Joining Vacuum High Pressure Die Cast Aluminum Alloy A356

143 Pages·2017·8.85 MB·English

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Electronic Theses and Dissertations Theses, Dissertations, and Major Papers
2013
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Meng Wang
University of Windsor
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Wang, Meng, "Joining Vacuum High Pressure Die Cast Aluminum Alloy A356 Subjected to Heat Treatment
to Wrought Alloy 6061" (2013). Electronic Theses and Dissertations. 4925.
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Joining Vacuum High Pressure Die Cast Aluminum
Alloy A356 Subjected to Heat Treatment to
Wrought Alloy 6061

By

Meng Wang

A Thesis Submitted to the
Faculty of Graduate Studies
through Engineering Materials
in Partial Fulfillment of the Requirements
for the Degree of Master of Applied Science
at the University of Windsor

Windsor, Ontario, Canada
2013
2013 Meng Wang
Joining Vacuum High Pressure Die Cast Aluminum
Alloy A356 Subjected to Heat Treatment to
Wrought Alloy 6061

By Meng Wang

APPROVED BY:

Dr. Henry Hu, Advisor
Department of Mechanical, Automotive and Materials Engineering

Dr. Jerry Sokolowski, Program Reader
Department of Mechanical, Automotive and Materials Engineering

Dr. Behnam Shahrrava, Outside Program Reader
Department of Electrical and Computer Engineering

Dr. Xueyuan Nie, Chair
Department of Mechanical, Automotive and Materials Engineering
August 14, 2013
ii
DECLARATION OF ORIGINALITY
I hereby certify that I am the sole author of this thesis and that no part of this thesis has been
published or submitted for publication.
I certify that, to the best of my knowledge, my thesis does not infringe upon anyone’s copyright
nor violate any proprietary rights and that any ideas, techniques, quotations, or any other material
from the work of other people included in my thesis, published or otherwise, are fully
acknowledged in accordance with the standard referencing practices. Furthermore, to the extent
that I have included copyrighted material that surpasses the bounds of fair dealing within the
meaning of the Canada Copyright Act, I certify that I have obtained a written permission from
the copyright owner(s) to include such material(s) in my thesis and have included copies of such
copyright clearances to my appendix.
I declare that this is a true copy of my thesis, including any final revisions, as approved by my
thesis committee and the Graduate Studies office, and that this thesis has not been submitted for
a higher degree to any other University or Institution.

i
ABSTRACT
The objective of the present work was to investigate the feasibility of joining high pressure
die cast aluminum alloy A356 for automotive applications. Joining of vacuum high pressure die
cast aluminum alloy A356 subjected to different heat treatments with wrought 6061 was carried
out by using the Gas Metal Arc Welding (GMAW) process. The results of tensile testing showed
that the order of the welded samples with the overall engineering performance combining the
strengths and ductility from the highest to the lowest were T5-A356 alloy, as-cast A356 alloy,
T6-A356 alloy and T4-A356 alloy. The SEM microstructure analysis indicated the high level of
porosity present in heat treated alloys should be responsible for the failure of the filler alloy. The
fractographic analyses revealed that the 6061 samples exhibited the highest ductility among the
tested alloys, which were consistent with the results of tensile testing.

ii
DEDICATION
I dedicate this thesis to my parents and grandmother. Their love, support and encouragement
during my study at University of Windsor has become part of my strength, and enabled me
through those difficulties and finally completed this work.

iii
ACKNOWLEDGEMENTS
First of all, I would like to express my sincere gratitude to my supervisor, Dr. Henry Hu, for kind
suggestion, excellent guidance and providing me the greatest opportunity to join the engineering
group in University of Windsor.
Many thanks to the program reader, Dr. Sokolowski and the outside program reader, Dr. Behnam
for taking time on my thesis presentation and great suggestion given to this project.
I am very grateful to the university department technicians, Mr. Andy Jenner for helping me
machine tensile samples, and Mr. Gang Li’s help of SEM training and sample preparation for the
microstructure analysis, and also to the classmates in my group, Xuezhi Zhang and Yanda Zou,
for their great help on the experiment and valuable discussion for the research work.
Great thanks to Mr Patrick Cheng (Ryobi Die Casting, USA), for supplying materials and
conducting mechanical tensile tests, and Mr Gary Meng (AGS Agreatsun Welding, Mississauga),
for technically welding samples.
Most of all, I would like to express my deepest gratitude to my family, especially my parents for
the love, encouragement and support they place in me.

