Quantitative 3D characterization of graphite morphologies in cast iron using FIB microstructure tomography [Elektronische Ressource] / von Alexandra Velichko

Alexandra Velichko

Informations

• Publié par: universitat_des_saarlandes
• Publié le: 01 janvier 2008
• Nombre de lectures: 44
• Poids de l'ouvrage: 10 Mo

Extrait

Quantitative 3D Characterization of
Graphite Morphologies in Cast Iron
using FIB Microstructure Tomography



DISSERTATION

zur Erlangung des Grades des
DOKTORS DER INGENIEURWISSENSCHAFTEN
der Naturwissenschaftlich-Technischen Fakultät III
Chemie, Pharmazie, Bio- und Werkstoffwissenschaften
der Universität des Saarlandes





von

ALEXANDRA VELICHKO




Saarbrücken
2008






















Tag des Kolloquiums: 22.08.08

Dekan: Prof. Dr. Uli Müller

Berichterstatter: Prof. Dr. Frank Mücklich
Prof. Dr. Stefan Diebels





ii




Посвещяется родителям и деду




























In den Wissenschaften ist viel Gewisses,
sobald man sich von den Ausnahmen nicht irre machen lässt
und die Probleme zu ehren weiß.

Johann Wolfgang von Goethe
iii
iv PREFACE
The present work reports about the study of the microstructure of the graphite morphologies
in cast iron and its influence on the effective properties of this material. It was performed be-
tween 01.03.2003 and 30.11.2007 at the Institute of Functional Materials at the University of
Saarland.
Parts of the work have been already published by:
A. Velichko, C. Holzapfel, A. Siefers, K. Schladitz, F. Mücklich, „ Unambiguous classi-
fication of complex microstructures by its 3D parameters applied to graphite in cast
iron“, Acta Materialia, 56(2008), 1981-1990
Th. Magenreuter, A. Velichko, F. Mücklich, „The Dependence of the Shape Parameters
Roundness and Compactness of Various Graphite Morphologies on Magnification”,
Pract. Metallography, 45(2008), 53-71
A. Velichko, F. Mücklich, „Neue Möglichkeiten der objektiven Graphitklassifizierung in
Gusseisen durch Nano-Tomographie und internetbasierte Online-Verfahren“, VDI-
Berichte Giesstechnik im Motorenbau, 1949(2007), 21-36
A. Velichko, C. Holzapfel, F. Mücklich, „3D Characterization of Graphite Morphologies
in Cast Iron“, Advanced Engineering Materials, 9(2007), 1-2, 39-45
A. Velichko, F. Mücklich, „Shape Analysis and Classification of Irregular Graphite
Morphology in Cast Iron“, Pract. Metallography, 43(2006), 4, 192-208
This work could not have come into being without support of number of persons, whom I
would like to express at this point my generous gratitude.

First of all, I would like to express my gratitude to my supervisor Prof. Dr.-Ing. Frank
Mücklich, for his trust in me, personal and scientific support. I am very thankful for his dis-
cussions which have been a constant source of scientific inspiration.
I am thankful to Prof. Dr.-Ing. Stefan Diebels for co-refereeing this thesis.
I acknowledge the efficient collaboration with the following partners who have contributed
their interesting problems within the project Nr. 03N3119 sponsored by German Federal Min-
istary of Education and Research: Herbert Junk, Andreas Spick, Dirk Radebach, Halberg Guss
GmbH, Saarbrücken; Rolf Heinemann, Volkswagen AG, Wolfsburg; Dr. Iris Altpeter, Prof.
Walter Arnold, Dr. Udo Netzelman, Dr. Michael Maisl and Ute Maisl, Fraunhofer IZfP,
Saarbrücken.
v I am thankful to Prof. Dr.-Ing. Weikum for successful cooperation by the development of the
on-line classification of graphite.
I would like to thank:
Dr. Christian Holzapfel, Dr. Flavio Soldera, Christoph Pauly for the help with microstructure
analysis using Dual Beam workstation;
Peter Leibenguth for TEM study and valuable discussions;
Dr. Jorge Fiscina for the help with the electrical measurements;
Dr. Katja Schladitz, Dr. Claudia Lautensack Fraunhofer ITWM, Kaiserslautern for the help
with 3D analysis and interesting discussions;
Hans Jakoby, Sasha Schneider, Wolfgang Ott for the sectioning of the numerous cast iron
samples and constructing the four point measuring setup;
Claudia Maas for metallographical tips and enjoyable working atmosphere through all this
years;
Dr. Andrés Lasagni for some suggestions with data analysis;
Nicolas Jeanvoine for the help with FlexPDE simulations;
Dr. Andreas Wiegmann for providing 3D simulation software;
Students Thomas Magenreuter, Corina Richter, Isabelle Galmiche, Andrea Siefers, and
Bérenger Florence who contributed with their work to the different aspects of the current the-
sis.
I gratefully acknowledge all the colleges of the chair of Functional Materials, of University of
Saarland for the wonderful atmosphere and support. I owe special thanks to Michael Engstler,
Carsten Gachot and Jules Dake for the accurate reviewing of this manuscript.
Thanks to many others, who have contributed in one way or another to a good working at-
mosphere, with advice or just by sharing good time: Alexandra, Amadou, Antoine, Awa,
Christian, Hakima, Irina, Karsten, Laure, Mathias, Mikael, Muriel, Olga, Sebastien, Xavier
and all those I forgot to mention.

