Journal of the Korean Society of Propulsion Engineers (한국추진공학회지)

The Korean Society of Propulsion Engineers (한국추진공학회)
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Fatigue Crack Growth Behavior of Powder Metallurgical Nickel-based Superalloy using DCPD Method at Elevated Temperature

DCPD법을 이용한 분말야금 니켈기 초내열합금의 고온 피로균열진전거동

  • Na, Seonghyeon (School of Mechanical Engineering, Chungnam National University) ;
  • Oh, Kwangkeun (School of Mechanical Engineering, Chungnam National University) ;
  • Kim, Hongkyu (The 4th R&D Institute - 4th Directorate, Agency for Defense Development) ;
  • Kim, Donghoon (The 4th R&D Institute - 4th Directorate, Agency for Defense Development) ;
  • Kim, Jaehoon (School of Mechanical Engineering, Chungnam National University)
  • Received : 2015.12.01
  • Accepted : 2016.03.14
  • Published : 2016.04.01
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Abstract

Powder metallurgy nickel based superalloy has been used in a high temperature part of turbine engine for airplane. The fatigue crack growth behavior was investigated using CT specimens for the materials at room temperature(R.T.), $600^{\circ}C$ and $700^{\circ}C$. The direct current potential drop(DCPD) method suggested by ASTM E647 was used to measure the crack length during fatigue crack growth at various stress ratios. The fatigue crack growth rate at R=0.5 was faster than that at R=0.1 for all temperature conditions and increased with the increase of stress ratio and temperature. Fractography was conducted for analysis of fracture mechanism.

분말야금 니켈기 초내열합금은 항공기 터빈 엔진의 고온용 부품으로 사용되고 있다. 본 연구에서는 상온, $600^{\circ}C$ 및 $700^{\circ}C$에서 CT시편을 이용하여 피로균열진전거동이 평가되었다. ASTM E647에서 제시한 직류전위차법이 피로균열진전 동안에 균열 길이를 측정하기 위하여 사용되었다. 응력비 0.5에서 피로균열진전속도는 응력비 0.1에서와 비교하여 더 빠르게 나타났다. 피로균열진전속도는 응력비와 온도의 증가와 함께 증가하였다. 파단면 관찰은 파괴메커니즘 분석을 위해 수행하였다.

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References

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