doi: 10.3850/S201042862015001313

Fatigue Crack Growth Ratestudy of 5E62 Alluminum Alloy Containing Erbium

Liucuiyun^1,a, Liu Bo^2,d, Xing Yu Feng^2,e, Ma Chaoli^1,b and Li Huanxi^{1,c 1}Key Laboratory of Aerospace Advanced Materials and Performance of Ministry of Education,
School of Materials Science and Engineering, Beihang University,
No.37 Xueyuan Road, Haidian district, Beijing, 100191, China ^amary11112006@126.com ^bmachaoli@buaa.edu.cn ^clhx201@buaa.edu.cn ²The Solid Mechanics Research Center, School of Aeronautic Science and Engineering,
Beihang University, No.37 Xueyuan Road, Haidian district, Beijing, 100191, China ^dliubo68@buaa.edu.cn ^exingyf@buaa.edu.cn

ABSTRACT

Cheap rare earth element erbium micro alloying played a similar role with expensive element scandium in aluminum alloys. In this paper, a new aluminum alloy 5E62 was studied which was derived from 5A06 aluminum alloy with minor addition of Er and Zr. In order to meet with the requirements of aerospace structural materials, this alloy was expected to have good overall properties of strength and fatigue crack growth resistance.The fatigue crack growth rate of two conditions sheets, cold-rolled H116 and annealed O,were studied under different stress ratios or orientations along with the tensile test results. The fatigue testing on M (T) specimens with compliance method were done.The validity and accuracy of data processing had an important role in analyzing the results objectively. The raw dadN-ΔK data was calculated from a-N data by using finite difference method and they had great dispersion. In order to solve this problem, multi-points secant method and integration method were used to fit the dadn-ΔK. The results showed that the strength of cold-rolled H116 and annealed O aluminum alloys were higher than other 5××× aluminum alloys. And the fatigue crack growth resistance of annealed O aluminum alloys was better than that of cold-rolled H116aluminum alloys.

Keywords: 5E62 aluminum alloy, Fatigue crack growth rate, Stress ratios.

---

Back to TOC