iv
TABLE OF CONTENTS

DECLARATION OF ORIGINALITY ..................................................................................... i
ABSTRACT.............................................................................................................................. ii
DEDICATION ........................................................................................................................ iii
ACKNOWLEDGEMENTS .................................................................................................... iv
LIST OF TABLES .................................................................................................................. ix
LIST OF FIGURES ..................................................................................................................x
CHAPTER 1 INTRODUCTION ...........................................................................................1
1.1. Background .....................................................................................................................1
1.2. Motivation .......................................................................................................................2
1.3. Objective & Tasks ...........................................................................................................3
1.4. Thesis Layout ..................................................................................................................4
CHAPTER 2 LITERATURE REVIEW................................................................................5
2.1. Introduction ....................................................................................................................5
2.1.1. Classification of Aluminum Alloys ..........................................................................6
2.1.2. Definitions of Welding ............................................................................................8
2.2. Welding Design and Processes........................................................................................9
2.2.1. Welding Safety ........................................................................................................9
2.2.2. Description of Fusion Welding Processes .............................................................. 10
2.2.3. Inert Shielding Gases ............................................................................................. 11
2.2.4. Filler Metal Selection ............................................................................................ 11
2.3. TIG welding .................................................................................................................. 12
2.3.1. Introduction to GTAW Welding ............................................................................ 12
2.3.2. Process Principles .................................................................................................. 13
v
2.3.3. Shielding Gas Selection ......................................................................................... 15
2.4. MIG welding ................................................................................................................. 17
2.4.1 Definition ............................................................................................................... 17
2.4.2 Process Principles ................................................................................................... 18
2.4.3 Shielding Gas Selection .......................................................................................... 19
2.5. Mig and Tig comparision .............................................................................................. 23
2.5.1 Process Difference .................................................................................................. 23
2.5.2 Advantages and Disadvantages ............................................................................... 24
2.6. Other Welding Processes .............................................................................................. 25
2.6.1 Introduction ............................................................................................................ 25
2.6.2 Plasma-arc Welding................................................................................................ 25
2.6.3 Laser Welding ........................................................................................................ 25
2.6.4 Electron Beam Welding .......................................................................................... 27
2.7. Filler metal (alloy) selection criteria ............................................................................ 27
2.7.1 Introduction ............................................................................................................ 27
2.7.2 Primary Factors ...................................................................................................... 28
2.7.3 Types for Filler Metals ........................................................................................... 28
2.8. Detect prevention .......................................................................................................... 29
2.8.1 Oxide ..................................................................................................................... 29
2.8.2 Hydrogen Solubility ............................................................................................... 30
2.8.3 Electrical Conductivity ........................................................................................... 30
2.8.4 Thermal Characteristics .......................................................................................... 30
2.8.5 Forms of Aluminium .............................................................................................. 30
2.9. Solution Treatment Work on 3XX Serial Alloys ......................................................... 31
2.9.1 Morphology of Silicon Phase during Solution Treatment ........................................ 31
vi
2.9.2 Effect of Porosity Influence on Mechanical Properties ............................................ 43
2.10. Summary ..................................................................................................................... 45
CHAPTER 3 EXPERIMENTAL PROCEDURES ............................................................. 46
3.1. Materials ....................................................................................................................... 46
3.2. Gas Metal Arc Welding (GMAW) ............................................................................... 47
3.3. Tensile Testing .............................................................................................................. 49
3.3.1. Specimens Preparation........................................................................................... 49
3.3.2. Tensile Test ........................................................................................................... 51
3.4. Microstructural Analysis .............................................................................................. 52
3.4.1. Specimens Preparation........................................................................................... 52
3.4.2. Metallographic Analysis ........................................................................................ 53
CHAPTER 4 RESULTS AND DISCUSSION ................................................................... 56
4.1. Tensile Properties ......................................................................................................... 56
4.1.1. Based Alloys and Filler Metal (ER 4043) .............................................................. 56
4.1.1.1. 6061 Wrought Alloy ....................................................................................... 56
4.1.1.2. As- Cast Alloy A356 ....................................................................................... 58
4.1.1.3. T4 Cast Alloy A356 ........................................................................................ 59
4.1.1.4. T5 Cast Alloy A356 ........................................................................................ 61
4.1.1.5. T6 Cast Alloy A356 ........................................................................................ 62
4.1.1.6. Filler Metal (ER 4043) .................................................................................... 64
4.1.2 Joined Cast alloys A356 with Wrought alloy 6061 ................................................ 64
4.1.2.1. As-cast A356& 6061 Wrought Alloy .............................................................. 65
4.1.2.2. T4 A356& 6061 Wrought Alloy ...................................................................... 66
4.1.2.3. T5 A356& 6061 Wrought Alloy ...................................................................... 67
4.1.2.4. T6 A356& 6061 Wrought Alloy ...................................................................... 68
vii