Design of Thermal Barrier Coatings (eBook)

Mohit comes from Lucknow in India and received his bachelor’s degree in mechanical engineering in 2009 from Indian Institute of Technology Kanpur, India. He received his master’s degree in mechanical engineering in 2010 and doctoral degree in production technology in 2015 from University West, Sweden. He is currently employed as a senior researcher at University West. His research interests are finite element modelling, plasma spraying and solid oxide fuel cells.

Dedication 6
Preface 8
Contents 10
About the Author 12
Abbreviations 14
Chapter 1: Introduction 16
1.1 Scope and Limitations 19
References 20
Chapter 2: Background 21
2.1 Thermal Spraying 21
2.1.1 Atmospheric Plasma Spraying 21
2.1.2 High Velocity Oxy-Fuel Spraying 23
2.1.3 Liquid Feedstock Plasma Spraying 23
2.2 Thermal Barrier Coatings 23
2.3 Coating Formation 25
2.4 Process Parameters 25
2.5 Coating Materials for TBCs 26
2.5.1 Topcoat 26
2.5.2 Bondcoat 28
2.5.3 Thermally Grown Oxides 28
References 29
Chapter 3: Characteristics of TBCs 30
3.1 Microstructure 30
3.2 Heat Transfer Mechanism 33
3.2.1 General Theory 33
3.2.2 Application to TBCs 35
3.3 Mechanical Behaviour 36
3.3.1 Stress Formation 36
3.3.2 Young’s Modulus 37
3.3.3 Non-linear Properties 38
3.4 Interface Roughness 39
3.4.1 Roughness Relationship with Lifetime 39
3.4.2 Stress Inversion Theory 40
3.5 Oxide Formation 41
3.6 Failure Mechanisms 42
References 43
Chapter 4: Experimental Methods 46
4.1 Microstructure Characterisation 46
4.2 Thermal Conductivity Measurements 46
4.3 Young’s Modulus Measurements 48
4.4 Roughness Measurements 49
4.5 Lifetime Testing 50
References 53
Chapter 5: Modelling of Properties of TBCs 55
5.1 Thermal Conductivity 55
5.1.1 Analytical Models 55
5.1.2 Numerical Models 57
5.2 Young’s Modulus 59
5.2.1 Analytical Models 59
5.2.2 Numerical Models 59
5.3 Finite Element Modelling 60
5.3.1 Basics of FEM and FDM 60
5.3.2 Image Based Finite Element Model 61
5.3.2.1 Modelling Procedure 62
5.3.2.2 Property Evaluation 65
5.4 Artificial Coating Morphology Generator 66
5.5 Recent Work 68
References 73
Chapter 6: Modelling of Interface Roughness in TBCs 76
6.1 Simplified Interface Roughness Modelling 76
6.2 Real Interface Roughness Modelling 77
6.2.1 Two-Dimensional Approach 77
6.2.2 Three-Dimensional Approach 79
6.3 Results 80
References 82
Chapter 7: Modelling of Oxide Growth in TBCs 84
7.1 Diffusion-Based Modelling 85
7.1.1 Previous Work 85
7.1.2 Real Interface Roughness Modelling 85
7.1.3 Recent Work 87
7.2 Mixed Oxide Growth 89
References 91
Chapter 8: Conclusions: How to Design TBCs? 92
8.1 Future Work 93