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Nano-Scale Observation of Fatigue Striations for Aluminum Alloy

알루미늄 합금 피로 스트라이에이션의 나노 스케일 관찰

  • Choe, Seong-Jong (Dept.of Mechanical Engineering, Yeungnam University) ;
  • Gwon, Jae-Do (Dept.of Mechanical Engineering, Yeungnam University) ;
  • Ishii, Hitoshi
  • 최성종 (영남대학교 기계공학부) ;
  • 권재도 (영남대학교 기계공학부) ;
  • Published : 2001.07.01

Abstract

Atomic Force Microscope (AFM) was used to study cross sectional profiles and dimensions of fatigue striations in 2017-T351 aluminum alloy. Their widths(SW) and heights (SH, SH(sub)h, SH(sub)ι) were measured from the cross sectional profiles of three-dimension AFM images. The following results that will be helpful to understand the fatigue crack growth mechanism were obtained. (1) The relation of SH=$\alpha$(SW)(sup)1.2 was obtained. (2) The ratio of the striation height to its width SH/SW, SH(sub)h/SW and SH(sub)ι/SW did not depend on the stress intensity factor range ΔK and the stress ratio R( =P(sub)min/P(sub)max = K(sub)min/K(sub)max). (3) Effect of precipitate on the morphology of striation was changed by the relative dimensional difference between the striation width SW and the precipitates. From these results, the applicability of the AFM to nano-fractography is discussed.

Keywords

AFM;Service Loading;Stress Intensity Factor Range;Fatigue Crack Growth;Striation Width;Striation Height;Stress Ratio;Nano-Fractography

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