Laser Shock Peening: Fundamentals and Advances

Preface
Contents
1 Characteristics and Development Status of Laser Shock Peening
	1.1 The Concept and Connotation of Laser Shock Peening
	1.2 Characteristics of Laser Shock Peening
	1.3 Early Experimental Study on Laser Shock Peening
		1.3.1 Five Developmental Stages of LSP
		1.3.2 Research and Development of LSP in China
	1.4 Development of Industrial Applications of Laser Shock Peening
		1.4.1 Applications on Aero-Engines
		1.4.2 Application on Aircraft Structure
		1.4.3 Application on Weld Structure
	1.5 New Application Direction of Laser Shock Peening
	References
2 Laser Shock Hardening Industrial Application System
	2.1 Laser in China and Abroad
		2.1.1 Laser Jointly Developed by University of Science and Technology of China and Jiangsu University
		2.1.2 Gaia High-Energy Equivalent Pumped YAG Laser of French THALES
		2.1.3 Laser Scheme with Two-Way Laser Beam Output of Labao Company
		2.1.4 Laser Developed by LSPT Company
		2.1.5 Laser Being Developed by Japanese Company
	2.2 Design Scheme of Laser of AVIC Manufacturing Technology Institute
		2.2.1 Design Scheme of the Local Oscillation Laser
		2.2.2 Design Scheme of Laser Amplifier
		2.2.3 Program Analysis
		2.2.4 Power Supply Based on IGBT Inverter Technology
	2.3 Workbench of the Strengthening System
	2.4 Beam Moving Scanning System Developed by MIC
	References
3 Stability Factors and Safety Protection of Laser Shock Peening
	3.1 Process Stability Factors
		3.1.1 Adjustable Laser Spot and Continuous Laser Path
		3.1.2 Flat Confinement Layer
		3.1.3 The Integrity of the Absorption Layer
		3.1.4 The Quality of the Target Material
	3.2 Research on the Application of Confinement Layer
		3.2.1 Introduction and Application of Water Confinement Layer
		3.2.2 Laser Absorbance in Water and Selection of Restrained Layer Thickness
		3.2.3 Influence of Water-Confined Layer on Shock Wave
		3.2.4 Parasitic Plasma
		3.2.5 Optical Path Purification
	3.3 Status of Damaged Tape and Absorption Layer
		3.3.1 No Absorption Layer
		3.3.2 Slightly Damaged Absorption Layer
		3.3.3 No Damaged Absorption Layer
	3.4 Effect Mechanism of Target
	3.5 Strengthen Effect Improvement and Safety Protection
		3.5.1 Application of Spall Prevention Technology
		3.5.2 Methods to Enhance Strengthening Effect
		3.5.3 Light Reflection and Explosive Fragmentation of Safety Protection
	References
4 Numerical Analysis of Mechanical Effects of Laser Shock Peening
	4.1 Physical Model
		4.1.1 Fabbro Physical Model
		4.1.2 Modified Physical Model
	4.2 Numerical Analysis Steps
		4.2.1 Finite Element Analysis Method
		4.2.2 Numerical Model Parameter Setting
	4.3 Numerical Analysis of Circular Laser Spot
		4.3.1 Finite Element Model
		4.3.2 Dynamic Stress–Strain Analysis of Shock Wave Loading Process
		4.3.3 Study of Residual Stress Field and Surface Plastic Deformation in the Laser Shock Area
		4.3.4 Verification of the Residual Stress Field in the Laser Shock Zone
		4.3.5 Relationship Between Surface Profile and Residual Stresses in the Single-Spot Impact Zone
		4.3.6 Residual Stress Field of Lap-Spot
	4.4 Square Spot Values Analysis
		4.4.1 Finite Element Model
		4.4.2 Shock Wave Loading
		4.4.3 Residual Stress Distribution Under Different Process Parameters
	References
5 Evaluations of the Strengthening Effect of the Metals with Laser Shock Peening
	5.1 Surface Profiles Induced by Square Spots
		5.1.1 Spot Overlapping Patterns
		5.1.2 Surface Profiles Induced by Square Spots
		5.1.3 Path Planning of Spot Overlapping
	5.2 Mechanical Property of High-Temperature Alloy
		5.2.1 Overseas Research Status
		5.2.2 Effect of Thermal Cycles on Residual Stresses of High-Temperature GH2036 Alloy
		5.2.3 Fatigue Lives of High-Temperature GH30 Alloy
		5.2.4 Fatigue Crack Growth Rate of High-Temperature GH30 Alloy