Finally, I would like to thank my family for their constant support, unconditional love and
their faith in me.

Saarbrücken, May 2008 Alexandra Velichko

vi TABLE OF CONTENTS
PREFACE ...................................................................................................................................... V
TABLE OF CONTENTS ................ VII
ABSTRACT .. XI
ZUSAMMENFASSUNG ................................................................................................................. XII
TABLE OF SYMBOLS AND ABBREVIATIONS ............... XIII

1 INTRODUCTION ................................................................................................................. 1
I. THEORY ........................... 3
2 CAST IRON MICROSTRUCTURE AND PROPERTIES ............................................................. 5
2.1 Different Graphite Morphologies in Cast Iron ............................ 7
2.1.1 Cast Iron with Flake Graphite (FG) ..................................... 7
2.1.2 ron with Spheroidal Graphite (SG) ............................................................. 9
2.1.3 Cast Iron with Vermicular Graphite (CG) .......................... 11
2.1.4 Malleable Cast Iron (TG) ................................................... 13
2.2 Influence of the Graphite Morphology on the Properties of Cast Iron ...................... 14
2.2.1 Mechanical Properties and Density of Cast Iron ................................................ 14
2.2.2 Thermal and Electrical Conductivity ................................. 17
2.2.3 Electromagnetic Properties for Non-Destructive Microstructure Characterization
............................................................................................ 18
2.3 Analytical Models and Prediction of Material Properties ......................................... 19
2.3.1 Calculation of the Effective Properties of the Composites 20
2.3.2 Existing Correlations for Cast Iron .................................... 24
3 QUANTITATIVE MICROSTRUCTURE CHARACTERIZATION ............................................... 29
3.1 Basic Characteristics of Quantitative Image Analysis .............. 29
3.1.1 Particle Based Parameters .................................................. 29
3.1.2 Field Based Parameters ...................................................... 30
3.1.3 Stereological Equations for Calculation of the Basic Characteristics ................ 31
3.2 Characterization and Classification of Graphite Morphology in 2D ......................... 32
3.2.1 Classification According to Norm DIN EN ISO 945 ......................................... 32
3.2.2 Shape Characterization ....................................................... 33
3.2.3 Other Approaches to Graphite Classifications ................... 35
3.3 Characterization in 3D ............................................................... 37
3.3.1 X-ray and Synchrotron Microtomography ......................... 39
3.3.2 FIB-Tomography – New Tool ............................................................................ 40
3.3.3 Analysis of Spatial Tomography Images ........................... 42
vii II. EXPERIMENTAL ...................................................................................................... 43
4 EXPERIMENTAL PROCEDURE .......................................................................................... 45
4.1 Sample Preparation .................................... 45
4.1.1 Chemical Composition ....................... 45
4.1.2 Metallographic Preparation ................................................................................ 45
4.1.3 Surface Quality ................................... 46
4.1.4 Chemical Etching ............................................................... 48
4.2 Microscopic Characterization of the Microstructure ................. 49
4.2.1 Optical and Scanning Electron Micr