Principles of Laser Materials Processing: Developments and Applications

✍ Scribed by Elijah Kannatey-Asibu Jr.

• Publisher: Wiley
• Year: 2023
• Tongue: English
• Leaves: 611
• Edition: 2
• Category: Library

✦ Synopsis

Principles of Laser Materials Processing

Authoritative resource providing state-of-the-art coverage in the field of laser materials processing, supported with supplementary learning materials

Principles of Laser Materials Processing goes over the most recent advancements and applications in laser materials processing, with the second edition providing a welcome update to the successful first edition through updated content on the important fields within laser materials processing. The text includes solved example problems and problem sets suitable for the readers’ further understanding of the technology explained.

Split into three parts, the text first introduces basic concepts of lasers, including the characteristics of lasers and the design of their components, to aid readers in their initial understanding of the technology. The text then reviews the engineering concepts that are needed to analyze the different processes. Finally, it delves into the background of laser materials and provides a state-of-the-art compilation of material in the major application areas, such as laser cutting and drilling, welding, surface modification, and forming, among many others. It also presents information on laser safety to prepare the reader for working in the industry sector and provide practicing engineers the updates needed to work safely and effectively.

In Principles of Laser Materials Processing, readers can expect to find specific information on:

• Laser generation principles, including basic atomic structure, atomic transitions, population distribution, absorption, and spontaneous emission
• Optical resonators, including standing waves in a rectangular cavity, planar resonators, beam modes, line selection, confocal resonators, and concentric resonators
• Laser pumping, including optical pumping, arc/flash lamp pumping, energy distribution in the active medium, and electrical pumping
• Broadening mechanisms, including line-shape functions, homogeneous broadening such as natural and collision, and inhomogeneous broadening

Principles of Laser Materials Processing is highly suitable for senior undergraduate and graduate students studying laser processing, and non-traditional manufacturing processes; it is also aimed at researchers to provide additional information to be used in research projects that are to be undertaken within the technology field.

