Synthesis, Properties, and Applications of 3D hBN/graphene Reinforced CuNi Composites
- Issued Date
- 2022
- Abstract
- 그래핀또는hBN의3차원적으로상호연결된네트워크는금속메트릭스복합체의 기계적, 열적 및 화학적 특성을 향상시키는 유망한 구조가 될 수 있다. 본 논문에서는 그래핀과 hBN 네트워크로 강화된 Cu0.7Ni0.3 복합 재료를 제작하기 위해 간단한 2단계 공정을 사용했다. 간단한 2단계 공정에는 마이크로 크기의 Cu 및 Ni 입자 혼합물을 압축 성형과 화학 기상 증착 (CVD)이 포함된다. hBN 강화 CuNi (3Di-hBN CuNi) 복합체는 데카보레인 (Decaborane) 및 암모니아 (NH3) 전구체를 사용하여 제작된 반면 그래핀 강화 CuNi (3DiGr CuNi) 복합체는 메탄을 전구체로 사용하여 제작하였다. 광학 현미경, 주사 전자 현미경, 투과 전자 현미경 및 X-선 회절 분석과 같은 다양한 특성 평가 기술을 사용하여 그래핀 또는 hBN 층이 CuNi 입자를 둘러싸고 있어 복합체에 흥미로운 속성을 부여하는 것을 확인하였다. 단축 인장 시험은 3Di-hBN이 CVD 공정을 제외하였을 때 동일한 조건에서 제조된 PM CuNi 합금에 비해 3Di-hBN CuNi 복합체가 항복강도 및 최대 인장 강도, 파괴 인성이 각 ∼16.3%, ∼11.67% 및 ∼27.9%이 향상되어 기계적 특성에 긍정적인 영향을 미치는 것으로 나타났다. 3Di-hBN CuNi 복합체의 전체적인 기계적 성능의 향상은 Cu-Ni 입자의 계면에서 3Di-hBN 층이 형성되어 복합체가 하중을 전달하고, 전위 강화, 입자 미세화 메커니즘을 통해 가해진 하중을 견딜 수 있게 된 것이다. 전기화학적 특성은 otentiodynamic polarization과 전기 임피던스분광법으로조사하였고,열적특성은열중량분석과고온산화실험으로 조사하였다.그결과전기화학적전위차부식실험중3Di-hBN CuNi복합체가PM CuNi합금(hBN미포함)보다6배높은내식성을보였다.또한, 900°C에서수행된고온산화 실험에서 3Di-hBN CuNi 복합체가 PM CuNi 합금에 비해 중량이 ∼36% 작게 증가하였으며,이는고온산화에대한저항성이더우수함을나타낸다.그리고3Di-hBN CuNi 복합체의열전도율은PM CuNi합금보다∼10%더높은것으로확인하였다. 3Di-hBN CuNi 및 3DiGr CuNi 복합체의 향상된 화학적 및 열적 안정성은 hBN과 그래핀의 불투과성 및 열 안정성, 즉 고온에서 원자, 이온 또는 분자의 침투/확산을 차단할 수 있는 능력 때문이다.마찬가지로, 3DiGr CuNi도PM CuNi합금보다58%더높은열전도율, ∼25.9% 항복 강도를 보였다. 3DiGr CuNi의 개선된 특성은 3차원의 그래핀 네트워크가 전자 이동성을 위한 전도 경로 채널을 제공하고, 외부에서 가해지는 부하에 대한 전위 이동을 차단하는 기능과 관련이 있는 것으로 보인다.| Three dimensionally interconnected network of graphene or hBN can be a promising structure to improve the mechanical, thermal, and chemical properties of metal matrix composites. In this dissertation, a simple two-step process was used to fabricate Cu0.7Ni0.3 composites reinforced by such networks of graphene or hBN. A simple twostep process involves the compaction of micronsized Cu (70wt.%) and Ni (30wt.%) particles followed by chemical vapor deposition (CVD). hBN reinforced CuNi (3Di-hBN CuNi) composite was fabricated using the decaborane and ammonia precursors whereas graphene reinforced CuNi (3DiGr CuNi) composite was fabricated using the methane as precursor. By using various characterization techniques such as optical microscopy, scanning electron microscopy, transmission electron microscopy, and X-ray diffraction analysis, it was shown that graphene or hBN layers surround the CuNi grains and thus impart interesting attributes to the composite.
Uniaxial tensile investigations showed that 3Di-hBN positively influenced the mechanical properties of 3Di-hBN CuNi composite; ∼16.3%, ∼ 11.67%, and ∼ 27.9% higher yield strength, UTS, and fracture toughness, respectively, compared to PM CuNi alloy which was prepared under similar conditions except MOCVD. The overall improved mechanical performance of 3Di-hBN CuNi composite was attributed to the formation of 3Di-hBN layers at the interfaces of Cu-Ni grains, which enable the composite to withstand the applied load through the mechanisms of load transfer, dislocation strengthening, and grain refinement. The lectrochemical performance was examined by potentiodynamic polarization and electrical impedance spectroscopy while thermal performance was investigated by thermal gravimetric analysis and hightemperature oxidation experiment. The results indicated that 3Di-hBN CuNi composite displayed 6 times higher corrosion resistance than PM CuNi alloy (without hBN) during the electrochemical potentiodynamic corrosion experiments. Furthermore, hightemperature oxidation experiment performed at 900 °C revealed that 3DihBN CuNi composite gained ∼36% less weight compared to PM CuNi alloy indicating its better resistance to high-temperature oxidation. In addition, thermal conductivity of 3Di-hBN CuNi composite was found ∼10% higher than that of PM CuNi alloy. The improved chemical and thermal stabilities of 3Di-hBN CuNi and 3DiGr CuNi composites can be attributed to the impermeability and thermal stability of hBN/graphene, i.e. its ability to block the penetration/diffusion of atoms, ions or molecules at high temperatures. Similarly, 3DiGr CuNi also showed 58% higher thermal conductivity, ∼25.9% yeild strength than PM CuNi alloy. The improved roperties were associated with the ability of 3D graphene network of providing conducting path channels for electron mobility and blocking the dislocation motion against the externally applied load.
