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Review of the Alumina/Ag-Cu-Ti Active Metal Brazing Process [Kõva köide]

  • Formaat: Hardback, 248 pages, kõrgus x laius: 254x178 mm, kaal: 635 g, 52 Tables, black and white; 113 Line drawings, black and white; 398 Halftones, black and white; 511 Illustrations, black and white
  • Ilmumisaeg: 06-Nov-2018
  • Kirjastus: CRC Press
  • ISBN-10: 1138602914
  • ISBN-13: 9781138602915
Teised raamatud teemal:
  • Formaat: Hardback, 248 pages, kõrgus x laius: 254x178 mm, kaal: 635 g, 52 Tables, black and white; 113 Line drawings, black and white; 398 Halftones, black and white; 511 Illustrations, black and white
  • Ilmumisaeg: 06-Nov-2018
  • Kirjastus: CRC Press
  • ISBN-10: 1138602914
  • ISBN-13: 9781138602915
Teised raamatud teemal:

A Review of the Alumina/Ag-Cu-Ti Active Metal Brazing Process is based on the PhD thesis entitled "The Effects of Alumina Purity, Ticusil® Braze Preform Thickness and Post-grinding Heat Treatment, on the Microstructure, Mechanical and Nanomechanical Properties of Alumina-to-Alumina Brazed Joints" which was awarded by Imperial College London’s CASC Steering Group as the 2017 recipient of the Professor Sir Richard Brook Prize (sponsored by Morgan Advanced Materials plc) for Best Ceramics PhD Thesis in the UK. It focusses on the alumina/Ag-Cu-Ti system to cover the active metal brazing of ceramics, variables involved in the process, and the effects of these variables on wetting, interfacial reaction layer formation, and joint strength. The comprehensive review brings together findings from the literature into one place, and presents key concepts in a concise and easy-to-read manner.

