표제지
목차
국문초록 11
제1장 서론 13
제1절 연구 배경 및 필요성 13
제2절 연구 내용 17
제2장 이론적 배경 18
제1절 알루미늄 합금 18
제2절 소재 강화 원리 19
제3절 알루미늄 합금의 열처리 강화 20
제3장 연구 방법 23
제1절 공정 모사 실험 23
제2절 물성 분석 방법 24
제3절 미세 조직 분석 방법 24
제4절 성분 분석 방법 24
제5절 열특성 분석 방법 25
제4장 연구 결과 28
제1절 고온 압출 모사 실험 28
제2절 압출재의 기계적 특성 제어 메커니즘 40
제3절 고온 열화 특성 분석 73
제5장 결론 82
제1절 연구 결론 82
제2절 향후 과제 83
참고문헌 85
Table 1. Aging treatment symbol for aluminum 22
Table 2. Composition table of domestically produced AA 2026 used in the study 26
Table 3. Homogenization heat treatment and extrusion conditions 26
Table 4. Hardness change according to solution conditions 32
Fig. 1. Status of companies in the domestic aviation industry 16
Fig. 2. a) Compression specimen specifications, b) ASTM E8/E8M subsize plate specimen specifications 27
Fig. 3. Microstructural changes due to hot compression 30
Fig. 4. Confirmation of precipitate melting point through TG-DTA 31
Fig. 5. Mole fraction by temperature calculated through Thermo-Calc 31
Fig. 6. EPMA Mapping results before and after solution treatment 33
Fig. 7. XRD analysis results before and after compression and solution treatment 34
Fig. 8. How to Calculate Dislocation Density from XRD Peaks
Fig. 9. Hardness change due to aging treatment 37
Fig. 10. Changes in fine precipitates of AA 2026 aged at 160℃ 38
Fig. 11. Changes in fine precipitates of AA 2026 aged at 190℃ 39
Fig. 12. Material heat treatment and aging process and deformed specimen 42
Fig. 13. Strength change due to cold deformation 43
Fig. 14. XRD graph according to cold deformation 44
Fig. 15. dislocation density change according to cold deformation 45
Fig. 16. SS curve of naturally aged specimen after cold deformation 49
Fig. 17. Changes in physical properties according to the amount of pre-strain of naturally aged specimens after cold deformation 50
Fig. 18. Effect of strengthening physical properties according to cold deformation and processing steps 51
Fig. 19. Dislocation density before and after aging and physical property changes after aging according to the amount of cold deformation 52
Fig. 20. Types of precipitates found in naturally aged materials 53
Fig. 21. Microstructure according to the amount of deformation of naturally aged specimens after cold deformation 54
Fig. 22. SS curve of specimen artificially aged for 4 hr at 190℃ 57
Fig. 23. Changes in physical properties according to the amount of pre-strain of artificially aged specimens after cold deformation 58
Fig. 24. Effect of strengthening physical properties according to cold deformation and processing steps 59
Fig. 25. Dislocation density before and after aging and physical property changes after aging according to the amount of cold deformation 60
Fig. 26. Microstructure according to the amount of deformation of artificially aged specimens after cold deformation 61
Fig. 27. SS curve of specimen artificially aged for 8 hr at 190℃ 64
Fig. 28. Changes in physical properties according to the amount of pre-strain of artificially aged specimens after cold deformation 65
Fig. 29. Microstructure according to the amount of deformation of artificially aged specimens after cold deformation 66
Fig. 30. Dislocation density before and after aging and physical property changes after aging according to the amount of cold deformation 67
Fig. 31. Effect of strengthening physical properties according to cold deformation and processing steps 68
Fig. 32. Changes in yield strength depending on aging treatment conditions and pre-strain rate 70
Fig. 33. Changes in tensile strength depending on aging treatment conditions and pre-strain rate 71
Fig. 34. Changes in elongation according to aging treatment conditions and pre-strain rate 72
Fig. 35. Tensile test results of AA 2026-T4 exposed to 100℃ for 100 hours 75
Fig. 36. Changes in physical properties of AA 2026-T4 exposed to 100℃ for 100 hours 76
Fig. 37. Tensile test results of AA 2026-T4 exposed to 200℃ for 100 hours 77
Fig. 38. Changes in physical properties of AA 2026-T4 exposed to 200℃ for 100 hours 78
Fig. 39. Tensile test results of AA 2026-T4 exposed to 300℃ for 100 hours 79
Fig. 40. Changes in physical properties of AA 2026-T4 exposed to 300℃ for 100 hours 80
Fig. 41. Microstructural changes upon high temperature exposure 81