Study of structural changes in Zr-based bulk metallic glasses upon annealing and deformation ...

241 Pages·2008·6.49 MB·English

by  Nele Van Steenberge

Study of structural changes in Zr-based
bulk metallic glasses upon annealing
and deformation treatments
Doctoral thesis presented by
Nele Van Steenberge
Bellaterra, April 2008
Study of structural changes of Zr-based bulk
metallic glasses upon annealing and
deformation treatments
Doctoral thesis presented by
Nele Van Steenberge
Bellaterra, April 2008
Departament de F´ısica
Facultat de Ci`encies
Els Doctors Maria Dolors Baro´ Marin´e i Jordi Sort Vin˜as , directors de
la tesi doctoral realitzada per Nele Van Steenberge, i que porta per t´ıtol ”Study
of structural changes of Zr-based bulk metallic glasses upon annealing
and deformation treatments”,
FAN CONTESTAR
Que l’aportacio´ del doctorand al treball que es presenta ha estat fonamen-
tal tant pel que fa al disseny experimental, com a l’obtencio´ de les mostres, la
realitzaci´o dels experiments, l’ana`lisi de les dades i la discussi´o i elaboracio´ dels
articles presentats.
I perqu`e aix´ı consti, a peticio´ de l’interessat i als efectes oportuns, ho signem
a Bellaterra, el 15 d’ abril de 2008.
Dra. Maria Dolors Baro´ Dr. Jordi Sort