Preface ix
Acknowledgements xi
Author xiii
Abbreviations xv
Chapter 1 Introduction
1(6)
1.1 Joining of Alumina
1(1)
1.2 Brazing of Ceramics
1(1)
1.3 Active Metal Brazing of Ceramics
1(1)
1.4 Variables in Active Metal Brazing
2(1)
1.5 The Alumina/Ag-Cu-Ti System
3(1)
1.6 Ceramic-to-Ceramic Joining
3(1)
1.7 Industrial Applications and Market Size
4(3)
Chapter 2 Literature Review
7(60)
2.1 Introduction
7(9)
2.1.1 Reactive Wetting of Alumina Ceramics
7(1)
2.1.2 Ag-Cu-Ti Active Braze Alloys
8(1)
2.1.2.1 Commercially Available Ag-Cu-Ti Braze Alloys
8(1)
2.1.3 Reaction Layer Formation
9(1)
2.1.4 Typical Microstructure
10(1)
2.1.5 Coefficient of Thermal Expansion
11(1)
2.1.6 Role of the Braze Interlayer
12(2)
2.1.7 Joining Mechanism
14(2)
2.2 Variables in the Design of an Ag-Cu-Ti Active Braze Alloy
16(16)
2.2.1 Ag-Cu Concentrations
16(3)
2.2.2 Ti Concentration
19(1)
2.2.2.1 Ag-Cu-Ti Braze Foil Thickness
19(1)
2.2.2.2 Ti Concentration and Wetting
19(3)
2.2.2.3 Ti Concentration and the Reaction Layer
22(9)
2.2.2.4 Ti Concentration and Joint Strength
31(1)
2.3 Process Parameters in Active Metal Brazing
32(15)
2.3.1 Brazing Time
32(1)
2.3.1.1 Brazing Time and Wetting
33(1)
2.3.1.2 Brazing Time and the Reaction Layer
34(2)
2.3.1.3 Brazing Time and Joint Strength
36(2)
2.3.2 Brazing Temperature
38(1)
2.3.2.1 Brazing Temperature and Wetting
39(1)
2.3.2.2 Brazing Temperature and the Reaction Layer
40(4)
2.3.2.3 Brazing Temperature and Joint Strength
44(2)
2.3.3 Brazing Atmosphere
46(1)
2.4 Variables Influencing Ceramic Properties
47(14)
2.4.1 Alumina Purity
47(1)
2.4.1.1 Alumina Purity and Wetting
48(1)
2.4.1.2 Alumina Purity and the Reaction Layer
49(3)
2.4.1.3 Alumina Purity and Joint Strength
52(1)
2.4.2 Alumina Surface Condition
52(3)
2.4.2.1 Surface Roughness
55(3)
2.4.2.2 Grinding and Polishing
58(1)
2.4.2.3 Post-Grinding Heat Treatment
59(2)
2.5 Mechanical Testing
61(3)
2.5.1 Typical Testing Methods
62(2)
2.6 Gaps Identified in the Literature
64(2)
2.6.1 Ag-Cu-Ti Braze Preform Thickness
64(1)
2.6.2 Secondary Phase Interaction
65(1)
2.6.3 Post-Grinding Heat Treatment
65(1)
2.7 Summary of Objectives
66(1)
Chapter 3 Experimental Methods
67(18)
3.1 Alumina Materials Selection and Design
67(1)
3.2 Surface Roughness Measurements
68(1)
3.3 Post-Grinding Heat Treatment
69(2)
3.4 Ag-Cu-Ti Braze Alloy Selection and Design
71(1)
3.5 Brazing Procedure
71(1)
3.6 Mechanical Testing
72(3)
3.7 Macro Images
75(1)
3.8 Mounting and Polishing
75(2)
3.9 Etching Techniques
77(1)
3.10 Optical and Scanning Electron Microscopy
78(1)
3.11 Electron Probe Microanalysis
78(1)
3.12 Focussed Ion Beam Milling
78(3)
3.13 Transmission Electron Microscopy
81(1)
3.14 Nanoindentation
81(1)
3.15 Design of Experiments
82(3)
Chapter 4 Alumina Ceramics
85(24)
4.1 Chemical Composition
85(1)
4.2 Surface Roughness
85(4)
4.3 Microstructure
89(5)
4.3.1 D-96 Alumina
89(3)
4.3.2 D-100 Alumina
92(2)
4.4 Flexural Strength
94(3)
4.4.1 Flexural Strength and Surface Roughness
96(1)
4.5 Post-Grinding Heat Treatment
97(10)
4.6 Conclusions
107(2)
Chapter 5 Microstructural Evolution
109(66)
5.1 As-Received TICUSIL® Braze Foils
109(7)
5.1.1 Cu4Ti3 in TICUSIL® Braze Foil
110(6)
5.2 Microstructures of Brazed Joints in As-Ground Condition
116(21)
5.2.1 50-μm-Thick TICUSIL® Braze Preforms
116(4)
5.2.2 100-μm-Thick TICUSIL® Braze Preforms
120(5)
5.2.2.1 Cu-Ti Phase Formation
125(3)
5.2.2.2 Ag-Rich Braze Outflow
128(1)
5.2.3 150-μm-Thick TICUSIL® Braze Preforms
129(3)
5.2.3.1 Multi-Layered Cu-Ti Structure
132(2)
5.2.4 250-μm-Thick TICUSIL® Braze Preforms
134(3)
5.3 Transmission Electron Microscopy
137(25)
5.3.1 50-μm-Thick TICUSIL® Braze Preforms
137(8)
5.3.2 100-μm-Thick TICUSIL® Braze Preforms
145(8)
5.3.3 Secondary Phase Interaction
153(9)
5.4 Microstructures of Brazed Joints in Ground-and-Heat-Treated Condition
162(10)
5.4.1 D-96 GHT Brazed Joints
162(5)
5.4.2 D-100 GHT Brazed Joints
167(2)
5.4.3 Braze Infiltration
169(3)
5.5 Summary
172(2)
5.6 Conclusions
174(1)
Chapter 6 Joint Performance
175(44)
6.1 Strengths of Brazed Joints in As-Ground Condition
175(13)
6.1.1 50-μm-Thick TICUSIL® Braze Preforms
175(2)
6.1.2 100-μm-Thick TICUSIL® Braze Preforms
177(4)
6.1.3 150-μm-Thick TICUSIL® Braze Preforms
181(3)
6.1.4 Secondary Phase Interaction
184(2)
6.1.5 250-μm-Thick TICUSIL® Braze Preforms
186(2)
6.2 Nanoindentation
188(18)
6.2.1 Calibration
192(3)
6.2.2 Targeted Indents in Alumina
195(1)
6.2.3 Targeted Indents in the Reaction Layer
195(2)
6.2.4 Targeted Indents in the Braze Interlayer
197(4)
6.2.5 Nanohardness Distribution Plots
201(5)
6.3 Strengths of Brazed Joints in Ground-and-Heat-Treated Condition
206(5)
6.3.1 50-μm-Thick TICUSIL® Braze Preforms
206(1)
6.3.2 100-μm-Thick TICUSIL® Braze Preforms
207(4)
6.3.3 150-μm-Thick TICUSIL® Braze Preforms
211(1)
6.4 Summary
211(5)
6.5 Conclusions
216(3)
Appendix 1 Advanced Ceramics Definition 219(2)
Appendix 2 Macro Images of Brazed Joints 221(8)
Appendix 3 Four-Point Bend Testing 229(2)
Appendix 4 Surface Roughness Measurements 231(2)
Appendix 5 Brazing Fixture 233(2)
Nomenclature 235(4)
References 239(6)
Index 245
Following graduation from University College London with an integrated masters (MEng) degree in Engineering with Business Finance in 2009, Tahsin Ali completed a Masters (MRes) degree in the Science and Engineering of Materials at the University of Birmingham in 2010. Thereafter, Tahsin Ali worked in international business development for a leading materials testing manufacturer before commencing a role as a materials development engineer in the hardfacing repair of forging dies. Tahsin Ali qualified as a chartered engineer (CEng) in January 2016 and in October 2017 he completed a doctorate (Ph.D) in the active metal brazing of ceramics at Brunel University London, based full-time at TWI Ltd in Cambridge. In November 2017, Tahsin Ali joined Phillips & Leigh LLP, a firm of patent and trade mark attorneys as a patent scientist and trainee patent attorney specialising in handling inventions in the field of materials science and engineering. This book is based on Tahsins Ph.D thesis entitled "The Effects of Alumina Purity, Ticusil® Braze Preform Thickness, and Post-grinding Heat Treatment, on the Microstructure, Mechanical and Nanomechanical Properties of Alumina-to-Alumina Brazed Joints" which was awarded by Imperial College Londons CASC Steering Group as the 2017 recipient of the Professor Sir Richard Brook Prize (sponsored by Morgan Advanced Materials plc) for Best Ceramics Ph.D Thesis in the U.K. and also received the Deans Prize for Innovation and Impact and the Vice-Chancellors Prize for Doctoral Research at Brunel University London in 2017.