	5.3 Mechanical Property of Stainless Steel
		5.3.1 Fatigue Lives of 1Cr18Ni9Ti Austenitic Stainless Steel
		5.3.2 Fatigue Lives of 1Cr11Ni2W2MoV Stainless Steel
		5.3.3 Plastic Deformations of Almen Samples (SE707 Stainless Steel)
	5.4 Mechanical Property of Titanium Alloys
		5.4.1 Mechanical Property of TC4 Titanium Alloy
		5.4.2 Mechanical Property of TC17 Titanium Alloy
		5.4.3 Mechanical Property of TC21 Titanium Alloy
		5.4.4 Mechanical Property of TA19 Titanium Alloy
	5.5 Mechanical Property of Aluminum Alloys
		5.5.1 Fatigue Lives of 1420 Aluminum–Lithium Alloy
		5.5.2 Fatigue Lives of 7050 Aluminum Alloy Fastening Holes
		5.5.3 Fatigue Lives of LY12(2024)T62 Riveted Aluminum Alloy Sheets
		5.5.4 Fatigue Crack Growth Rate of LY12 Aluminum Alloy
	References
6 Strengthening Processes and Effect Evaluations of Airplane Structures with Laser Shock Peening
	6.1 Applications of Laser Shock Peening Treatment on Airplane Structures
	6.2 Requirements for Strengthening Processes of Aero-Engine Blades
	6.3 Spall Characteristics of Blades and Its Prevention Spall Technology
		6.3.1 Spall Strength and Spall Characteristics at the Bottom Surface of Thin Sheets
		6.3.2 Spall Threshold and Spall Characteristics at the Bottom Layer of Mid-Thick Plates
		6.3.3 Prevention Spall Technology of Blades
		6.3.4 Prevention Spall Process and Its Applications for Structures
	6.4 Evaluation of Strengthening Effect of Blades
		6.4.1 Evaluation of Anti-FOD Fatigue Performance at the Edge of Blades
		6.4.2 Anti-bending Deformation at the Edge of Blades
		6.4.3 Anti-vibration Fatigue Performance of Blades
	6.5 Blisk with Laser Shock Peening
		6.5.1 Laser Shock Peening with Large Inclination Angle
		6.5.2 Energy Compensation Method of Laser Oblique Incidence
	6.6 Plastic Forming of Wing Panels with Large-Area Laser Shock Peening
		6.6.1 Bending Deformation Types of Thin Sheets
		6.6.2 Upper Limit Value of Process Parameters of Convex Bending Deformation of Mid-Thick Plates
		6.6.3 Convex Bending Deformation and Mechanical Property of Mid-Thick Plates
	References
7 Quality Control Technology of Structures with Laser Shock Peening
	7.1 Present Situation of Detection Technology for Laser Shock Peening Quality
	7.2 Natural Frequency Tests of Aero-Engine Blades with Laser Shock Peening
		7.2.1 Test System
		7.2.2 The Changes of Natural Frequency and Residual Stresses of Blades
		7.2.3 Relation Between Impact Times and Natural Frequency
	7.3 Laser Shock Peening Effect Characterized by Acoustic Signal and Plasma Plume
	References
8 Strengthening Processes and Effect Evaluation of Welded Structures with Laser Shock Peening
	8.1 Present Situation of Weldments with Laser Shock Peening at Home and Abroad
	8.2 Tensile Strength and Fatigue Lives of Argon Arc Welded GH30 Alloy
		8.2.1 Micro-hardness and Residual Stress
		8.2.2 Tensile Strength and Fatigue Lives
		8.2.3 Fatigue Fracture Analysis
	8.3 Tensile Strength and Fatigue Lives of Plasma-Welded 1Cr18Ni9Ti Alloy
		8.3.1 Micro-hardness and Residual Stress
		8.3.2 Tensile Strength and Fatigue Lives
		8.3.3 Fatigue Fracture Analysis
	8.4 Mechanical Property and Fatigue Lives of TIG Welded TC4 Titanium Alloy with Multiple Impacts
		8.4.1 Micro-hardness and Microstructure
		8.4.2 Tensile Properties and Fatigue Lives
		8.4.3 Fatigue Fracture Analysis
	8.5 Mechanical Property and Fatigue Lives of Laser-Welded TC4 Sheets Treated by Laser Shock Peening with Double Sides and Different Sequences
		8.5.1 Micro-hardness and Residual Stress
		8.5.2 The Comparison of Median Fatigue Life
		8.5.3 Fatigue Fracture Analysis
	8.6 Mechanical Properties and Corrosion Properties of TA15 Electron Beam Welds
		8.6.1 Micro-hardness
		8.6.2 Corrosion Properties
		8.6.3 Tensile Properties
		8.6.4 Tensile Fracture Analysis
	References