ACKNOWLEDGEMENTS
During the course of this research work, a lot of people have lent me their helping
hands and therefore I would like to take the opportunity to acknowledge them.
First and foremost, I would like to thank my supervisors Prof. Maria Dolors
Baro´ and Dr. Jordi Sort for giving me the opportunity to work in their group and
for their support and advice, not only about research but also on non-scientific
matter, andespeciallyfortheirconfidenceinme. Aspecialthanksinparticularto
Dr. AmadeuConcustell,forsharinghisknowledgeandexperienceonbulkmetallic
glasses. His enlightening discussions have been a great help for the realization
of this thesis. I also owe thanks to Prof. Santiago Surin˜ach for his help with
experimental set-ups and technical assistance.
Furthermore, I may certainly not forget to thank my other colleagues from
the group ”F´ısica dels Materials II”: Germ´an, Enric, Jordina, Sebastiano, Pau,
Alberto, Eva, Josep and V´eronique for giving me a hearty welcome and making
me feel like at home, just as much at work as well as beyond. To the technicians
Jordi Lo´pez, Manel Garcia and Rafael Moraira, thank you for your help on the
reparation of small and bigger technical issues. Moltes gracies!
It was very interesting to participate in the European Research Training Net-
work on ”Ductilisation by length-scale control of Bulk Metallic Glasses and Bulk
Metallic Glass Composites”. It gave me the opportunity to meet and discuss with
some very specialized scientists on the topic. Special thanks to Prof. Ju¨rgen Eck-
ert, Dr. Annett Gebert and Dr. Jayanta Das from the IFW Dresden (Germany),
for their input and advice as well as for the practical help during my stays in
their institute. Thanks also to Dr. Tanya Baser (University of Torino) for the
interesting talks we had during our stay in Dresden, as well as for her efforts on
the modulated DSC.
Besides, I am indebted to the people of the Microscopy Service, in particular
Dr. Emma Rossinyol and Onofre Castells for their permanent assistance in the
iv Acknowledgements
TEM experiments, as well as to the people from the X-ray diffraction Service at
the UAB for their help. Dr. Oriol Osso´ from Matgas and Dr. Jaume Caro from
the CTM Manresa for their collaboration on the nanoindentation experiments.
I am grateful for the technical support on in-situ TEM and high-resolution
TEM by Dr Fr´ed´eric Mompiou and Florent Houdellier during my stays at the
CEMES in Toulouse within the framework of the ESTEEM project.
This work would not have been possible without the financial and partial fi-
nancialsupportofthreeEuropeanprojects: ”Ductilisationbylength-scalecontrol
of Bulk Metallic Glasses and Bulk Metallic Glass Composites” (MRTN-CT-2003-
504692), the special support action ”Strengthening the role of women scientists in
nano-science”andESTEEM(EnablingScienceandTechnologythroughEuropean
Electron Microscopy) project (026019).
Thank you Stella, Fran, Cassie, Peca, Claire and all the others for making this
time here in Barcelona just unforgettable!
Dani, thank you for your infinite support, patience and encouragement.
En het laatste woordje van dank gaat naar mijn ouders, mijn broer en zus en
vrienden in Belgi¨e - bedankt voor jullie steun, woorden van moed, de bezoekjes
en zoveel meer. Een heel dikke merci!
TABLE OF CONTENTS
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix
1. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 Bulk metallic glasses - state of the art . . . . . . . . . . . . . . . . 1
1.2 Glass formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2.1 Definition of a glass - glass transition. . . . . . . . . . . . . 2
1.2.2 Classical crystallization theory . . . . . . . . . . . . . . . . 3
1.2.3 Glass forming ability . . . . . . . . . . . . . . . . . . . . . . 5
1.2.4 Application of classical nucleation theory for metallic glass 6
1.2.5 Glass forming systems . . . . . . . . . . . . . . . . . . . . . 8
1.3 Structural Aspects of Metallic glasses . . . . . . . . . . . . . . . . 9
1.3.1 Short- and medium-range order - theoretical aspects . . . . 9
1.3.2 Medium-range order - experimental observation . . . . . . . 12
1.3.3 Free volume . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
1.4 Mechanical behavior of metallic glasses . . . . . . . . . . . . . . . . 14
1.4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 14
1.4.2 Atomic-level mechanisms . . . . . . . . . . . . . . . . . . . 16
1.4.3 Elastic deformation - mechanical strength - elastic constants 17
1.4.4 Plastic deformation - Catastrophic failure . . . . . . . . . . 18
1.4.5 Possible mechanisms to improve plasticity - overview of lit-
erature data . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
1.5 Possible applications . . . . . . . . . . . . . . . . . . . . . . . . . . 29
2. Experimental techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
2.1 Preparation techniques . . . . . . . . . . . . . . . . . . . . . . . . . 33
2.1.1 Arc-melting . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
2.1.2 Cu mold casting . . . . . . . . . . . . . . . . . . . . . . . . 34
2.1.3 Experimental procedure . . . . . . . . . . . . . . . . . . . . 35
2.2 Treatments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
2.2.1 Annealing treatment . . . . . . . . . . . . . . . . . . . . . . 37
2.2.2 Heavy deformation - high pressure torsion . . . . . . . . . . 37
vi CONTENTS
2.3 Characterization techniques . . . . . . . . . . . . . . . . . . . . . . 39
2.3.1 Thermal characterization . . . . . . . . . . . . . . . . . . . 39
2.3.2 Microstructural characterization - X-ray diffraction . . . . . 51
2.3.3 Microstructural characterization: Electron Microscopy . . . 59
2.3.4 Mechanical characterization . . . . . . . . . . . . . . . . . . 89
3. Indentation size effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
3.2 Experimental conditions . . . . . . . . . . . . . . . . . . . . . . . . 105
3.3 Thermal characterization . . . . . . . . . . . . . . . . . . . . . . . 105
3.4 Nanoindentation results . . . . . . . . . . . . . . . . . . . . . . . . 106
3.5 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
3.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
4. Characterization of Zr55Cu30Al10Ni5 after annealing treatments . . . . . 121
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
4.2 Thermal characterization of Zr55Cu30Al10Ni5 . . . . . . . . . . . . 122
4.3 Microstructural characterization of Zr55Cu30Al10Ni5 . . . . . . . . 124
4.3.1 X-ray diffraction . . . . . . . . . . . . . . . . . . . . . . . . 124
4.3.2 Transmission electron microscopy . . . . . . . . . . . . . . . 126
4.3.3 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
4.4 Mechanical characterization . . . . . . . . . . . . . . . . . . . . . . 135
4.4.1 Compression tests . . . . . . . . . . . . . . . . . . . . . . . 135
4.4.2 Nanoindentation . . . . . . . . . . . . . . . . . . . . . . . . 140
4.4.3 Acoustic measurements of elastic constants . . . . . . . . . 148
4.4.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
4.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
5. Characterization of Zr55Cu30+xAl10Ni5−x (x=-2, 0, 2) . . . . . . . . . . 153
5.1 Thermal characterization . . . . . . . . . . . . . . . . . . . . . . . 153
5.2 Microstructural characterization - Crystallization products . . . . . 157
5.2.1 Introduction - literature review . . . . . . . . . . . . . . . . 157
5.2.2 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
5.2.3 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
5.3 Mechanical and thermo-mechanical characterization . . . . . . . . 178
5.3.1 Viscosity measurements . . . . . . . . . . . . . . . . . . . . 178
5.3.2 Compression tests . . . . . . . . . . . . . . . . . . . . . . . 178
6. Characterization of Zr55Cu30Al10Ni5 after severe deformation . . . . . . 183
6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
6.2 Thermal characterization: DSC . . . . . . . . . . . . . . . . . . . . 186
6.3 Microstructural characterization . . . . . . . . . . . . . . . . . . . 187
6.3.1 X-ray diffraction . . . . . . . . . . . . . . . . . . . . . . . . 187
6.3.2 Transmission electron microscopy . . . . . . . . . . . . . . . 188
CONTENTS vii
6.4 Mechanical characterization - Nanoindentation . . . . . . . . . . . 190
6.4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 190
6.4.2 Experimental conditions nanoindentation . . . . . . . . . . 193
6.4.3 Results and discussion . . . . . . . . . . . . . . . . . . . . . 193
6.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
7. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
7.1 Indentation size effect . . . . . . . . . . . . . . . . . . . . . . . . . 199
7.2 Study of changes on medium range order upon annealing . . . . . 200
7.3 Study of changes on medium range order upon deformation . . . . 201
7.4 Suggestions for future research . . . . . . . . . . . . . . . . . . . . 201
7.5 Articles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
Appendix 221
A. Electron diffraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A
A.1 The reciprocal lattice . . . . . . . . . . . . . . . . . . . . . . . . . . A
A.2 The reflecting sphere . . . . . . . . . . . . . . . . . . . . . . . . . . B
A.3 The structure factor . . . . . . . . . . . . . . . . . . . . . . . . . . C
B. Stereographic projection . . . . . . . . . . . . . . . . . . . . . . . . . . . E
viii CONTENTS