B0655 High velocity oxy-fuel spraying

413 Pages·2004·11.322 MB·English

by  V. V. Sobolev, J. M. Guilemany, J. Nutting, Shrikant Joshi

High Velocity Oxy-Fuel Spraying
Theory, Structure-Property Relationships and Applications

High Velocity Oxy-Fuel Spraying
Theory, Structure-Property
Relationships and Applications
v.v.
Sobolev, J.M. Guilemany and J. Nutting
Consulting Editor: Shrikant Joshi
MANEY
FOR THE INSTITUTE OF MATERIALS, MINERALS AND MINING
B0655
First published in 2004 for
The Institute of Materials, Minerals and Mining by
Maney Publishing
1Carlton House Terrace
London SW1Y 5DB
Maney Publishing is the trading name of
W. S. Maney and Son Ltd
Hudson Road
Leeds LS9 7DL
© 10M3 2004
All rights reserved
ISBN 1-902653-72-6
Typeset in India by Emptek Inc.
Printed and bound in the UK by
The Charlesworth Group
Contents
Preface xi
PART I:HVOFPROCESSFUNDAMENTALS 1
1.0 INTRODUCTION 3
2.0 HVOF SPRAYINGSYSTEMS 7
2.1 DESCRIPTIONOFTHEPROCESS 7
2.2 GASEOUSANDLIQUIDFUELSFORHVOF SPRAYING 8
2.3 HVOF SPRAYSYSTEMS 10
2.3.1 Diamond Jet Hybrid Systems 11
2.3.2 JP-SOOO System 12
2.3.3 Top Gun K System 12
2.3.4 OSU Systems 13
2.4 RECENTDEVELOPMENTSINHVOF SPRAYING 13
2.4.1 High Pressure HVOF Spraying 13
2.4.2 Combining of Arc and HVOF Spraying ("Sonarc" Process) 14
2.4.3 Cold Gas Dynamic Spraying 15
2.4.4 High Frequency Pulse Detonation Spraying 15
2.5 HIGH VELOCITYAIR-FuEL SPRAYING 16
2.6 REFERENCES 17
3.0 POWDERSFORHVOF SPRAYING 19
3.1 METALLICPOWDERS 19
3.1.1 Manufacture of Powders 19
3.1.2 Properties of Metallic Coatings 21
3.2 CERMET POWDERS 22
3.2.1 Manufacture of Powders 22
3.2.2 Properties of Cermet Coatings 24
3.3 OXIDE CERAMICPOWDERS 24
3.4 METHODS OFPOWDEREVALUATION 26
3.5 PREPARATIONOFPOWDERSPECIMENFORTEM 26
3.6 COATINGCOST 27
3.7 REFERENCES 27
4.0 GAS-PARTICLE INTERACTIONSDURING SPRAYING 29
4.1 INTRODUCTION 29
4.2 COMBUSTIONANDSPRAYINGGAS DYNAMICS 29
4.2.1 Combustion Flame 29
vi High Velocity Oxy-Fuel Spraying (HVOF)
4.2.2 Gun Gas Dynamics 31
4.2.3 Gas Jet Expansion at the Spraying Distance 34
4.3 IN-FLIGHT BEHAVIOUROFPOWDERPARTICLES 36
4.3.1 Fluid Parameters 36
4.3.2 Mechanical and Thermal Behaviour 37
4.3.3 In-Flight Mass Transfer 41
4.4 RESULTSOFMATHEMATICALSIMULATIONPARTICLE
MECHANICAL BEHAVIOUR 45
4.5 SUMMARYOFTHEMAIN RESULTS 53
4.6 LIST OFSYMBOLS 54
4.7 REFERENCES 58
PART II: COATING DEPOSITION 63
5.0 SPLATFORMATION 65
5.1 INTRODUCTION 65
5.2 INFLUENCEOFSOLIDIFICATIONANDSURFACEROUGHNESS 66
5.3 EFFECT OFWETTING ANDSURFACEPHENOMENA 70
5.3.1 Influence of Wetting on the Droplet Flattening 70
5.3.2 Influence of Wetting on the Development of Porosity 74
