Fatigue Crack Propagation Behavior of Fine Grained Al-5083 Alloy Produced by Severe Plastic Deformation

강소성법을 이용한 미세립 Al-5083 합금의 피로균열전파 거동

  • Published : 2007.04.30

Abstract

Fine grained Al-5083 alloy produced by equal channel angular pressing (ECAP) at $120^{\circ}C$ was tested for investigating mechanical properties and crack growth propagation behavior. Also, FEM stress and strain analysis for the samples during ECAP were investigated, using a plastic deformation analysis software DEFORM 2-D. Coarse grained as-received samples exhibited UTS of 255.6MPa with a elongation to failure of 34.4%. By contrast, the ECAPed fine grained samples exhibited UTS of 362.0MPa with a elongation to failure of 12.9%. Fatigue crack growth resistance and threshold of fine grained samples were lower than that of as-received coarse grained samples. The higher fatigue crack growth rate in the fine grained ECAPed samples may partially arise from small roughness closure effect due to smoother fracture surfaces.

Keywords

5083-Al alloy;fine-grained microstructure;FEM simulation;fatigue crack growth rate

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