Shopt-peening and low-cycle fatigue of titanium alloys

229 Pages·2015·17.52 MB·English

by  Yugang Li

Thèse
de doctorat

de l’UTT
Yugang LI
Shot-peening and Low-cycle Fatigue
of Titanium Alloys: Instrumented
Indentation and X-ray Diffraction

Spécialité :
Systèmes Mécaniques et Matériaux

2015TROY0031 Année 2015
THESE

pour l’obtention du grade de

D de l’U
OCTEUR NIVERSITE

T T
DE ECHNOLOGIE DE ROYES

Spécialité : SYSTEMES MECANIQUES ET MATERIAUX

présentée et soutenue par

Yugang LI

le 13 novembre 2015

Shot-peening and Low-cycle Fatigue of Titanium Alloys:
Instrumented Indentation and X-ray Diffraction

JURY

Mme C. LANGLADE PROFESSEUR DES UNIVERSITES Président
M. M. FRANCOIS PROFESSEUR DES UNIVERSITES Directeur de thèse
Mme P. KANOUTÉ INGENIEUR DE RECHERCHE ONERA Directrice de thèse
M. A. KORSUNSKY PROFESSOR Examinateur
Mme C. MABRU PROFESSEUR DES UNIVERSITES Rapporteur
M. H. PELLETIER PROFESSEUR DES UNIVERSITES Rapporteur

To my wife Cunfeng
To my parents and my elder sister

“I never saw a wild thing sorry for itself. A small bird will drop frozen dead from a bough
without ever having felt sorry for itself.”

- D.H. Lawrence

Acknowledgements

How time flies. Four years have passed so fast, like a shuttle traveling on the loom. But, these
four years are not poems written in water. With the assistances of many people, finally, I
finished my doctoral dissertation.
First and foremost, I would like to show my sincere appreciation to my supervisors, Prof.
Manuel François and Dr. Pascale Kanouté, for their support and guidance throughout my Ph.D
study. Manuel leaded me into the gate of scientific research, taught me many skills and lots of
knowledge in materials sciences and engineering, and greatly broadened my horizon. Pascale
showed me profound sensibleness on fatigue of metallic materials. Things they passed on to
me will definitely become the steady basis of my researching career in the future.
Authentic gratitude will also be expressed to Prof. Pelletier Hervé and Prof. Mabru
Catherine for their valuable comments on my thesis, and to Prof. Langlade Cécile and Prof.
Korsunsky Alexander for serving as juries in my Ph.D defense committee. Their kind help and
frank advices greatly improved the quality of my thesis. I would like to show my special thanks
to Mr. Virgil Optasanu, who helped me a lot on the heat treatment of T40, and Ms. Anne
Lepied, who supplied us with the bulk of Ti-18 alloy.
Many colleagues in U.T.T, who gave me lots of help in technical support, experimental
experiences, specimen preparation, problem discussion, etc., are absolutely worthy of my
cordial acknowledgement. They are Mr. Bruno Guelorget, Mr. Laurent Daniel, Mr. Bruno
Lesage, Prof. Xiaolu Gong, Prof. Zhidan Sun, Prof. Delphine Retraint, Mr. François Weil, Mr.
Donato Gallitelli and Mr. Abdellah Oukkir. Without their assistance I could not have finished
my Ph.D work so fluently.
I would like to sincerely appreciate my friends as well. Hongchang Han, Qiong Li, Yingjun
Deng, Hui Shang, Xiaowei Lv, Mengyi Zhang and Haibin Zhu helped me a lot in my daily life.
Without the help of Fanjuan Meng, Song Chen, Jie Zhang, Huan Wang, Wenjin Zhu, Tian
Wang, Jian Zhang, I could not adapt to the life in Troyes so quickly and so well. Kun Jia, Xuan
Zhou aided me a lot in experiments. Zhongmeng Wen, Jianqiang Zhou, Weijie liu, Zhenming
Yue, Yosr Ghozzi enlightened me from several aspects for numerical simulations. Von Dim
Nguyen helped me a lot about the usage of modeFRONTIER.
Last but not least, I would like to show my most sincere appreciation and deepest love to
my wife, my parents and my elder sister. It is them who rose me up to more than I can be. Their
altruistic love is always the strongest support of my life. I’m so proud of loving and being
loved by them.

Yugang Li

Sep. 2015, at Troyes

Notations................................................................................................................................................. I
Abbreviations ...................................................................................................................................... III
List of figures ...................................................................................................................................... IV
List of tables ......................................................................................................................................... X
Abstract ............................................................................................................................................... XI
Résumé .............................................................................................................................................. XII
General introduction ............................................................................................................................ 1
Chapter 1 ............................................................................................................................................... 4
Background and research status ......................................................................................................... 4
1.1 Basic concepts concerned ............................................................................................................. 5
1.1.1 Shot-peening .......................................................................................................................... 5
1.1.2 Residual stress ....................................................................................................................... 6
1.1.3 Work hardening ..................................................................................................................... 8
1.1.4 Fatigue failure in metallic materials ...................................................................................... 9
1.2 The influence of RS and WH on fatigue process ....................................................................... 10
1.2.1 The influence of residual stress ........................................................................................... 10
1.2.2 The influences of work hardening ....................................................................................... 11
1.3 Evolution of RS and WH during fatigue process ....................................................................... 12
1.3.1 Cyclic relaxation of residual stress ...................................................................................... 12
1.3.2 Cyclic relaxation of mean stress .......................................................................................... 13
1.3.3 Cyclic evolution of work hardening .................................................................................... 16
1.4 Characterization of residual stress .............................................................................................. 17
1.4.1 Relaxation measurement methods ....................................................................................... 17
1.4.2 Diffraction methods ............................................................................................................. 18
1.4.2.1 Geometrical definition of X-ray diffraction system ..................................................... 19
1.4.2.2 Standard sin2Ψ method ................................................................................................. 20
1.4.3 Instrumented indentation methods....................................................................................... 22
1.5 Characterization of Work Hardening ......................................................................................... 26
1.5.1 Hardness indentation ........................................................................................................... 26
1.5.2 Electron backscatter diffraction (EBSD) ............................................................................. 26
1.5.3 X-ray diffraction .................................................................................................................. 28
1.6 Titanium and its alloys ............................................................................................................... 29
1.6.1 Crystal structure................................................................................................................... 29