Pohl, Katharina: Surface chemistry and corrosion studies of Zn-Al and Zn-Mg-Al alloy coatings. 2013
Content
Acknowledgement v
Abstract vi
1 State of research and motivation 1
2 Fundamentals 4
2.1 Corrosion of zinc and zinc alloy coated steel 4
2.1.1 General corrosion mechanism under atmospheric conditions 4
2.1.2 General corrosion mechanism under full immersion 9
2.1.3 In–situ Raman spectroscopic analysis of zinc corrosion products 13
2.2 Molecular adhesion on aluminum and zinc oxides 14
2.3 Fundamentals of adhesion and de–adhesion of polymers on oxide covered metals 19
2.4 Raman spectroscopic analysis of polymer/metal interface 22
3 Theoretical background of applied analytical techniques 25
3.1 Spectroscopic techniques 25
3.1.1 Raman spectroscopy 25
3.1.2 Infrared spectroscopy 27
3.1.3 X–ray photoelectron spectroscopy (XPS) 29
3.2 Electrochemical techniques 30
3.2.1 Scanning Kelvin probe (SKP) 31
3.2.2 Cyclic voltammetry (CV) 32
3.2.3 Scanning Kelvin probe force microscopy (SKPFM) 33
3.3 Microscopic techniques 35
3.4 Contact angle measurement 37
4 In–situ corrosion analysis of zinc alloy coated steel 39
4.1 Experimental 39
4.1.1 Materials and sample preparation 39
4.1.2 Surface Analysis 40
4.1.3 In–situ Raman spectroscopy 40
4.2 Surface morphology and microstructure 41
4.3 Bulk composition of the alloy 44
4.4 Electronic surface properties 47
4.5 Corrosion processes and mechanisms at different pH 50
4.6 Conclusions 58
5 In–situ corrosion analysis of zinc magnesium alloy coated steel 59
5.1 Experimental 59
5.1.1 Materials and sample preparation 59
5.1.2 Surface Analysis 60
5.1.3 In–situ Raman spectroscopy 60
5.2 Surface morphology and bulk composition of the alloy 60
5.3 Corrosion process and mechanisms at different pH 63
5.4 Conclusions 70
6 In–situ corrosion analysis of oxide covered iron/ zinc alloy cut edges 72
6.1 Experimental 72
6.1.1 Materials and sample preparation 72
6.1.2 Surface Analysis 72
6.1.3 In–situ Raman spectroscopy 73
6.2 Cut edge morphology and chemistry 73
6.3 Corrosion process and mechanism 75
6.4 Conclusions 79
7 Adsorption and stability of self–assembled organophosphonic acid monolayers on plasma modified Zn–Mg–Al alloy surfaces 80
7.1 Experimental 80
7.1.1 Materials and Sample Preparation 80
7.1.2 Plasma Surface Chemistry 81
7.1.3 Adsorption and Self–Organization of Organic Acids 81
7.1.4 Surface Analysis 81
7.2 Plasma surface chemistry 83
7.3 Adsorption and self–organization of organic acids 91
7.4 Stability of organic acids on Zn–Mg–Al alloys 96
7.5 Blocking of surface sites oxide covered on Zn–Mg–Al alloys by ODPA SAMs 98
7.6 Conclusions 100
8 Surface chemistry and adhesive properties of plasma modified Zn–Mg–Al alloy coatings 101
8.1 Experimental 101
8.1.1 Modification of the surface by plasma treatment 101
8.1.2 Application of adhesion promoter and the model polymer coating 102
8.1.3 Characterization of the surface chemistry after plasma treatments and APPA adsorption 102
8.1.4 Peel–test measurements 103
8.2 Characterization of the plasma modified samples 103
8.3 Adsorption of APPA on the plasma modified sample surface 108
8.4 The effect of plasma treatments and APPA adsorption on the adhesion of epoxy amine coating on Zn–Mg–Al alloy surfaces 113
8.5 Conclusions 115
9 Overall conclusions and outlook 116
References 119
Abbreviations and symbols 127
List of Figures 129
List of Tables 134
List of Publications 135
Curriculum Vitae 137
1 State of research and motivation
2 Fundamentals
2.1 Corrosion of zinc and zinc alloy coated steel
2.1.1 General corrosion mechanism under atmospheric conditions
2.1.2 General corrosion mechanism under full immersion
2.1.3 In–situ Raman spectroscopic analysis of zinc corrosion products
2.2 Molecular adhesion on aluminum and zinc oxides
2.3 Fundamentals of adhesion and de–adhesion of polymers on oxide covered metals
2.4 Raman spectroscopic analysis of polymer/metal interface
3 Theoretical background of applied analytical techniques
3.1 Spectroscopic techniques
3.2 Electrochemical techniques
3.2.1 Scanning Kelvin probe (SKP)
3.2.2 Cyclic voltammetry (CV)
3.2.3 Scanning Kelvin probe force microscopy (SKPFM)
3.3 Microscopic techniques
3.4 Contact angle measurement
4 In–situ corrosion analysis of zinc alloy coated steel
4.1 Experimental
4.2 Surface morphology and microstructure
4.3 Bulk composition of the alloy
4.4 Electronic surface properties
4.5 Corrosion processes and mechanisms at different pH
4.6 Conclusions
5 In–situ corrosion analysis of zinc magnesium alloy coated steel
5.1 Experimental
5.2 Surface morphology and bulk composition of the alloy
5.3 Corrosion process and mechanisms at different pH
5.4 Conclusions
6 In–situ corrosion analysis of oxide covered iron/ zinc alloy cut edges
6.1 Experimental
6.2 Cut edge morphology and chemistry
6.3 Corrosion process and mechanism
6.4 Conclusions
7 Adsorption and stability of self–assembled organophosphonic acid monolayers on plasma modified Zn–Mg–Al alloy surfaces0F
7.1 Experimental
7.1.1 Materials and Sample Preparation
7.1.2 Plasma Surface Chemistry
7.1.3 Adsorption and Self–Organization of Organic Acids
7.1.4 Surface Analysis
7.2 Plasma surface chemistry
7.3 Adsorption and self–organization of organic acids
7.4 Stability of organic acids on Zn–Mg–Al alloys
7.5 Blocking of surface sites oxide covered on Zn–Mg–Al alloys by ODPA SAMs
7.6 Conclusions
8 Surface chemistry and adhesive properties of plasma modified Zn–Mg–Al alloy coatings1F
8.1 Experimental
8.1.1 Modification of the surface by plasma treatment
8.1.2 Application of adhesion promoter and the model polymer coating
8.1.3 Characterization of the surface chemistry after plasma treatments and APPA adsorption
8.1.4 Peel–test measurements
8.2 Characterization of the plasma modified samples
8.3 Adsorption of APPA on the plasma modified sample surface
8.4 The effect of plasma treatments and APPA adsorption on the adhesion of epoxy amine coating on Zn–Mg–Al alloy surfaces
8.5 Conclusions
9 Overall conclusions and outlook
References
Abbreviations and symbols
List of Figures
List of Tables
List of Publications
Curriculum Vitae