Effect of Sb on the Creep Behavior of AZ31 Alloy

AZ31합금의 크립특성에 미치는 Sb의 영향

  • 손근용 (한국기계연구원 재료연구부 경량재료그룹) ;
  • 티안수구이 (한국기계연구원 재료연구부 경량재료그룹) ;
  • 김경현 (한국기계연구원 재료연구부 경량재료그룹)
  • Published : 2003.12.30

Abstract

The effects of antimony addition on the microstructures and creep behavior of AZ31 magnesium alloy have been investigated. Constant load creep tests were carried out at temperatures ranging from $150^{\circ}C$ to $200^{\circ}C$, and an initial stress of 50MPa for AZ31 alloys containing antimony up to 0.84% by weight. Results show that small additions of antimony to AZ31 effectively decreased the creep extension and steady state creep rates. The steady state creep rate of AZ31 was reduced 2.5 times by the addition of 0.84% of antimony. The steady state creep rate of AZ31-0.84Sb alloy was controlled by dislocation climb in which the activation energy for creep was 128 kJ/mole. The microstructure of as-cast AZ31-0.84%Sb alloy showed the presence of $Mg_3Sb_2$ precipitates dispersed throughout the matrix. The main reason for the higher creep resistance in AZ31-Sb alloys is due to the presence $Mg_3Sb_2$, which effectively hindered the movement of dislocations during the elevated temperature creep.

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