표제지
목차
國文要略 17
Ⅰ. 서론 18
1.1. 연구 배경 18
1.2. 연구 목표 28
Ⅱ. 이론적 배경 30
2.1. 전자파 이론 30
2.1.1. 전자파 30
2.1.2. 전자파 차폐 32
2.1.3. 전자파 차폐효과 이론 35
2.1.4. 전자파 차폐 규격 48
2.2. 복합재 이론 52
2.2.1. 복합재 정의 52
2.2.2. 복합재 이론 54
2.2.3. 적층복합재의 역학이론 60
2.3. 탄소소재 및 성형 62
2.3.1. NCF(Non-Crimped Fabric) 탄소섬유 62
2.3.2. GNPs(Graphene Nanoplatelets) 68
2.3.3. 탄소소재의 성형법 70
Ⅲ. 복합재 제조 76
3.1. 시험편 재료 76
3.2. 탄소나노강화 기지재의 분산성과 점성 특성 분석 79
3.2.1. 온도에 따른 점성 평가 82
3.2.2. 초음파 분산시간에 따른 점성 평가 83
3.2.3. 희석제 사용에 따른 점성 평가 86
3.2.4. GNPs 함량에 따른 점성 평가 90
3.3. 탄소나노강화 복합재 패널(Panel) 제조 92
3.3.1. RTM(Resin Transfer Method) 성형 조건 92
3.3.2. RTM(Resin Transfer Method) 성형 96
Ⅳ. 기초 물성 시험 100
4.1. 소재 형태(Morphology) 특성 분석 100
4.2. 체적저항(Volume Resistance) 특성 분석 104
4.3. 열전도율(Thermal Conductivity) 특성 분석 108
4.3.1. 수평열전도도 특성 분석 108
4.3.2. 수직열전도도 특성 분석 112
Ⅴ. 전자파 차폐 시험 120
5.1. 전자파 차폐시험 120
5.2. 전자파 차폐시험 결과 124
Ⅵ. 기계적 물성 시험 146
6.1. 굽힘강도 특성 분석 146
6.2. 전단강도 특성 분석 158
6.3. 아이조드 충격강도 특성 분석 169
Ⅶ. 결론 174
References 177
Abstract 189
Table 1.1. Market Size and Prospects of Carbon/Polymer Composites for EMI Shielding of Automotive 22
Table 2.1. Type of Electromagnetic Wave 31
Table 2.2. Classification of Composite Materials 53
Table 3.1. Technical Data of NCF Fiber 76
Table 3.2. Viscosity Measurement Table using Zhan Cup 81
Table 3.3. Viscosity Data according to Presence of Ultrasonic Dispersion and GNPs Content 90
Table 4.1. Volume Resistance Data according to GNP Content 107
Table 4.2. Horizontal Thermal Conductivity Data according to the Content of GNPs 110
Table 4.3. LFA Measurement Results of Baseline Sample 116
Table 4.4. LFA Measurement Results of GNP 3wt% Sample 116
Table 5.1. Configuration of Electromagnetic Test Equipment 122
Table 5.2. Results of Electromagnetic Shielding Effect by GNP Content (1t) 144
Table 5.3. Results of Electromagnetic Shielding Effect by GNP Content (1.2t) 144
Table 5.4. Results of Electromagnetic Shielding Effect by GNP Content (2t) 145
Table 6.1. Table of Change in Mechanical Flexural Strength According to GNP Content (0~1.5wt%) 156
Table 6.2. Table of Change in Mechanical Flexural Strength According to GNP Content (2.0~4.0wt%) 157
Table 6.3. Table of Change in Mechanical Shear Strength According to GNP Content (0~1.5wt%) 167
Table 6.4. Table of change in mechanical shear strength according to GNPs content (2.0~4.0wt%) 168
Table 6.5. Impact Test Data 173
Fig. 1.1. Change Process from Internal Combustion Engine to Electric Vehicle 18
Fig. 1.2. Trends in the Increase in Vehicle Power Consumption 19
Fig. 1.3. Ratio of Electric Parts to Automobile Cost 20
Fig. 1.4. Global Transposition Sales Forecast for the Next 20 Years and Global Electric Vehicle Sales Trends 20
Fig. 1.5. Global New Car Sales Forecast by Vehicle Type 21
Fig. 1.6. Electromagnetic Noise in the Radio Wave Region of Electric Vehicles 24
Fig. 1.7. Electromagnetic Noise from Inverters for Special Purpose Vehicles 25
Fig. 1.8. Enhancement of Electromagnetic Shielding Effect of Materials using GNPs 29
Fig. 1.9. Prevention of Crack Transition and Improvement of Mechanical Strength of Materials using GNPs 29
Fig. 2.1. Electromagnetic Waves 30
Fig. 2.2. Noise of the Electronic Device 32
Fig. 2.3. Principle of Magnetic Filed Shielding 33
Fig. 2.4. Principle of Electric Field Shielding 33
Fig. 2.5. A Typical Arrangement for Measuring the Shielding Effectiveness 35
Fig. 2.6. Schematic of Reflection, Absorbtion and Multi-Reflection of Electromagnetic Waves 36
Fig. 2.7. Reflection Effects in the Areas of Electric 38
Fig. 2.8. Magnetic Reflections in the Area 39
Fig. 2.9. Shielding in the Incident Electromagnetic Wave 41
Fig. 2.10. Shielding Effectiveness Measurement (ASTM D 4935) 49
