Journal of Korea Foundry Society (한국주조공학회지)

Korea Foundry Society (한국주조공학회)
권호 표지

Microstructural Change in Rheocast AZ91D Magnesium Alloys with Stirring Rate and Isothermal Stirring Temperature

교반속도 및 등온교반온도에 따른 AZ91D 마그네슘합금 반응고 주조재의 미세조직 변화

  • 임창동 (한국기계연구원 재료기술연구부) ;
  • 신광선 (항공재료연구센터)
  • Published : 2003.06.20
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Abstract

Rheocasting of AZ91D magnesium alloys yielded the microstructure consisted of the spherical primary particles in the matrix which is different from conventional casting. Rheocast ingots were produced under various processing conditions using batch type rheocaster. Morphology of primary particles was changed from rosette-shape to spherical shape with increasing stirring rate$(V_s)$ and decreasing isothermal stirring temperature$(T_s)$. With increasing $V_s$, more effective shearing between the particles occurred rather than the agglomeration and clustering, so the primary particle size decreased. But with decreasing $T_s$, primary particle size increased mainly due to sintering and partially Ostwald ripening. The sphericity of primary particles increased with increasing $V_s$ and decreasing $T_s$ due to enhanced abrasion among the primary particles. The uniformity of primary particle size increased with increasing Vs and $T_s$.

Keywords

References

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