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pISSN : 1598-706X / eISSN : 2288-8381


한국주조공학회지 (26권3호 140-145)

The Effect of Sr on the Microstructures of Hypereutectic Al-Si Alloys

과공정 Al-Si 합금의 미세조직에 영향을 미치는 Sr 의 영향

Myunghan K im

Chungbuk National University,


Sr, added in the hypereutectic Al-Si alloys, is absorbed on the surfaces o f primary Si as well as eutectic Si, and can change the growth mode o f primary Si from non-faceted to faceted mode, as the amount o f Sr increases larger than 0.04 wt.%, even though it cannot affect the grain size o f primary Si, significantly. The EBSD analysis shows that the fraction o f Z3 boundary(twin boundary) increases as the amount o f Sr in the hypereutectic Al-Si alloys increase until the over-modification occurs at 1.6 wt.%Sr and proves that the change in growth mode o f primary Si results from the change o f TPRE growth to IIT growth.


Hypereutectic Al-Si, Growth mode, EBSD analysis, S3 boundary