서지주요정보
Al 7039 의 피로균열 진전 거동에 관한 연구 = A study on fatigue crack growth behavior of Al 7039
서명 / 저자 Al 7039 의 피로균열 진전 거동에 관한 연구 = A study on fatigue crack growth behavior of Al 7039 / 김영종.
저자명 김영종 ; Kim, Young-Jong
발행사항 [서울 : 한국과학기술원, 1983].
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소장정보

등록번호

4102198

소장위치/청구기호

학술문화관(문화관) 보존서고

MME 8308

SMS전송

도서상태

이용가능

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반납예정일

초록정보

The fatigue crack growth behavior of the high strength Al 7039 alloy was investigated in this study. Crack growth behaviors of CT specimens under five different aging conditions were investigated and crack closure phenomena in specimens with different thickness were studied. The aging conditions were peak-aging (24 h. at 120℃), over-aging (36 h. at 120℃), over-aging (48 h. at 120℃), double aging (16 h. at 77℃ and 14 h. at 160℃), and double aging (8 h. at 107℃ and 16 h. at 150℃) respectively. The microstructures of the specimens were examined by the optical and electromicroscopy to find the relationship between the microstructural features and their fatigue properties. Precipitate free zones (PFZ) were observed near the grain boundary. The threshold stress intensity range, $ΔK_{th}$, was largest for peak-aging condition where the width of the PFZ was smallest. The fatigue crack growth rate, however, for peak-aging condition appeared to be rather high. Kikukawa-Compliance method using a conventional clip on gauge was employed to investigate the effect of thickness on crack growth and crack closure. At R=0.05, the fatigue crack growth rate tended to increase with increasing thickness. However, at R=0.5 thickness did not appear to affect the fatigue crack growth rate. In addition it is found that $K_{op}/K_{max}$ suddenly decreased with increasing $K_{max}$ in region I, while constant in region II. In region II, fatigue crack growth rate independent of thickness could be well represented by $ΔK_{eff}$. On the other hand, in region I the growth rate was dependent on the thickness.

서지기타정보

서지기타정보
청구기호 {MME 8308
형태사항 iv, 42 p. : 삽도 ; 26 cm
언어 한국어
일반주기 저자명의 영문표기 : Young-Jong Kim
지도교수의 한글표기 : 엄윤용
지도교수의 영문표기 : Youn-Young Earmme
학위논문 학위논문(석사) - 한국과학기술원 : 기계공학과,
서지주기 참고문헌 : p. 24-26
주제 Metals --Fatigue.
Fracture mechanics.
Aluminum alloys.
Microstructure.
Precipitation (Meteorology)
피로 균열. --과학기술용어시소러스
균열 전파. --과학기술용어시소러스
파괴 역학. --과학기술용어시소러스
석출 (금속) --과학기술용어시소러스
미세 구조. --과학기술용어시소러스
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