본문 바로가기 주메뉴 바로가기
국회도서관 홈으로 정보검색 소장정보 검색

목차보기

표제지

목차

Abstract 9

I. 서론 12

1. 연구 배경 12

2. 이론적 배경 16

2.1. 부식의 정의 16

2.2. 알루미늄의 부식 개요 16

2.3. 부식의 원인 17

2.4. 부식의 종류 17

2.4.1. 균일 부식(Uniform Attack) 17

2.4.2. 갈바닉 부식(Galvanic Corrosion) 17

2.4.3. 틈 부식(Crevice Corrosion) 20

2.4.4. 공식(Pitting Corrosion) 21

2.4.5. 입계 부식(Intergranular Corrosion) 22

2.4.6. 응력 부식 균열(Stress Corrosion Cracking) 22

2.5. 갈바닉 부식에 대한 이해 23

2.5.1. 기본 이론 23

2.5.2. 면적의 영향 24

2.5.3. 갈바닉쌍에서의 분극저항 25

2.6. 금속의 피로 거동 이해 28

2.6.1. 피로파괴의 정의 28

2.6.2. 피로파괴를 야기하는 요인 29

2.6.3. 피로파괴 메커니즘 29

II. 실험 방법 31

1. 실험 재료 및 시편 31

2. 부식 실험 38

3. 염수 분무 시험 43

4. 인장 실험 46

5. 피로 시험 50

5.1. 실험 환경 및 장비 50

5.2. 반복 하중하의 피로 실험 51

III. 실험 결과 및 고찰 53

1. 부식 실험 53

2. 인장 시험 55

3. 피로 시험 결과 및 고찰 57

IV. 결론 62

참고 문헌 63

표목차

Table 1. Boeing Airplanes in Service 14

Table 2. Classification of Dissimilar Metals for Design 20

Table 3. Combination of Alloy and Stress Corrosion Cracking Environment 23

Table 4. Chemical Composition(wt.%) of Al 6013 31

Table 5. Mechanical Properties 32

Table 6. Chemical Composition(wt.%) of Al 7075 33

Table 7. Mechanical Properties 34

Table 8. Net Tension Properties in Air Condition 48

Table 9. Net Tension Properties after 25 days Salt Spray 50

Table 10. Corrosion Potential of Test Materials 54

Table 11. Tension Properties of Specimens Atmosphere Condition and Pre_exposure (3.5 % NaCl Salt Spray after 25 days) 56

그림목차

Fig. 1. Typical Causes and Sources of Corrosion 19

Fig. 2. Corrosion Cell 20

Fig. 3. Pitting Corrosion of Al 7050-T73 Forging 22

Fig. 4. Polarization Curve of Galvanic Potential between Two Different Materials 26

Fig. 5. Polarization Curve of Several Materials at 3.5% NaCl 27

Fig. 6. S-N Curve (MIL-HDBK-5H, 7075-T6) 30

Fig. 7. Net Tension Test Specimen 34

Fig. 8. Microstructure of Al 6013-T62, L-surface 35

Fig. 9. Microstructure of Al 7075-T6, L-surface 35

Fig. 10. Microstructure of Al 2117-T4, ST-surface 36

Fig. 11. Microstructure of Al 7050-T73, ST-surface 36

Fig. 12. Microstructure of Nickel-Copper Alloy, ST-surface 37

Fig. 13. Apparatus of Corrosion Test 39

Fig. 14. Polarization Curve of Al 6013-T62 at 3.5% NaCl Solution 40

Fig. 15. Polarization Curve of Al 7075-T6 at 3.5% NaCl Solution 40

Fig. 16. Polarization Curve of Al 2117-T4 at 3.5% NaCl Solution 41

Fig. 17. Polarization Curve of Al 7050-T73 at 3.5% NaCl Solution 41

Fig. 18. Polarization Curve of Nickel-copper alloy at 3.5% NaCl Solution 42

Fig. 19. Equipment of Salt Spray Test Chamber 44

Fig. 20. Salt Spray Chamber Inside View 45

Fig. 21. One of Salt Spray Test Specimen after 15 days Exposure 45

Fig. 22. Equipment of Tension Test 46

Fig. 23. Specimens after Net Tension Test 47

Fig. 24. Stress/strain Curve of Al 6013-T62 48

Fig. 25. Stress/strain Curve of Al 7075-T6 49

Fig. 26. Fatigue Test Equipment (Instron 8872) 51

Fig. 27. Polarization Curve of Test Specimens at 3.5% NaCl Solution 53

Fig. 28. Corrosion Potential of Test Materials 54

Fig. 29. Allowable Stress of Al 6013-T62 Atmosphere Condition and Pre_exposure (3.5% NaCl Solution Salt Spray 25 days) 56

Fig. 30. Allowable Stress of Al 7075-T6 Atmosphere Condition and Pre_exposure (3.5% NaCl Solution Salt Spray 25 days) 57

Fig. 31. Fatigue Life of AL6013-T62 with Atmosphere Condition and Pre_exposure (3.5% NaCl Solution Salt Spray 38 days) 58

Fig. 32. Fatigue Life of AL7075-T6 with Atmosphere Condition and Pre_exposure (3.5% NaCl Solution Salt Spray 38 days) 59

Fig. 33. Fracture Analysis of Al 6013-T62 after 38 days Salt Spray 60

Fig. 34. Fracture Analysis of Al 7075-T6 after 38 days Salt Spray 61