Introduction to Low Pressure Gas Dynamic Spray : Physics and Technology

by Maev, Roman Gr.; Leshchynsky, Volf

• ISBN13: 9783527406593
• ISBN10: 352740659X
• Format: Hardcover
• Copyright: 2008-02-04
• Publisher: Wiley-VCH

Summary

Written by the inventor of the Gas Dynamic Spray (GDS) technique, this first monograph on the topic brings the understanding of the GDS coating formation process to a new qualitative nanostructural level, while introducing it to industrial and technological experts so that they can develop a new generation of coatings materials.Representing the results of over ten years of research in the field, the material discussed here covers nearly every aspect of the physical principles and applications of the GDS process, including topics in applied solid state physics, materials science, nanotechnology, and materials characterization.With contributions from researchers working in various laboratories, academic institutions and industries, this book is written for those wishing to apply this novel spraying technology in industry and who are involved in the development of new specific material properties, whether engineers or experts in the automotive, aircraft, household machinery, nuclear power, materials development or other industries.

Author Biography

Roman Gr. Maev received his Ph.D. from the Physical Institute of the Russian Academy of Sciences in 1973 and his D.Sc. in acoustic microscopy from the Russian Academy of Sciences, Moscow, in 2002. From 1994 to 1997, he held a post as Director of the Acoustic Microscopy Center of the Russian Academy of Sciences, then established the Centre for Imaging Research and Advanced Material Characterization at the University of Windsor, Canada. He is currently a Full Faculty Professor at the Physics Department at the same University and since 2001 the Chairholder of the NSERC/DaimlerChrysler/Industrial Research Chair in Applied Solid State Physics and Material Characterization. Professor Maev's research interests focus on the fundamentals of condensed matter, physical acoustics, ultrasonic imaging, and acoustic microscopy. He has published numerous books, more than 300 scientific papers, and holds twenty patents.

Volf Leshchynsky received his Ph.D. from the Technical Physics Institute at the Russian Academy of Sciences, Moscow, in 1968, and his D.Sc. from the Institute of Metallurgy at the same University in 1989. He then held a chair as professor of the Metal Forming Institute, Poznan, Poland, and became Head of the Metal Forming Department at the East Ukrainian University. He is currently a visiting professor at the Physics Department of the University of Windsor, Canada, where he conducts research in new powder metallurgy, nanostructuring, and cold spray techniques. Dr. Leshchynsky's research interests include the fundamentals of nanotechnology and nanostructured materials, and the development and application of powder spraying and powder metallurgy. He is the author of more than 150 scientific papers and holds thirty patents.

