稀土永磁合金高温相变 原位动态观察及在材料设计中的应用 英文【2025|PDF|Epub|mobi|kindle电子书版本百度云盘下载】

稀土永磁合金高温相变 原位动态观察及在材料设计中的应用 英文PDF格式电子书版下载

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Chapter 1 Introduction1

1.1 Rare EarthPermanent-magnetAlloys2

1.1.1 Rare earth2

1.1.2 Classification and development of rare earth permanent-magnet alloys2

1.1.3 Crystal structure of rare earth permanent-magnet alloys4

1.1.4 Magnetic parameters of rare earth permanent-magnet alloys7

1.1.5 Criterion of permanent-magnet alloys(materials)8

1.2 Principle for Alloy Phase and Phase Transformation and Growth Rule of New Phase8

1.2.1 Phase9

1.2.2 Phase transformation9

1.2.3 Alloy9

1.2.4 Material10

1.2.5 Alloy phase10

1.2.6 Solid solution10

1.2.7 Exsolution precipitation10

1.2.8 Thermodynamic bases for phase transformation and classification10

1.2.9 Single crystal17

1.2.10 Single crystal superalloy17

1.2.11 Enthalpy18

1.2.12 Entropy18

1.2.13 Latent heat of phase transformation19

1.2.14 Driving force of phase transformation19

1.2.15 Rule of growing up of new phase20

1.3 Research Methods of the Magnetic Properties of Rare Earth Permanent Magnets21

Reterences25

Chapter 2 The First Generation Rare Earth Permanent-magnet Alloys27

2.1 High temperature Phase Transition and Magnetic Properties of SmCo5 Permanent-magnet Alloys28

2.2 The in Situ and Dynamic Observation on High Temperature Phase Transformation of SmCo5 Permanent Magnetic Alloyat 25-750℃35

2.2.1 Magnetic measurement36

2.2.2 Sample preparation and experiment method38

2.2.3 Influence of annealing treated specimen on coercivity39

2.2.4 The in situ and dynamic observation by 1000kV HVEM under heating condition41

2.2.5 Discussion50

2.3 Magnetism and the in Situ and Dynamic Observation of Permanent MagneticAlloy of SmCo5 byAnnealing at 600-1000℃54

2.3.1 Specimen preparation and experimental method55

2.3.2 Analysis on chemical composition of the SmCo5 permanent magnetic alloy55

2.3.3 Magnetic measurement55

2.3.4 Structure of magnetic domain56

2.3.5 Irreversible loss of SmCo5 permanent magnetic alloy after annealing at 25-1000℃57

2.3.6 Electronic energy spectrum experiment and analysis of SmCos permanent magnetic alloy58

2.3.7 The in situ and dynamic observation on eutectoid decomposition of SmCo5 by electronic microscope61

2.3.8 The in situ and dynamic observation of SmCo5 in thermal state using transmission electronic microscope62

2.3.9 The in situ and dynamic observation on SmCo5 in thermal condition of 750-960℃ by Transmission Electronic Microscope63

2.3.10 Discussion65

2.3.11 Conclusions67

2.4 Analysis on Variation ofthe Coercivity and Phase Transformation68

2.4.1 Specimen preparation and experimental method68

2.4.2 Experimental result and discussion69

2.4.3 Conclusions74

2.5 The Optic-electronic Spectrum Study on SmCo5 Permanent MagneticAlloy74

2.5.1 Specimen preparation technique and experimental condition of optic-electronic energy spectrum75

2.5.2 Investigation on surface composition of SmCo575

2.5.3 Atoms concentration variation of elements of samarium,cobalt and oxygen from surface to depth76

2.5.4 Surface compound77

2.5.5 Conclusions77

2.6 Analysis on Magnetic Hysteresis Loop of SmCo5 Permanent MagneticAlloy77

2.6.1 Specimen preparation technique,magnetic measurement and transmission microscope condition and experimental method78

