표제지
목차
요약 5
Chapter 1. 마찰교반공정(FSP)를 이용한 AZ31 Mg 합금의 표면 개질 10
1.1. 서론 10
1.2. 이론적 배경 12
1.2.1. 마그네슘 합금의 종류 12
1.2.2. 마그네슘 합금의 특성 12
1.2.3. Mg-Al-Zn계 합금 13
1.2.4. 마찰 교반 공정(FSP)의 원리 14
1.2.5. 마찰 교반 공정의 가공 변수 15
1.3. 국내외 연구 동향 16
1.4. 실험 방법 19
1.4.1. 시편 제작 19
1.4.2. 미세조직 분석 20
1.4.3. XRD 분석 20
1.4.4. 경도 분석 20
1.4.5. 전기화학적 분석 21
1.5. 결과 및 고찰 22
1.5.1. 회전/이동속도에 따른 FSP 시편 제작 22
1.5.2. Stir zone 위치별 미세조직 및 경도 분석 25
1.5.3. 회전/이동속도에 따른 FSPed AZ31 합금의 미세조직 및 경도 분석 28
1.5.4. FSP 공정 pass 수에 따른 AZ31 합금의 미세조직 및 경도 분석 32
1.5.5. FSP 공정 pass 수에 따른 cast AZ31 합금의 미세조직, 내식성 및 경도 분석 39
1.6. 결론 49
1.7. Reference 50
Chapter 2. FSP를 이용한 vol%에 따른 다양한 강화상/AZ31 복합재료 제작 55
2.1. 서론 55
2.2. 실험 방법 57
2.2.1. 시편 제작 57
2.2.2. 미세조직 분석 59
2.2.3. XRD 분석 59
2.2.4. 경도 분석 60
2.3. 결과 및 고찰 61
2.3.1. 강화상의 vol% 양에 따른 복합재료의 미세조직 분석 61
2.3.2. 강화상의 vol% 양에 따른 복합재료의 XRD 분석 67
2.3.3. 강화상의 vol% 양에 따른 복합재료의 경도 분석 70
2.4. 결론 74
2.5. Reference 75
Abstract 77
Table 1-1. Foreign study trend. 18
Table 1-2. Chemical composition of AZ31B-O Mg alloy. 19
Table 1-3. FSP parameter. 20
Table 2-1. Characteristics of particles. 58
Table 2-2. Chemical composition of AZ31 Mg alloy. 58
Fig. 1-1. Schematic diagram of FSP. 14
Fig. 1-2. Flowchart of FSP optimization process. 19
Fig. 1-3. Stir zone defect comparison by the transverse and rotational speed. 23
Fig. 1-4. Effect of transverse and rotational speed on macrostructure of the stir zone in the FSPed AZ31, 715 rpm (a) 157 ㎜/min, (b) 210 ㎜/min, 1000... 24
Fig. 1-5. Position optimization by comparison of grain size and microhardness on stir zone. 25
Fig. 1-6. Microstructure comparison of the FSPed AZ31 by stir zone position, Advancing side (a) 1 ㎜, (d) 2 ㎜, (g) 3 ㎜, Center (b) 1 ㎜, (e) 2 ㎜,... 26
Fig. 1-7. Grain size of the FSPed AZ31 by stir zone position. 27
Fig. 1-8. Microhardness of the FSPed AZ31 by stir zone position. 27
Fig. 1-9. Effect of transverse and rotational speed on microstructure of (a) as-received AZ3l and the stir zone in the FSPed AZ31, 715 rpm (b) 157... 30
Fig. 1-10. Grain size of the FSPed AZ31 by transverse and rotational speed. 30
Fig. 1-11. Microhardness of the FSPed AZ31 by transverse and rotational speed. 31
Fig. 1-12. Effect of number of FSP pass on microstructure of (a) as-received AZ31 and the stir zone in the FSPed AZ31, (b) 1 pass, (c) 2 pass, (d) 4 pass. 34
Fig. 1-13. Grain size of the FSPed AZ31 by number of FSP pass. 34
Fig. 1-14. SEM/EDS images of the (a) as-received AZ31, (b) lpass, (c) 2pass and (d) 4pass of FSPed AZ31. 36
Fig. 1-15. X-ray diffraction patterns, (a) all samples and (b) as-received AZ31, (c) 1 pass, (d) 2 pass, (e) 4 pass of FSPed AZ31. 37
Fig. 1-16. Microhardness profile of the FSPed AZ31 by number of FSP pass. 38
Fig. 1-17. Microhardness of the FSPed AZ31 by number of FSP pass. 38
