Maev Roman Gr., Leshchynsky V. Introduction to Low Pressure Gas Dynamic Spray

Wiley-VCH Verlag GmbH & Co. KGaA, 2008. 248 p. ISBN: 978-3-527-40659-3Written 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 industriesGeneral Description
Overview of Competitive Technologies
Coating Characterization
Flame Spraying
ArcWire Spraying
Plasma Spraying
Rapid Prototyping
Plasma Deposition Manufacturing
Explosive Cladding
Concluding Remarks
Impact Features of Gas Dynamic Spray Technology
Impact Phenomena in GDS
Main Features
Rebound and Erosion Processes
GDS Processes
One Particle Impact in GDS
Shear Localization Phenomenon
Adiabatic Shear Instability in GDS
Experiments Relating to Particle Impact
Concluding Remarks
Densification and Structure Formation of the Particulate Ensemble
Identification of Various Phenomena
Observations of GDS Consolidated Materials
Energy Requirements for GDS Shock Consolidation
Plastic Deformation Energy
Microkinetic Energy
Frictional Energy
Adiabatic Shear Band Formation Energy
Defect Energy
Computation of ASB Energy Parameters
Shear Localization During Particle Shock Consolidation
mpact Powder Compaction Model
Behavior of Consolidating Powder Under Compression
Constitutive Function
Yield Function and Property Estimations
Consolidation Parameters of GDS and Shear Compression
Estimation of Compaction Parameters
GDS Experiments
Shear Compaction Modeling
Modeling Results and Discussion
ASBWidth Evaluation
Yield Stress of Powder Material
Concluding Remarks
Low-Pressure GDS System
State-of-the-Art Cold Spray Systems
State-of-the-Art Powder Feeding Systems
Modification of the Low-Pressure Portable GDS System
An Industrial Low-Pressure Portable GDS System
General Analysis of Low-Pressure GDS
Statement of Problem
Experimental Procedure
Experimental Results
Deposition Efficiency
The Effect of the Particle Mass Flow Rate
The Build-up Parameter
Structure and Properties
Basic Mechanisms
Concluding Remarks
Diagnostics of Spray Parameters: Characterization of the Powder-Laden Jet
General Relationships
The Governing Equations of Single-Phase Turbulent Flow
The k– Model for Turbulent Flows
Particle Dynamics in Gas Flow
Gas Flow and Particle Acceleration
Computational Fluid Dynamics (CFD)
An Engineering Model with Particle Friction
Calculated Data and Discussion
Simulation of Gas-Particle Flow in the Nozzle
Influence of Gas Pressure
Effects of Particle Concentration
Effects of NozzleWall Friction
Free Jet Characterization
ShockWave Features of the Jet
An Engineering Model of the Free Jet
Particle Flow StructureWithin the Normal Shock Region
Particle Collisions
Concluding Remarks
Deposition Efficiency and Shock Wave Effects at GDS
Model Structure
Statement of Task
Gas Flow
Particle Motion
Deposition Efficiency
Calculations and Discussion
Critical Velocity Evaluation on the Basis of Rebound and Adhesion Phenomena
Concluding Remarks
Structure and Properties of GDS Sprayed Coatings
General Remarks
Powder Materials for Low-Pressure Gas Dynamic Spray
Features of GDS Coatings
Microstructure
Interparticle Bonding
Overview of GDS Materials
Definition of Structure Parameters
Structure and Mechanical Properties of Composite Coatings
Methods of Testing
Strength Tests
Determining the Elastic Modulus
Preparation of Samples
Analysis of the Elastic Modulus
General Relationships
Rule of Mixture (ROM) Bounds
Hashin–Shtrikman (H–S) Model
Effect of Porosity on Elastic Constants
Development of MCA Model for GDS Process
Elastic Modulus and Microstructure of LPGDS Composites
Load-Deformation Behavior of GDS Composites
Strengthening GDS composites
Failure Criterion and Microstructural Aspects of Crack Propagation
Analysis of LPGDS Composite Fracture Characteristics
Effect of Substrate Properties and Surface on the Deposition Process
General Analysis and Effects of Residual Stresses
Microstructure Analysis of Interface
Low-Pressure GDS Applications
General Analysis
Repair Applications of GDS Technology
LPGDS Composite Coatings for Mechanical Components
LPGDS Technology Characterization and Experimental
Procedure
Results and Discussion
Characterization
SlidingWear Behavior
Analysis of Worn Surfaces
Wear Microstructure
Wear Process
Casting Repair
Casting Die Components Repair
Car Body Shape Repair
Hardening by LPGDS Deposition
General Remarks
LPGDS of Ni–SiC Powder Mixtures
Deposition Efficiency
Microhardness and Microscratching
Corrosion Protection Through GDS Deposition
General Remarks
Examination of Al–Zn-based Sacrificial Coatings
GDS Processing of Smart Components
General Remarks
Technology Description
Results and Discussion
Concluding Remarks