2.6.2 Analysis on chemical composition of three kinds of specimens78

2.6.3 Analysis on preparation technique80

2.6 4 Curve of magnetic performance and analysis at 77-550K80

2.6.5 Observation and analysis on specimen using TEM81

2.6.6 Conclusions82

2.7 Magnetism of SmCo5 Permanent Alloy at 1.5-523K82

2.7.1 Specimen preparation technique,magnetic measurement apparatus and experimental method82

2.7.2 Magnetism measurement and curve of SmCo5 permanent magnetic alloy at 1.5K and 40K83

2.7.3 Measurement of demagnetization curve and value of magnetic parameter at-196-250℃ by magnetic parameter measurement apparatus85

2.7.4 Reversible temperature coefficient of SmCo5 at-196-250℃87

2.7.5 Coercivity of SmCo5 at 475-1000℃87

2.7.6 Discussion89

2.7.7 Conclusions90

References90

Chapter 3 The Second Generation Rare Earth Permanent-magnet Alloys95

3.1 Phase Precipitation,Phase Transformation at High Temperature and Magnetism of High Coercivity Sm(Co,Cu,Fe,Zr)7.496

3.1.1 Specimen preparation process and experimental method97

3.1.2 Results of specimen magnetic measurement98

3.1.3 Microtexture of the alloy at room temperature99

3.1.4 The in situ and dynamic observation on precipitation,growth up and high temperature phase transformation of cellular structure from room temperature to high temperature101

3.1.5 Conclusions116

3.2 Function of Zirconium on Sm(Co,Cu,Fe,Zr)7.4 Permanent Magnetic Alloy＆Observation and Analysis by Electron Microscope118

