• Title/Summary/Keyword: 피로노치감도

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Improvement of Fatigue Properties in Ultrafine Grained Pure Ti after ECAP(Equal Channel Angular Pressing) (ECAP가공에 의한 초미세립 순수 티타늄의 피로 특성 향상)

  • Lee, Young-In;Park, Jin-Ho;Choi, Deok-Ho;Choi, Myung-Il;Kim, Ho-Kyung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.11 s.242
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    • pp.1494-1502
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    • 2005
  • Fatigue life and notch sensitivity of the ultrafine grained pure Ti produced by ECAP was investigated. The ECAPed sample with the true strain of 460$\%$ showed near equiaxed grains with an average size of about 0.3 $\mu$m. After ECAP, the ultimate tensile strength was increased by 60$\%$, while the tensile ductility was decreased by 31$\%$. The ECAPed ultrafine grained pure Ti samples showed high notch sensitivity and significant improvement of high cycle fatigue limit by a factor of 1.67. The ECAPed samples also show high notch sensitivity (K$_{f}$/K$_{t}$ = 0.96). It can be concluded that ECAP is the effective process for achieving high fatigue strength in Ti by increasing its tensile strength through grain refinement