- Alternative Title
- 3차원 그래핀/육방정 질화붕소로 강화된 CuNi 복합체의 합성과 특성 그리고 응용
- Alternative Author(s)
- Zahid Hussain
- Affiliation
- 조선대학교 일반대학원
- Department
- 일반대학원 첨단소재공학과
- Advisor
- 최병상
- Awarded Date
- 2022-02
- Table Of Contents
- LIST OF ABBREVIATIONS AND ACRONYMS v
LIST OF FIGURES vi
LIST OF TABLES xiii
ABSTRACT xiv
한 글 요 약 xvi
1 INTRODUCTION 1
1.1 Contributions 3
1.2 Thesis Organization 5
2 BACKGROUND 6
2.1 Two-dimensional (2D) Materials 6
2.1.1 Hexagonal Boron Nitride 7
2.1.2 Graphene 9
2.2 2D Materials Metal Matrix Composites 12
2.3 Current Challenges for Fabricating 2D Materials MMCs 13
2.4 Fabrication Methods 14
2.4.1 Mechanical Alloying (MA) 14
2.4.2 Semi Powder Metallurgy (SPM) 15
2.4.3 Molecular-level Mixing (MLM) 16
2.4.4 Electrochemical deposition (ELD) 18
2.4.5 In-situ Growth 20
2.4.5.1 Process Chemistry of In Situ Growth via CVD (or MOCVD) 22
2.5 Applications of Gr/hBN MMCs 26
2.5.1 Mechanical Properties 26
2.5.1.1 Load Transfer 26
2.5.1.2 Dislocation Strengthening 29
2.5.1.3 Grain refinement 29
2.5.2 Thermal properties 29
2.5.3 Corrosion Properties 30
2.6 Summary 31
3 EXPERIMENTAL 32
3.1 Research Objectives 32
3.2 Fabrication of 3Di-hBN CuNi Composite 32
3.2.1 Compaction of CuNi powders 32
3.2.2 Metal Organic Chemical Vapor Deposition (MOCVD) 35
3.3 Fabrication of 3DiGr-CuNi Composite 36
3.3.1 Compaction of CuNi Particles 36
3.3.2 Chemical Vapor Deposition (CVD) 36
3.4 Characterization of Synthesized Composites 38
3.4.1 Density of Composite 38
3.4.2 Microstructural Characterization 40
3.4.2.1 Optical Microscopy (OM) 40
3.4.2.2 Scanning Electron Microscopy (SEM) 40
3.4.2.3 Transmission Electron Microscopy (TEM) 40
3.4.2.4 X-ray Diffraction (XRD) 41
3.4.3 Electrochemical Corrosion Experiments 42
3.4.4 High-Temperature Oxidation 43
3.4.5 Uniaxial Tensile Tests 44
3.4.6 Thermal Conductivity Measurement 44
4 RESULTS AND DISCUSSIONS 46
4.1 Synthesis of 3Di-hBN CuNi composites 46
4.1.1 Mechanism of hBN Formation at Grain Boundaries 46
4.1.2 Optimal Conditions for Forming 3Di-hBN 47
4.1.3 Microstructural Investigation 50
4.2 Properties of 3Di-hBN CuNi composites 54
4.2.1 Mechanical Properties 54
4.2.2 Thermal Conductivity Analysis 60
4.2.3 Electrochemical Corrosion Behavior 62
4.2.4 High-Temperature Oxidation Behavior 67
4.3 Synthesis of 3DiGr CuNi Composites 70
4.3.1 Mechanism of Formation of 3DiGr 70
4.3.2 Microstructural Investigation 71
4.4 Properties of 3DiGr CuNi Composites 76
4.4.1 Thermal Conductivity 76
4.4.2 Electrochemical Corrosion Behavior 77
4.4.3 Tensile Strength 79
5 CONCLUSIONS AND FUTURE SCOPE 80
5.1 Conclusions 80
5.1.1 3Di-hBN CuNi Composite 80
5.1.2 3DiGr CuNi Composite 81
5.2 Future Scope 82
PUBLICATIONS 84
BIBLIOGRAPHY 85
APPENDIX A: Main Reagents and Materials 108
APPENDIX B: Synthesis and Characterization Tools 109
B.1 CVD System 109
B.2 Other Experimental Instruments 109
B.3 Characterization Methods 109
APPENDIX C: Sample Preparation for Microstructural Investigation 111
C.1 Sample Preparation for OM 111
C.2 Etchant Preparation 111
C.3 Sample Preparation for SEM 112
C.4 Freeze-Drying Method 112
C.5 Sample Preparation for TEM 112
APPENDIX D: Properties Measurement 114
D.1 Mechanical Properties 114
D.2 Heat Capacity Measurement with DSC Q2000 114
APPENDIX E: Links to Rights and Permissions 117
- Degree
- Doctor
- Publisher
- 조선대학교 대학원
- Citation
- 후세인 자히드. (2022). Synthesis, Properties, and Applications of 3D hBN/graphene Reinforced CuNi Composites.
- Type
- Dissertation
- URI
- https://oak.chosun.ac.kr/handle/2020.oak/17187
http://chosun.dcollection.net/common/orgView/200000590537
- Appears in Collections:
- General Graduate School > 4. Theses(Ph.D)
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