✦ Table of Contents

Cover
Title Page
Copyright
Contents
PREFACE TO THE SECOND EDITION
PREFACE TO THE FIRST EDITION
ABOUT THE COMPANION WEBSITE
Part I Principles of Industrial Lasers
Chapter 1 Laser Background
1.1 Laser Generation
1.1.1 Atomic Transitions
1.1.2 Lifetime
1.1.3 Optical Absorption
1.1.4 Population Inversion
1.1.5 Threshold Gain
1.1.6 Two‐Photon Absorption
1.2 Optical Resonators
1.2.1 Standing Waves In A Rectangular Cavity
1.2.2 Planar Resonators
1.2.3 Confocal Resonators
1.2.4 Concentric Resonators
1.3 Laser Pumping
1.3.1 Optical Pumping
1.3.2 Electrical Pumping
1.4 System Levels
1.4.1 Two‐Level System
1.4.2 Three‐Level System
1.5 Broadening Mechanisms
1.5.1 Line Shape Function
1.5.2 Line‐Broadening Mechanisms
1.5.3 Comparison of Individual Mechanisms
1.6 Beam Modification
1.6.1 Quality Factor
1.6.2 Q‐Switching
1.6.3 Mode Locking
1.7 Beam Characteristics
1.7.1 Beam Divergence
1.7.2 Monochromaticity
1.7.3 Beam Coherence
1.7.4 Intensity and Brightness
1.7.5 Focusing
1.8 Summary
1.8 Problems
1.8 Bibliography
Chapter 2 Types of Lasers
2.1 SOLID‐STATE LASERS
2.1.1 The Nd:YAG Laser
2.1.2 The Nd:Glass Laser
2.2 GAS LASERS
2.2.1 Neutral Atom Lasers
2.2.2 Ion Lasers
2.2.3 Molecular Gas Lasers
2.3 SEMICONDUCTOR (DIODE) LASERS
2.3.1 Semiconductor Background
2.3.2 Semiconductor Lasers
2.3.3 Semiconductor Laser Types
2.3.4 Low‐Power Diode Lasers
2.3.5 High‐Power Diode Lasers
2.3.6 Applications of High‐Power Diode Lasers
2.4 NEW DEVELOPMENTS IN INDUSTRIAL LASER TECHNOLOGY
2.4.1 Slab Lasers
2.4.2 Disk Lasers
2.4.3 Ultrafast (Femtosecond) Lasers
2.4.4 Fiber Lasers
2.5 SUMMARY
2.5 Problems
2.5 Bibliography
Chapter 3 Beam Delivery
3.1 The Electromagnetic Spectrum
3.2 Birefringence
3.3 Brewster Angle
3.4 Polarization
3.5 Beam Expanders
3.6 Beam Splitters
3.7 Beam Delivery Systems
3.7.1 Conventional Beam Delivery
3.7.2 Fiber Optic Systems
3.8 Beam Shaping
3.8.1 Beam Shaping Using Diffractive Optics
3.8.2 Beam Shaping Using Coherent Beam Combining and Optical Phase Array
3.9 Summary
3.9 PROBLEMS
3.9 Bibliography
Part II Engineering Background
Chapter 4 Heat and Fluid Flow
4.1 Energy Balance During Processing
4.2 HEAT FLOW IN THE WORKPIECE
4.2.1 Temperature Distribution
4.2.2 Peak Temperatures
4.2.3 Cooling Rates
4.2.4 Gaussian Heat Source
4.2.5 The Two‐Temperature Model
4.3 FLUID FLOW IN MOLTEN POOL
4.3.1 Continuity Equation
4.3.2 Navier–Stokes Equations
4.3.3 Surface Tension Effect
4.3.4 Free Surface Modeling
4.4 SUMMARY
4.4 Problems
4.4 BIBLIOGRAPHY
Chapter 5 The Microstructure
5.1 PROCESS MICROSTRUCTURE
5.1.1 Fusion Zone
5.1.2 Zone of Partial Melting
5.1.3 Heat‐Affected Zone
5.2 DISCONTINUITIES
5.2.1 Porosity
5.2.2 Cracking
5.2.3 Lack of Fusion
5.2.4 Incomplete Penetration
5.2.5 Undercut
5.3 SUMMARY
5.3 Problems
5.3 BIBLIOGRAPHY
Chapter 6 Solidification
6.1 SOLIDIFICATION WITHOUT FLOW
6.1.1 Solidification of a Pure Metal
6.1.2 Solidification of a Binary Alloy
6.2 SOLIDIFICATION WITH FLOW
6.2.1 Mushy Fluid
6.2.2 Columnar Dendritic Structure
6.3 RAPID SOLIDIFICATION
6.4 SUMMARY
6.4 Problems
6.4 Bibliography
Chapter 7 Residual Stresses and Distortion
