification behavior of Al2O3 laser sintered parts during cold isostatic pressing
6.3.2.3 Modified Drucker–Prager/Cap model for simulating the cold isostatic pressing process of laser sintered parts
6.3.2.3.1 Material and model parameter
6.3.2.3.2 Cold isostatic pressing simulation and experimental verification of capsuled cuboid part
6.3.3 Study on numerical simulation of high-temperature sintering densification of alumina ceramic SLS/CIP parts
6.3.3.1 Study on sintering experiment and simulation of Al2O3 cold isostatic pressing sample in thermal dilatometer
6.3.3.2 Numerical simulation of solid phase sintering of Al2O3 cold isostatic pressing part
6.3.4 Summary
Further reading
Chapter-7---Typical-applications-of-sel_2021_Selective-Laser-Sintering-Addit
7 Typical applications of selective laser sintering technology
7.1 Applications of selective laser sintering in sand casting
7.1.1 Manufacturing of complex hydraulic pressure valve body
7.1.1.1 Structure analysis of hydraulic valve body
7.1.1.2 Selection of casting method for hydraulic valve
7.1.1.3 Preparation of sand molds (cores)
7.1.1.4 Postcuring
7.1.1.5 Casting process of hydraulic valve body
7.1.2 Manufacturing of cylinder head
7.1.3 Selective laser sintering forming of other sand molds (cores)
7.2 Application of selective laser sintering in investment casting
7.2.1 Selection for selective laser sintering patterns
7.2.2 Posttreatment of wax infiltration for selective laser sintering prototype
7.2.3 Thermal performance of selective laser sintering molds
7.2.3.1 Selective laser sintering pattern melting and melt viscous flow performance
7.2.3.2 Relationship between melt viscosity and temperature of selective laser sintering pattern
7.2.4 Thermal weight loss (thermogravimetric) analysis of selective laser sintering pattern
7.2.5 Measurement of ash content of selective laser sintering mold decomposed in air
7.3 Study on dewaxing process
7.4 Production experiment
7.5 Application of selective laser sintering in manufacturing injection mold with conformal cooling channel
7.5.1 Conformal cooling technology
7.5.1.1 Necessity of conformal cooling technology
7.5.1.2 Realization of conformal cooling channel
7.5.2 Selective laser sintering forming of parts
7.5.3 Posttreatment of parts
7.5.3.1 Clearing powder
7.5.3.2 Densification
7.5.4 Injection molding of part
7.5.5 Application of selective laser sintering in manufacturing ceramic part
7.6 Application of selective laser sintering in manufacturing plastic functional part
7.6.1 Manufacture of plastic functional parts by selective laser sintering indirect method
7.6.1.1 Preparation of prototype
7.6.1.1.1 PS and HIPS prototype
7.6.1.1.2 PC prototype
7.6.1.2 Research on reinforced resin subjected to posttreatment
7.6.2 Infiltration and permeation
7.6.2.1 Curing rate and posttreatment reinforcement technology
7.6.2.2 Performance of the reinforced part
7.6.3 Direct manufacturing of plastic functional part by selective laser sintering
Further reading
Index_2021_Selective-Laser-Sintering-Additive-Manufacturing-Technology
Index