Fig. 2.11. Schematic Diagram of ASTM D 4935 49
Fig. 2.12. Schematic Diagram of Flanged Circular Coaxial Line Holder 50
Fig. 2.13. Schematic Diagram of Test Specimen 50
Fig. 2.14. NCF(Non-Crimped Fabric) Carbon Fiber 62
Fig. 2.15. Structure of NCF Carbon Composites 63
Fig. 2.16. Structure of Wind Blade 65
Fig. 2.17. Rear Pressure Bulkhead for the Airbus A380 66
Fig. 2.18. BMW i3 and Visby Class Corvette 67
Fig. 2.19. Structure of Graphene & CNT 68
Fig. 2.20. Graphene Nanoplatelets(GnPs) Structure 69
Fig. 2.21. Representative Molding Method of Non-Resin Injection Type 70
Fig. 2.22. Schematic View of RIM Method 72
Fig. 2.23. Schematic View of VaRTM Method 73
Fig. 2.24. Schematic View of RTM Method 74
Fig. 2.25. RTM Mold applied in this Study 75
Fig. 3.1. Non-Crimped Fabric 77
Fig. 3.2. Graphene Nanoplatelets 78
Fig. 3.3. Epoxy/Hardener 78
Fig. 3.4. Zhan Cup (ASTM D 4212) 80
Fig. 3.5. Viscosity Measurement 80
Fig. 3.6. Viscosity Data over Temperature 82
Fig. 3.7. Ultrasonic Dispersion of GNPs Samples 84
Fig. 3.8. Preliminary Research on Ultrasonic Dispersion 84
Fig. 3.9. Ultrasonic Dispersion Samples used in the Study 85
Fig. 3.10. Viscosity Data according to Ultrasonic Dispersion Time 86
Fig. 3.11. Methyl Ethyl Ketone 88
Fig. 3.12. Butyl Glycidyl Ether 88
Fig. 3.13. Viscosity Data according to Diluent Type and Amount 89
Fig. 3.14. Surface Condition due to Excessive use of Diluent 89
Fig. 3.15. Results of Viscosity according to Presence of Ultrasonic Dispersion and GNPs Content 91
Fig. 3.16. 3D Modeling of RTM Molds 92
Fig. 3.17. RTM Mold and Mounting Pictures 93
Fig. 3.18. Molding Cycle of RTM Method 94
Fig. 3.19. Pressure Condition of RTM Molding 95
Fig. 3.20. Layering Method of NCF Fiber 95
Fig. 3.21. Defoaming Process 96
Fig. 3.22. Resin after Defoaming Process 97
Fig. 3.23. Void Generation on the Surface according to the Presence or Absence of the Defoaming Process 97
Fig. 3.24. Induction of Resin Injection through an Artificial Hole 98
Fig. 3.25. Differences in Test Specimen Results according to Resin Induction 98
Fig. 3.26. Manufacturing Process 99
Fig. 3.27. Complete Manufacturing Process and Samples 99
Fig. 4.1. Optical Microscope 100
Fig. 4.2. Cross Section of NCF 100
Fig. 4.3. Cross-Section Images of NCF Fibers 101
Fig. 4.4. Scanning Electron Microscope 102
Fig. 4.5. SEM Images of GNPs Particles Following Ultrasonic Dispersion 103
Fig. 4.6. 4-Probe Measurement Method 104
Fig. 4.7. Volume Resistivity Meter 105
Fig. 4.8. Sanded Sample Surface 105
Fig. 4.9. Volume Resistance Result according to GNP Content 106
Fig. 4.10. Hot Disk Method Schematic 108
Fig. 4.11. Hot Disk Instruments and Probes (Sensors) 109
Fig. 4.12. Thermal Conductivity Measurement Sample 109
Fig. 4.13. Results of Horizontal Thermal Conductivity according to the Content of GNP 111
Fig. 4.14. Schematic Diagram of LFA Equipment 113
Fig. 4.15. Laser Flash Analysis 113
Fig. 4.16. LFA Measurement Samples 115
Fig. 4.17. LFA Measurement Results of Baseline Sample and GNPs 3wt% Sample 115
Fig. 4.18. Specific Heat Measurement Result using DSC (Base Line #1) 117
Fig. 4.19. Specific Heat Measurement Result using DSC (Base Line #2) 117
Fig. 4.20. Specific Heat Measurement Result using DSC (Base Line #3) 118
Fig. 4.21. Specific Heat Measurement Result using DSC (GNP #1) 118
Fig. 4.22. Specific Heat Measurement Result using DSC (GNP #2) 119
Fig. 4.23. Specific Heat Measurement Result using DSC (GNP #3) 119
Fig. 5.1. Drawings of ASTM D 4935 120
Fig. 5.2. Test Specimen Product on ASTM D 4935 121
Fig. 5.3. EMC Test (ASTM D 4935) 122
Fig. 5.4. Calibration Process of EMC Test Equipment 123