7.1 CAUSES OF RESIDUAL STRESSES
7.1.1 Thermal Stresses
7.1.2 Nonuniform Plastic Deformation
7.2 BASIC STRESS ANALYSIS
7.2.1 Stress–Strain Relations
7.2.2 Plane Stress and Plane Strain
7.2.2 Solution:
7.3 EFFECTS OF RESIDUAL STRESSES
7.3.1 Apparent Change in Strength
7.3.2 Distortion
7.4 MEASUREMENT OF RESIDUAL STRESSES
7.4.1 Stress Relaxation Techniques
7.4.1 Solution:
7.4.2 X‐ray Diffraction Technique
7.4.3 Neutron Diffraction Technique
7.4.4 Residual Stress Equilibrium
7.4.4 Solution:
7.5 RELIEF OF RESIDUAL STRESSES AND DISTORTION
7.5.1 Thermal Treatments
7.5.2 Mechanical Treatments
7.6 SUMMARY
7.6 Problems
7.6 Bibliography
Part III Laser Materials Processing
Chapter 8 Background on Laser Processing
8.1 System‐Related Parameters
8.1.1 Power and Power Density
8.1.2 Wavelength and Focusing
8.1.3 Beam Mode
8.1.4 Beam Form
8.1.5 Beam Quality
8.1.6 Beam Absorption
8.1.7 Beam Alignment
8.1.8 Motion Unit
8.2 Process Efficiency
8.3 Disturbances That Affect Process Quality
8.4 General Advantages and Disadvantages of Laser Processing
8.4.1 Advantages
8.4.2 Disadvantages
8.5 Summary
8.5 Problems
8.5 Bibliography
Chapter 9 Laser Cutting and Drilling
9.1 Laser Cutting
9.1.1 Forms of Laser Cutting
9.1.2 Components of a Laser Cutting System
9.1.3 Processing Conditions
9.1.4 Laser Cutting Principles
9.1.5 Quality of Cut Part
9.1.6 Material Considerations
9.1.7 Advantages and Disadvantages of Laser Cutting
9.1.8 Specific Comparison with Conventional Processes
9.1.9 Special Techniques
9.2 Laser Drilling
9.2.1 Forms of Laser Drilling
9.2.2 Process Parameters
9.2.3 Analysis of Material Removal During Drilling
9.2.4 Advantages and Disadvantages of Laser Drilling
9.2.5 Applications
9.3 New Developments
9.3.1 Micromachining
9.3.2 Laser‐Assisted Machining
9.4 Summary
9.4 Problems
9.4 BIBLIOGRAPHY
Chapter 10 Laser Welding
10.1 Laser Welding Parameters
10.1.1 Beam Power and Traverse Speed
10.1.2 Effect of Beam Characteristics
10.1.3 Plasma Formation, Gas Shielding, and Effect of Ambient Pressure
10.1.4 Beam Size and Focal Point Location
10.1.5 Joint Configuration
10.2 Welding Efficiency
10.3 Mechanism of Laser Welding
10.3.1 Conduction Mode Welding
10.3.2 Keyhole Welding
10.4 Material Considerations
10.4.1 Steels
10.4.2 Nonferrous Alloys
10.4.3 Ceramic Materials
10.4.4 Dissimilar Metals
10.5 Weldment Discontinuities
10.5.1 Porosity
10.5.2 Humping
10.6 Advantages and Disadvantages of Laser Welding
10.6.1 Advantages
10.6.2 Disadvantages
10.7 Special Techniques
10.7.1 Multiple‐Beam Welding
10.7.2 Arc‐Augmented Laser Welding
10.7.3 Wobble Welding
10.7.4 Remote Laser Welding
10.8 Specific Applications
10.8.1 Microwelding
10.8.2 Laser‐Welded Tailored Blanks
10.8.3 Laser Transmission Welding of Plastics
10.8.4 Laser Brazing
10.9 Summary
10.9 Problems
10.9 Bibliography
Chapter 11 Laser Surface Modification
11.1 Laser Surface Heat Treatment
11.1.1 Important Criteria
11.1.2 Key Process Parameters
11.1.3 Temperature Field
11.1.4 Microstructural Changes in Steels
11.1.5 Nonferrous Alloys
11.1.6 Hardness Variation
11.1.7 Residual Stresses
11.1.8 Semiconductors
11.1.9 Polymers
11.1.10 Advantages and Disadvantages of Laser Surface Treatment