5.3.3 Effect of Surface Phenomena on Flattening 74
5.4 INFLUENCEOFSUBSTRATEDEFORMATION 77
5.5 FLATTENINGOFCOMPOSITEPOWDERPARTICLES 80
5.6 SPLAT-SUBSTRATEMECHANICALINTERACTION 85
5.7 DYNAMICSOFSPLASHING 89
5.7.1 Splashing on a Smooth Surface 89
5.7.2 Splashing on a Rough Surface 92
5.7.3 Comparison with the Experimental Data 92
5.8 SPRAYINGATOFF-NORMAL ANGLES 93
5.9 INFLUENCEOFOXIDATIONONSPLATFORMATION 97
5.9.1 In-Flight Oxidation 98
5.9.2 Splat Oxidation 102
5.9.3 Influence on Droplet Flattening 104
5.9.4 Effect on Splat-Substrate Mechanical Interaction 105
5.9.5 Effect on Splat-Substrate Thermal Interaction 107
5.9.6 Comparison with Experimental Data 107
5.10 SUMMARYOFTHEMAIN RESULTS 108
5.11 LIST OFSYMBOLS 111
5.12 REFERENCES 114
6.0 SOLIDIFICATIONOFTHECOATINGANDDEVELOPMENTOF
COATING STRUCTURE 119
High Velocity Oxy-Fuel Spraying (HVOF) vii
6.1 COATING-SUBSTRATETHERMALINTERACTIONANDFORMATION
OFINTERFACIALREGION 119
6.1.1 Heat Transfer 120
6.1.2 Case Studies 123
6.2 FORMATIONOFCRYSTALLINEANDAMORPHOUSSTRUCTURES 133
6.2.1 WC-Co Coating on a Steel Substrate First Coating Layer
Solidification Isotherms 133
6.2.2 WC-Ni Coating on a Steel Substrate 146
6.2.3 WC-Co Coating on an Aluminium Alloy
(AI-4% Cu) Substrate 146
6.2.4 WC-Co Coating on a Copper Substrate 147
6.3 DEVELOPMENTOFCOATINGPOROSITY 152
6.4 GAS POROSITY 153
6.4.1 General Features of Development of Gas Porosity 153
6.4.2 Formation of Pores 154
6.4.3 Parameters of Porosity 156
6.4.4 Porosity in Spraying at Off-Normal Angles 157
6.S SHRINKAGEPOROSITY 157
6.6 POROSITYESTIMATESANDCOMPARISONWITHEXPERIMENTALDATA 159
6.7 FORMATIONOFCHEMICALINHOMOGENEITY 161
6.7.1 Mass Transfer 161
6.7.2 Chemical Segregation 162
6.7.3 Comparison with the Experimental Data 163
6.8 SUMMARYOFTHEMAIN RESULTS 164
6.9 LIST OFSYMBOLS 166
6.10 REFERENCES 169
7.0 DEVELOPMENTOF SUBSTRATE-COATINGADHESION 175
7.1 INTRODUCTION 175
7.2 SOME GENERALARGUMENTS 176
7.3 MECHANICALMECHANISMSOFADHESION 179
7.3.1 Coating-Substrate Mechanical Interaction 179
7.3.2 Keying (Interlocking) 180
7.3.3 Deformation of the Substrate Surface 180
7.3.4 Rebounding of Impinging Particles 182
7.4 THERMALMECHANISMS 184
7.5 DIFFUSIVEANDCHEMICALMECHANISMS 191
7.6 INFLUENCEOFOXIDATTONPROCESSES 193
7.7 EFFECTOFRESIDUALSTRESSESONADHESION 195
7.8 SUMMARYOFTHEMAIN RESULTS 196
7.9 LIST OFSYMBOLS 198
7.10 REFERENCES 200
viii High Velocity Oxy-Fuel Spraying (HVOF)
PART III: EVALUATION OF COATINGS 207
8.0 EVALUATIONOFCOATINGS 209
8.1 INTRODUCTION 209
8.2 OPTICALMICROSCOPY 211
8.3 SCANNINGWHITE LIGHTINTERFEROMETRY(SWLI) 220
8.4 X-RAY DIFFRACTION 220
8.5 TRANSMISSIONELECTRONMICROSCOPY(TEM) 220
