사형주조한 Mg-Nd-Zr-Zn합금의 고온 크리이프강도

High Temperature Creep Strength of Mg-Nd-Zr-Zn Alloy in Sand Castings

  • 강대민 (부경대학교 기계공학과) ;
  • 박경도 (부경대학교 대학원 생산자동화공학과) ;
  • 박지희 (부경대학교 대학원 생산자동화공학과)
  • 투고 : 2011.08.05
  • 심사 : 2011.12.06
  • 발행 : 2011.12.31

초록

Magnesium alloys have been focussed for the applications for lightweight of vehicle and electronics due to their high strength, low specific density and good damping capacity. This paper deals with the creep strength of Mg-Nd-Zr-Zn alloy. For the alloy, pure magnesium(99.9%) was melt with atmosphere of $0.3%SF_6$ and $25%CO_2$. After melting, 0.3% of zinc was inserted to stir for 10min at elevated temperature of $770^{\circ}C$. Master alloys of Mg-15%Nd and Mg-15%Zr were stirred in furnace. The creep tests were performed to obtain creep rate and rupture in the temperature range of 200 to $220^{\circ}C$ and 280 to $310^{\circ}C$ at an applied stress of 156 to 172MPa and 78 to 94MPa, respectively. The deformation mechanism was predicted dislocation climb from measured apparent activation energy and stress exponent. Also the increaser the temperature and stress the lower the stress exponent and activation energy. Finally, LMP parameter gives good information for the predicted creep rupture life.

키워드

참고문헌

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