3.2.1 Specimen preparation and experimental method118

3.2.2 Research on function of Zirconium118

3.2.3 Conclusions121

3.3 Magnetism of High Coercivity Sm(Co,Cu,Fe,M)7 4Permanent Magnetic Alloy at 1.5-523K121

3.3.1 Preparation of specimen and magnetism measurement apparatusz and measurement method122

3.3.2 Measurement results and discussion122

3.3.3 Conclusions125

References126

Chapter 4 The Third Generation Rare Earth Permanent Magnet129

4.1 Improvement of the Properties of NdFeB Permanent Magnets Due to Element Substitutions129

4.2 Magnetic Properties and the Occupancy of Co and Ga Atoms for NdFe(Co,Al,Ga)B Permanent-Magnetic Alloys133

4.2.1 Preparation and method133

4.2.2 Nd16Fe77-xCoxB7 alloy134

4.2.3 Nd16Co10Fe67-yAlyB7 and Nd16Co16Fe61-yAlyB7 alloys136

4.2.4 Nd16Co16Fe61-xGaxB7 alloy138

4.2.5 Conclusions144

4.3 The Studies of Main Phase Nd2Fe14B and Nd2(Fe,Co)14B in NdFeB Permanent-magnet Alloys145

4.3.1 The preparation of samples and experimental methods145

4.3.2 SEM analysis145

4.3.3 The formation of Nd2Fe14B146

4.3.4 M？ssbauer spectra at room temperature146

4.3.5 Composition analysis and the studies of M？ssbauer spectra for Nd2(Fe,Co)14B147

4.3.6 In situ and dynamic observation of TEM on Nd2Fe14B and Nd2(Fe,Co)14B147

4.3.7 Conclusions150

4.4 Studies on B-rich Phase in NdFeB Alloy150

4.4.1 Preparation process and experimental method151

4.4.2 The in situ and dynamic observation of Nd1.11Fe4B4 by TEM151

4.4.3 Study on Nd1+εFe4B4 by X-Ray diffraction and M？ssbauer effect153

4.4.4 Analysis on Nd1.1Fe4B4 phase153

4.4.5 Relationship between B-rich phase and coercivity155

4.4.6 Conclusions156

4.5 Influence ofBoron Content in NdFeB on Nd2Fe14B Phase and Magnetic Property156

4.5.1 Specimen preparation process and experimental method157

4.5.2 Influence of boron content on alloy magnetic property and phase structure157

4.5.3 Conclusions161

4.6 High Curie Temperature NdFeCoGaB Permanent Magnetic Alloy162

4.6.1 Preparation process and experiment method162

4.6.2 Using cobalt to replace part of iron163

4.6.3 Use Ga to replace part of iron in NdFeCoB alloy163

4.6.4 Conclusions168

4.7 Influence of Adding Element Dysprosium on Performance of NdFeB Alloy168

4.7.1 Specimen preparation process and experimental method169

4.7.2 Experiment result using SEM169

4.7.3 Measurement of magnetism170

4.7.4 Experiment result using transmission microscope171

4.7.5 Distribution of Dy2O3171

4.7.6 Conclusions174

4.8 Nanocrystalline Microstructure and Coercivity Mechanism Model of NdFeB Alloys with Nb and Ga174

4.8.1 Experimental procedure175

4.8.2 Magnetic properties measuring175

4.8.3 Study of M？ssbauer effect176

4.8.4 Study of nano-microstructure of NdFeB alloys with Nb178

4.8.5 Dynamic cross and microstructure of the NdFeB alloys with Nb and Dy178

4.8.6 Dynamic cross and microstructure of the NdFeB alloys with Nb,Ga,Co and Dy179

4.8.7 Curie temperature of the NdFeB alloys with Nb180

4.8.8 New coercivity mechanism model of multi-component NdFeB alloys182

4.8.9 Conclusions183

4.9 In Situ and Dynamic Observation on Magnetic and Phase Transformation of Nd15Fe78B7 Permanent Magnet at High Temperature184

4.9.1 Preparation process of specimen and experiment method185

4.9.2 Microstructure and phase in crystal boundary of NdFeB permanent magnet185

4.9.3 Phase transformation of microstructure of B-rich phase at high temperature189

4.9.4 Phase transformation of microstructure of Nd-rich filmy belt in Nd15Fe78B7 crystal boundary at high temperature190

4.9.5 Phase transformation of Nd2Fe14B base phase of Nd15Fe78B7 alloy at high temperature193

4.9.6 Conclusions194

4.10 In Situ and Dynamic Observation on High Temperature Phase Transformation and Magnetism of Nd16Fe77B7 Permanent Magnetic Alloy195

4.10.1 Samples preparationprocess and experimental method196

4.10.2 The in situ and dynamic observation on nanometer microstructure and high temperature phase transformation196

4.10.3 Function of cobalt in NdFeCoB alloy201

4.10.4 Magnetic characteristic measurement result and analysis201

4.10.5 Curie temperature measurement result202

4.10.6 Phase analysis by X-ray diffraction,lattice constant and cell volume202

4.10.7 Relationship between aging temperature and coercivity of Nd16Fe69Co8B7203

4.10.8 Conclusions204

4.11 Analysis on Lamella Phase of Grain Boundary in Microstructure of NdFeB Permanent Magnetic Alloy204

4.11.1 Experimental method204

4.11.2 Magnetism measurement205

4.11.3 Analysis on result of the in situ and dynamic observation of samples205

4.12 Quick Quenched NdFeB Permanent Magnetic Alloy215

4.12.1 Sample preparation technique and experimental method215

4.12.2 Measurement result of quick quenched magnet215

4.12.3 Relationship between crystallization temperature and coercivity216

4.12.4 Microstructure at room temperature216

4.12.5 The in situ and dynamic observation on the non-crystal sample transferring to micro-crystal by HVEM216

4.12.6 Conclusions217

4.13 Stability of the Rare Earth Permanent Magnetic Alloy217

4.13.1 Stability on temperature217

4.13.2 Time stability224

4.13.3 Chemical stability224

4.13.4 Conclusions224

References225

Chapter 5 Developments and Prospect of the Rare Earth Permanent-magnet Alloys231

5.1 Overseas General Development232

5.2 Domestic General Development238

5.3 Development Survey of Preparation Technology243

5.4 Application and Expectation248

References253

Appendix257

Appendix 1 The Structure of Outer Electrons for Rare Earths257

Appendix 2 Atomic and Ionic Radius of Rare Earths258

Appendix 3 Physical Properties of Rare Earths259

Appendix 4 Fundamental Physical Constants261

Appendix 5 Conversion of magnetic quantity between SI and Gaussian units262

Index265