8.5.1 Preparation of Specimen for Analysis of Substrate-Coating
Interface by TEM 223
8.6 SCANNINGELECTRONMICROSCOPY(SEM) 223
8.7 ELECTRONMICROPROBEANALYSIS(EPMA) 225
8.8 EVALUATIONOFTHECOATINGPROPERTIES 226
8.8.1 Mechanical Properties 226
8.8.1.1 wear 228
8.8.2 Physical Properties 228
8.9 REFERENCES 231
PART IV: STRUCTURE-PROPERTY RELATIONSHIPS 233
9.0 WC-Co SYSTEM 235
9.1 MAIN STRUCTURE-PROPERTYRELATIONSHIPS 235
9.1.1 Experimental Procedure 235
9.1.2 Powder Characterisation 236
9.1.3 Coating Evaluation 238
9.1.4 Coating Wear Resistance 240
9.2 COMPARISONOFCOATINGSSPRAYEDBYDIFFERENTGUNS 245
9.3 CORROSIONBEHAVIOUROFWC-12% Co COATINGSINMARINEWATER 246
9.4 FATIGUERESISTANCEOFCOATINGS 251
9.5 REFERENCES 253
10.0 WC-Co-Cr SYSTEM 255
10.1 MAIN STRUCTURE-PROPERTYRELATIONSHIPS 255
10.1.1 Experimental Procedure 255
10.1.2 Structural Characterisation of Powder and Coatings 256
10.1.3 Properties of Coatings 258
10.2 INFLUENCEOFPOWDERMANUFACTURINGMETHODONCOATINGPROPERTIES265
10.3 EFFECTOFPOWDERCHARACTERISTICSONEROSIONAND
CORROSIONRESISTANCEOFCOATINGS 267
10.4 COATINGSSPRAYEDBYDIFFERENTGUNS 268
10.5 REFERENCES 269
271
High Velocity Oxy-Fuel Spraying (HVOF) ix
11.1 MAIN STRUCTURE-PROPERTYRELATIONSHIPS 271
11.1.1 Experimental Procedure 271
11.1.2 Powder Characterisation 271
11.1.3 Evaluation of Coatings 272
11.2 INFLUENCEOFPOWDERTYPE ANDSPRAYSYSTEMONCOATINGPROPERTIES 282
11.3 REFERENCES 283
12.0 TiC-Ni SYSTEM 285
12.1 COATINGSSPRAYEDWITHPOWDERSPRODUCEDBYSELF
PROPAGATINGHIGH TEMPERATURESYNTHESIS 285
12.1.1 Materials and Experimental Procedure 285
12.1.2 Characterisation of Powders 286
12.1.3 Evaluation of Coatings 291
12.2 COATINGSOBTAINEDBYDJH 2700 ANDDETONATIONGUN SYSTEM 295
12.3 REFERENCES 296
13.0 MICROSTRUCTUREOFSUBSTRATEINTERFACIALREGION DURING
FORMATIONOFCERMETCOATINGS 299
13.1 WC-Co COATINGONAl-4% Cu ALLOY 299
13.2 WC-Co COATINGONCOPPER 303
13.3 WC-Co COATINGONTI-6%AL-4% V ALLOY 310
13.4 WC-NI COATINGONASTEEL 314
13.5 Cr C-NiCr COATINGONA STEEL 316
3 2
13.6 RESIDUALSTRESSESINGRIT BLASTEDSTEEL SUBSTRATES 319
13.7 REFERENCES 325
14.0 METALLICSYSTEMS 327
14.1 MAIN RELATIONSHIPSINSTAINLESSSTEELCOATINGS 327
14.1.1 Experimental Procedure 327
14.1.2 Characterisation of Structure of Powder and Coating 327
14.1.3 Coating Properties 331
14.2 STAINLESSSTEEL COATINGSSPRAYEDBYDIFFERENTGUNS 333
14.3 COATINGSOFSUPERALLOYS 334
14.3.1 Diamallays and Stellites 334
14.3.2 Other Cobalt Alloys 335
14.3.3 Inconel Coatings 335
14.3.4 Other Nichal-Based Coatings 337
14.4 REFERENCES 338
15.0 CERAMIC,POLYMERANDHYDROXYAPATITESYSTEMS 341
15.1 CERAMICCOATINGS 341
15.1.1 Alumina Coatings 341