Fig. 5.5. Reflection Loss by GNP Content (1t) 126
Fig. 5.6. Average Reflection Loss Across All Frequencies (1t) 126
Fig. 5.7. Reflection Loss by GNP Content (1.2t) 127
Fig. 5.8. Average Reflection Loss Across All Frequencies (1.2t) 127
Fig. 5.9. Reflection Loss by GNP Content (2t) 128
Fig. 5.10. Average Reflection Loss Across All Frequencies (2t) 128
Fig. 5.11. Absorption Loss by Contents of GNP (1t) 131
Fig. 5.12. Average Absorption Loss Across All Frequencies (1t) 131
Fig. 5.13. Absorption Loss by Contents of GNP (1.2t) 132
Fig. 5.14. Average Absorption Loss Across All Frequencies (1.2t) 132
Fig. 5.15. Absorption Loss by Contents of GNP (2t) 133
Fig. 5.16. Average Absorption Loss Across All Frequencies (2t) 133
Fig. 5.17. Shielding Effectiveness by Contents of GNP (1t) 135
Fig. 5.18. Electromagnetic Wave Shielding Effect in All Frequency Bands (1t) 135
Fig. 5.19. Shielding Effectiveness by Contents of GNP (1.2t) 136
Fig. 5.20. Electromagnetic Wave Shielding Effect in All Frequency Bands (1.2t) 136
Fig. 5.21. Shielding Effectiveness by Contents of GNP (2t) 137
Fig. 5.22. Electromagnetic Wave Shielding Effect in All Frequency Bands (2t) 137
Fig. 5.23. Electromagnetic Shielding Effect around 1.28GHz (1t) 138
Fig. 5.24. Electromagnetic Shielding Effect around 1.28GHz (1.2t) 138
Fig. 5.25. Electromagnetic Shielding Effect around 1.28GHz (2t) 139
Fig. 5.26. Comparison of Reflection Loss Effect According to Frequency Band with Metal 141
Fig. 5.27. Average Reflection Loss Value of All Frequency Bands With Metal 141
Fig. 5.28. Comparison of Absorption Loss Effect According to Frequency Band With Metal 142
Fig. 5.29. Average Absorption Loss Value of All Frequency Bands with Metal 142
Fig. 5.30. Comparison of Shielding Effectiveness According to Frequency Band With Metal 143
Fig. 5.31. Average Shielding Effectiveness Value of All Frequency Bands With Metal 143
Fig. 6.1. Sketch of Bending Specimen 148
Fig. 6.2. Bending Test Specimen 148
Fig. 6.3. Bending Test in Progress 148
Fig. 6.4. Bending Test Equipment 149
Fig. 6.5. Graph of Flexural Strength Test Results (0wt%) 150
Fig. 6.6. Graph of Flexural Strength Test Results (0.5wt%) 151
Fig. 6.7. Graph of Flexural Strength Test Results (1.0wt%) 151
Fig. 6.8. Graph of Flexural Strength Test Results (1.5wt%) 152
Fig. 6.9. Graph of Flexural Strength Test results (2.0wt%) 152
Fig. 6.10. Graph of Flexural Strength Test results (2.5wt%) 153
Fig. 6.11. Graph of Flexural Strength Test Results (3.0wt%) 153
Fig. 6.12. Graph of Flexural Strength Test Results (3.5wt%) 154
Fig. 6.13. Graph of Flexural Strength Test Results (4.0wt%) 154
Fig. 6.14. Changes in Mechanical Flexural Strength According to GNP Contents 155
Fig. 6.15. Sketch of Shear Specimen 159
Fig. 6.16. Shear Strength Test Specimen 159
Fig. 6.17. 2 Axis Strain Gauge 159
Fig. 6.18. Shear Strength Test in Progress 160
Fig. 6.19. Shear Strength Test Equipment 160
Fig. 6.20. Graph of Shear Strength Test Results (0wt%) 162
Fig. 6.21. Graph of Shear strength test results (0.5wt%) 162
Fig. 6.22. Graph of Shear Strength Test Results (1.0wt%) 163
Fig. 6.23. Graph of Shear Strength Test Results (1.5wt%) 163
Fig. 6.24. Graph of Shear Strength Test Results (2.0wt%) 164
Fig. 6.25. Graph of Shear strength test Results (2.5wt%) 164
Fig. 6.26. Graph of Shear Strength Test Results (3.0wt%) 165
Fig. 6.27. Graph of Shear Strength Test Result (3.5wt%) 165
Fig. 6.28. Graph of Shear Strength Test Result (4.0wt%) 166
Fig. 6.29. Sketch of Izod Impact Test Specimen 171
Fig. 6.30. Izod Impact Test Specimen 171
Fig. 6.31. Equipment of Izod Impact Test Specimen 172
Fig. 6.32. Results of Izod Impact Test 173