고강도 Al-Zn-Mg-Cu 합금에서 조성에 따른 응력부식균열 특성
Stress Corrosion Cracking of High Strength Al-Zn-Mg-Cu Aluminum Alloy with Different Compositions
1
조회
0
다운로드
2
인용
0
참고문헌
키워드
초록
High strength 7xxx series Al-Zn-Mg alloy have been investigated for using light weight automotive parts especially for bump back beam. The composition of commercial 7xxx aluminum has the Zn/Mg ratio about 3 and Cu over 2wt%, but this composition isn't adequate for appling to automotive bump back beam due to its high resistance to extrusion and bad weldability. In this study the Zn/Mg ratio was increased for better extrusion and Cu content was reduced for better welding. With this new composition we investigated the effect of composition on the resistivity against stress corrosion cracking. As the Zn/Mg ratio is increased fracture energy obtained by slow strain rate test was decreased, which means degradation of SCC resistance. While the fracture energy was increased with Cu contents although it is below 1%, which means improvement of SCC resistance. These effects of composition change on the SCC resistivity was identified by observing the fracture surface and crack propagation.
Abstract
High strength 7xxx series Al-Zn-Mg alloy have been investigated for using light weight automotive parts especially for bump back beam. The composition of commercial 7xxx aluminum has the Zn/Mg ratio about 3 and Cu over 2wt%, but this composition isn't adequate for appling to automotive bump back beam due to its high resistance to extrusion and bad weldability. In this study the Zn/Mg ratio was increased for better extrusion and Cu content was reduced for better welding. With this new composition we investigated the effect of composition on the resistivity against stress corrosion cracking. As the Zn/Mg ratio is increased fracture energy obtained by slow strain rate test was decreased, which means degradation of SCC resistance. While the fracture energy was increased with Cu contents although it is below 1%, which means improvement of SCC resistance. These effects of composition change on the SCC resistivity was identified by observing the fracture surface and crack propagation.
참고문헌 (9)
- Y. W. Yun, "Evaluation on the mechanical Properties and Corrosion Resistance of Extruded Aluminum Alloys", 2007 자동차기술통합 workshop, pp.157~ (2007)
- F. S. Bovard, "Environmentally Induced Cracking Of An Al-Zn-Mg-Cu Alloy", pp.4~15 (2005), University of Pittsburgh
- Alcoa Report, "F. Bovard", 21~, pp.No. 471-LC-11 (1996)
- W. Gruhl, , Zeit. Metallkunde, 75, pp.819~826 (1984)
- B. Sarkar, , Metall. Trans, 12A, pp.1939~1943 (1981)
- M. Puiggali, , Corros. Sci, 40, pp.805~ (1998)
- S. S. Kim, , Scripta Metall, 22, pp.91~ (1998)
- J. C. Lin, , Corrosion Sci. Eng, A303, pp.3139~ (2001)
- B. Davo', , Corrosion Science, 48, pp.4119~4124 (2006)