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Fe-Mn-Si계 합금의 마르텐사이트 변태 특성에 미치는 결정립 크기의 영향

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Author(s)
조우석
Issued Date
2004
Abstract
Effects of thermomechanical treatment and colling rate on the microstructure and grain size has been investigated in bulk- and ribbon-type Fe-Mn-Si based shape memory alloy, and the correlationship between those intrinsic factors and martensitic transformation characteristics has been discussed.
The results obtained are summarized as follows.
(1) In F5 plate which revealed γ→ε→α' martensitic transformation behavior by cold rolling, α' martensite were reversed to austenite while deformed grains were recrystallized by annealing at 700℃×1hr. The reversed austenite grains were grown and the volume fraction of thermal ε martensite was increased.
(2) In F3 plate which revealed γ→ε martensitic transformation behavior by cold rolling, deformed grains were recrystallized by annealing above 800℃×1hr and the volume fraction of thermal ε martensite was about 10%.
(3) When Fe-Mn-Si based SMA ribbons were fabricated by RSP, grain size of the ribbon was refined up to 4 ㎛ and the uniformity of grains were improved by increasing wheel speed i.e cooling rate. The volume fraction of thermal ε martensite was increased by increasing colling rate.
(4) M (s) and A_(s) temperatures of the melt-spun ribbon were decreased while transformation temperature hysteresis(A_(f)-M_(s)) was increased by increasing wheel speed.
(5) Refined grains of the melt-spin ribbon were partially grown by annealing above 300℃×3min. By increasing annealing temperature, the volume fraction of thermal ε martensite was increased and that of α′martensite were also highly increased in the resultant ribbons.
(6) M_(s) temperature of annealed ribbon was higher than that of as-spun ribbon and transformation temperature hysteresis(A_(f)-M_(s)) was decreased by increasing annealing temperature.
Alternative Title
Effect of Grain Size on the Martemsitic Transformation Characteristics in Fe-Mn-Based Alloys
Alternative Author(s)
Cho, Woo-Suk
Affiliation
조선대학교 대학원
Department
산업대학원 금속재료공학과
Advisor
장우양
Awarded Date
2005. 2
Table Of Contents
목차
LIST OF TABLES = Ⅰ
LIST OF FIGURES = Ⅱ
ABSTRACT = Ⅴ
제 1 장 서론 = 1
제 2 장 이론적 배경 = 4
2. 1 철계 합금의 마르텐사이트 변태 = 4
2. 2 Fe-Mn-Si계 합금의 마르텐사이트변태 기구 = 5
2.2.1 Pole 기구 = 6
2.2.2 적층결함 기구 = 6
2. 3 Fe-Mn-Si계 합금의 형상기억효과 = 11
2. 4 Fe-Mn-Si계 합금의 형상기억효과에 미치는 제 인자 = 14
2.4.1 합금조성 = 14
2.4.2 응력 = 15
2.4.3 예비성형 = 16
2.4.4 결정방위 = 16
2.4.5 TN 온도 = 17
2.4.6 결정립 크기 = 18
2.4.7 가공열처리 = 18
2.4.8 석출물 및 첨가원소의 영향 = 19
제 3 장 실험방법 = 21
3. 1 합금설계 및 용해 = 21
3. 2 균질화처리 및 열간 압연 = 22
3. 3 냉간압연 = 21
3. 4 합금 리본의 제조 = 22
3. 5 열처리 = 23
3. 6 미세조직 관찰 및 결정립 측정 = 23
3. 7 X-선 회절 시험 = 23
3. 8 변태온도 측정 = 23
제 4 장 실험결과 및 고찰 = 25
4. 1 판재 합금에서의 변태특성에 미치는 결정립 크기의 영향 = 25
4.1.1 합금조성 및 어닐링에 따른 미세조직 = 25
4.1.2 결정립 크기에 따른 thermal ε 마르텐사이트 및 항복강도 변화 = 29
4.1.3 결정립 크기에 따른 형상회복율 변화 = 34
4. 2 Melt-spun 리본에서의 마르텐사이트변에 미치는 결정립 크기의 영향 = 36
4.2.1 Melt-spun 리본의 냉각속도에 따른 결정립 크기 및 상 변화 = 36
4.2.2 휠 회전속도에 따른 변태온도 변화 = 49
4.2.3 열처리 온도에 따른 미세조직 및 변태 특성 = 53
제 5 장 결론 = 61
참고 문헌 = 62
Degree
Master
Publisher
조선대학교 대학원
Citation
조우석. (2004). Fe-Mn-Si계 합금의 마르텐사이트 변태 특성에 미치는 결정립 크기의 영향
Type
Dissertation
URI
https://oak.chosun.ac.kr/handle/2020.oak/1872
Appears in Collections:
Engineering > Theses(Master)(산업기술창업대학원)
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