11.2 Laser Surface Melting
11.3 Laser Direct Metal Deposition
11.3.1 Processing Parameters
11.3.2 Methods for Depositing the Material
11.3.3 Dilution
11.3.4 Advantages and Disadvantages of Laser Deposition
11.4 Laser Physical Vapor Deposition (LPVD)
11.5 Laser Shock Peening
11.5.1 Background Analysis
11.5.2 Thermal Relaxation at High Temperatures
11.5.3 Advantages and Disadvantages of Laser Shock Peening
11.5.4 Applications
11.6 Laser Texturing
11.7 Summary
11.7 Problems
11.7 BIBLIOGRAPHY
Chapter 12 Laser Forming
12.1 Principle of Laser Forming
12.2 Process Parameters
12.3 Laser‐Forming Mechanisms
12.3.1 Temperature Gradient Mechanism
12.3.2 Buckling Mechanism
12.3.3 Upsetting Mechanism
12.3.4 Summary of the Forming Mechanisms
12.4 Process Analysis
12.5 Advantages and Disadvantages
12.5.1 Advantages
12.5.2 Disadvantages
12.6 Applications
12.7 Summary
12.7 Problems
12.7 Bibliography
Chapter 13 Additive Manufacturing
13.1 Computer‐Aided Design
13.1.1 Curve and Surface Design
13.1.2 Solid Modeling
13.1.3 Software Formats
13.1.4 Supports for Part Building
13.1.5 Slicing
13.2 Part Building
13.2.1 Liquid‐Based Systems
13.2.2 Powder‐Based Systems
13.2.3 Solid‐Based Systems
13.2.4 Qualitative Comparison of Some Major Systems
13.3 Post‐Processing
13.4 Applications
13.4.1 Design
13.4.2 Engineering, Analysis, and Planning
13.4.3 Manufacturing and Tooling
13.4.4 Personalized Production
13.5 Advantages and Disadvantages
13.5.1 Advantages
13.5.2 Disadvantages
13.6 Summary
13.6 Problems
13.6 Bibliography
Chapter 14 Medical and Nanotechnology Applications of Lasers
14.1 Medical Applications
14.1.1 Medical Devices
14.1.2 Therapeutic Applications
14.2 Nanotechnology Applications
14.2.1 Nanoholes and Grating
14.2.2 Nanobumps
14.2.3 Laser‐Assisted Nanoimprint Lithography
14.3 Summary
14.3 Bibliography
Chapter 15 Sensors for Process Monitoring
15.1 Laser Beam Monitoring
15.1.1 Beam Power
15.1.2 Beam Mode
15.1.3 Beam Size
15.2 Process Monitoring
15.2.1 Acoustic Emission (AE)
15.2.2 Acoustic Mirror
15.2.3 Audible Sound (AS) Emission
15.2.4 Infrared/Ultraviolet (IR/UV) Detection Techniques
15.2.5 Optical (Vision) Sensing
15.3 Summary
15.3 Problems
15.3 BIBLIOGRAPHY
Chapter 16 Processing of Sensor Outputs
16.1 SIGNAL TRANSFORMATION
16.1.1 The Fourier Transform
16.1.2 The Discrete Fourier Transform (DFT)
16.1.3 Pitfalls of Digital Analysis
16.1.4 The Sampling Theorem
16.1.5 Aliasing
16.1.6 Leakage
16.2 DATA REDUCTION
16.2.1 Variance Criterion
16.2.2 Fisher Criterion
16.3 PATTERN CLASSIFICATION
16.3.1 Pattern Recognition
16.3.2 Neural Network Analysis
16.3.3 Sensor Fusion
16.3.4 Time–Frequency Analysis
16.3.5 Applications in Manufacturing
16.4 SUMMARY
16.4 Problems
16.4 Bibliography
Chapter 17 Laser Safety
17.1 Laser Hazards
17.1.1 Radiation‐Related Hazards
17.1.2 Nonbeam Hazards
17.2 Laser Classification
17.3 Preventing Laser Accidents
17.3.1 Laser Safety Officer (LSO)
17.3.2 Engineering Controls
17.3.3 Administrative and Procedural Controls
17.3.4 Protective Equipment
17.3.5 Warning Signs and Labels
17.4 Summary
17.4 Problem
17.4 Bibliography
INDEX
EULA