Fig. 1-18. Effect of number of FSP pass on microstructure of the stir zone in the FSPed cast AZ31, (a) as-received cast AZ31, (b) lpass, (c) 2pass,... 41
Fig. 1-19. Grain size of the FSPed AZ31 by number of FSP pass. 41
Fig. 1-20. SEM/EDS images of the (a) as-received cast AZ31, (b) lpass, (c) 2pass and (d) 4pass of FSPed cast AZ31. 43
Fig. 1-21. Phase diagram of Mg-Al. 44
Fig. 1-22. X-ray diffraction patterns, (a) all samples and (b) as-received cast AZ31, (c) 1 pass, (d) 2 pass, (e) 4 pass of FSPed AZ31. 45
Fig. 1-23. Potentiodynamic polarization curves of the as-received and FSPed cast AZ31 samples. 46
Fig. 1-24. Corrosion potentials of the samples. 46
Fig. 1-25. Current densities of the samples. 47
Fig. 1-26. Microhardness profile of the FSPed Cast AZ31 by number of FSP pass. 48
Fig. 1-27. Microhardness of the FSPed Cast AZ31 by number of FSP pass. 48
Fig. 2-1. SEM image of (a) MWCNT, (b) Al₂O₃, (c) ZrO₂, (d) Diamond. 58
Fig. 2-2. Volume fraction parameter of various particles/AZ31 composites. 59
Fig. 2-3. Effect of volume fraction on macrostructure of the stir zone in the MWCNT/AZ31 composites, (a) 2.4 vol%, (b) 4 vol%, (c) 6.4 vol%, (d) 8 vol%. 62
Fig. 2-4. Effect of volume fraction on macrostructure of the stir zone in the Diamond/AZ31 composites, (a) 0.8 vol%, (b) 2.4 vol%, (c) 4 vol%, (d) 8 vol%. 62
Fig. 2-5. Effect of volume fraction on macrostructure of the stir zone in the Al₂O₃/AZ31 composites, (a) 2.4 vol%, (b) 4 vol%, (c) 6.4 vol%, (d) 8 vol%. 63
Fig. 2-6. Effect of volume fraction on macrostructure of the stir zone in the ZrO₂/AZ31 composites, (a) 4 vol%, (b) 6.4 vol%, (c) 8 vol%. 63
Fig. 2-7. Microstructure of as-received AZ31 Mg alloy. 63
Fig. 2-8. Effect of volume fraction on microstructure of the stir zone in the MWCNT/AZ31 composites, (a) 2.4 vol%, (b) 4 vol%, (c) 6.4 vol%, (d) 8 vol%. 64
Fig. 2-9. Effect of volume fraction on microstructure of the stir zone in the Diamond/AZ31 composites, (a) 0.8 vol%, (b) 2.4 vol%, (c) 4 vol%, (d) 8 vol%. 64
Fig. 2-10. Effect of volume fraction on microstructure of the stir zone in the Al₂O₃/AZ31 composites, (a) 2.4 vol%, (b) 4 vol%, (c) 6.4 vol%, (d) 8 vol%. 65
Fig. 2-11. Effect of volume fraction on microstructure of the stir zone in the ZrO₂/AZ31 composites, (a) 4 vol%, (b) 6.4 vol%, (c) 8 vol%. 65
Fig. 2-12. Effect of volume fraction on grain size of the stir zone in the various particles/AZ31 composites. 66
Fig. 2-13. X-ray diffraction patterns of different volume fraction in (a) MWCNT/AZ31, (b) Diamond/AZ31, (c) Al₂O₃/AZ31 and (d) ZrO₂/AZ31. 69
Fig. 2-14. Microhardness profile of different volume fraction in (a) MWCNT/AZ31, (b) Diamond/AZ31, (c) Al₂O₃/AZ31, (d) ZrO₂/AZ31. 72
Fig. 2-15. Microhardness of cross section in various particles/AZ31 composites along volume fraction. 73