Table of Contents

Preface	p. XI
Introduction	p. 1
General Description	p. 1
Overview of Competitive Technologies	p. 4
Coating Characterization	p. 4
Flame Spraying	p. 5
Arc Wire Spraying	p. 6
Plasma Spraying	p. 6
Rapid Prototyping	p. 7
Plasma Deposition Manufacturing	p. 8
Explosive Cladding	p. 9
Concluding Remarks	p. 10
Impact Features of Gas Dynamic Spray Technology	p. 11
Impact Phenomena in GDS	p. 11
Main Features	p. 11
Rebound and Erosion Processes	p. 12
GDS Processes	p. 16
One Particle Impact in GDS	p. 17
Shear Localization Phenomenon	p. 17
Adiabatic Shear Instability in GDS	p. 22
Experiments Relating to Particle Impact	p. 29
Concluding Remarks	p. 35
Densification and Structure Formation of the Particulate Ensemble	p. 37
Identification of Various Phenomena	p. 37
Observations of GDS Consolidated Materials	p. 40
Energy Requirements for GDS Shock Consolidation	p. 45
Plastic Deformation Energy	p. 45
Microkinetic Energy	p. 46
Frictional Energy	p. 47
Adiabatic Shear Band Formation Energy	p. 48
Defect Energy	p. 49
Computation of ASB Energy Parameters	p. 49
Shear Localization During Particle Shock Consolidation	p. 50
Impact Powder Compaction Model	p. 51
Behavior of Consolidating Powder Under Compression	p. 54
Constitutive Function	p. 54
Yield Function and Property Estimations	p. 55
Consolidation Parameters of GDS and Shear Compression	p. 56
Estimation of Compaction Parameters	p. 57
GDS Experiments	p. 57
Shear Compaction Modeling	p. 57
Modeling Results and Discussion	p. 58
ASB Width Evaluation	p. 58
Yield Stress of Powder Material	p. 59
Concluding Remarks	p. 60
Low-Pressure GDS System	p. 65
State-of-the-Art Cold Spray Systems	p. 65
State-of-the-Art Powder Feeding Systems	p. 70
Modification of the Low-Pressure Portable GDS System	p. 73
An Industrial Low-Pressure Portable GDS System	p. 77
General Analysis of Low-Pressure GDS	p. 79
Statement of Problem	p. 79
Experimental Procedure	p. 80
Experimental Results	p. 83
Deposition Efficiency	p. 84
The Effect of the Particle Mass Flow Rate	p. 86
The Build-up Parameter	p. 87
Structure and Properties	p. 88
Basic Mechanisms	p. 91
Concluding Remarks	p. 94
Diagnostics of Spray Parameters: Characterization of the Powder-Laden Jet	p. 95
General Relationships	p. 95
The Governing Equations of Single-Phase Turbulent Flow	p. 97
The k-[characters not reproducible] Model for Turbulent Flows	p. 98
Particle Dynamics in Gas Flow	p. 98
Gas Flow and Particle Acceleration	p. 100
Computational Fluid Dynamics (CFD)	p. 102
An Engineering Model with Particle Friction	p. 105
Calculated Data and Discussion	p. 108
Simulation of Gas-Particle Flow in the Nozzle	p. 108
Influence of Gas Pressure	p. 111
Effects of Particle Concentration	p. 112
Effects of Nozzle Wall Friction	p. 114
Free Jet Characterization	p. 116
Shock Wave Features of the Jet	p. 116
An Engineering Model of the Free Jet	p. 119
Particle Flow Structure Within the Normal Shock Region	p. 121
Particle Collisions	p. 123
Concluding Remarks	p. 124
Deposition Efficiency and Shock Wave Effects at GDS	p. 125
Model Structure	p. 125
Statement of Task	p. 125
Gas Flow	p. 125
Particle Motion	p. 127
Deposition Efficiency	p. 127
Calculations and Discussion	p. 128
Critical Velocity Evaluation on the Basis of Rebound and Adhesion Phenomena	p. 131
Concluding Remarks	p. 132
Structure and Properties of GDS Sprayed Coatings	p. 135
General Remarks	p. 135
Powder Materials for Low-Pressure Gas Dynamic Spray	p. 136
Features of GDS Coatings	p. 136
Microstructure	p. 136
Interparticle Bonding	p. 136
Overview of GDS Materials	p. 138
Definition of Structure Parameters	p. 140
Structure and Mechanical Properties of Composite Coatings	p. 142
Methods of Testing	p. 142
Strength Tests	p. 142
Determining the Elastic Modulus	p. 144
Preparation of Samples	p. 144
Analysis of the Elastic Modulus	p. 147
General Relationships	p. 147
Rule of Mixture (ROM) Bounds	p. 147
Hashin-Shtrikman (H-S) Model	p. 148
Effect of Porosity on Elastic Constants	p. 148
Development of MCA Model for GDS Process	p. 150
Elastic Modulus and Microstructure of LPGDS Composites	p. 153
Load-Deformation Behavior of GDS Composites	p. 158
Strengthening GDS composites	p. 158
Failure Criterion and Microstructural Aspects of Crack Propagation	p. 165
Analysis of LPGDS Composite Fracture Characteristics	p. 166
Effect of Substrate Properties and Surface on the Deposition Process	p. 171
General Analysis and Effects of Residual Stresses	p. 171
Microstructure Analysis of Interface	p. 173
Low-Pressure GDS Applications	p. 181
General Analysis	p. 181
Repair Applications of GDS Technology	p. 185
LPGDS Composite Coatings for Mechanical Components	p. 186
LPGDS Technology Characterization and Experimental Procedure	p. 187
Results and Discussion	p. 189
Characterization	p. 189
Sliding Wear Behavior	p. 189
Analysis of Worn Surfaces	p. 192
Wear Microstructure	p. 194
Wear Process	p. 194
Casting Repair	p. 195
Casting Die Components Repair	p. 196
Car Body Shape Repair	p. 198
Hardening by LPGDS Deposition	p. 198
General Remarks	p. 198
LPGDS of Ni-SiC Powder Mixtures	p. 200
Deposition Efficiency	p. 200
Microhardness and Microscratching	p. 202
Corrosion Protection Through GDS Deposition	p. 206
General Remarks	p. 206
Examination of Al-Zn-based Sacrificial Coatings	p. 207
GDS Processing of Smart Components	p. 210
General Remarks	p. 210
Technology Description	p. 211
Results and Discussion	p. 214
Concluding Remarks	p. 217
Bibliography	p. 219
Index	p. 231
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