In this study, the effects of Sm addition (0, 0.05, 0.2, 0.5 wt%) on the microstructure, hardness, and electrical and thermal conductivity of Al-11Si-1.5Cu aluminum alloy were investigated. As a result of Sm addition, increment in the amount of α-Al and refinement of primary Si from 70 to 10 μm were observed due to eutectic temperature depression. On the other hand, Sm was less effective at refining eutectic Si because of insufficient addition. The phase analysis results indicated that Sm-rich intermetallic phases such as Al-Fe-Mg-Si and Al-Si-Cu formed and led to decrements in the amount of primary Si and eutectic Si. These microstructure changes affected not only the hardness but also the electrical and thermal conductivity. When 0.5 wt% Sm was added to the alloy, hardness increased from 84.4 to 91.3 Hv, and electric conductivity increased from 15.14 to 16.97 MS/m. Thermal conductivity greatly increased from 133 to 157 W/m·K.

Abstract
1. 서 론
2. 실험방법
3. 실험 결과
    3.1 Sm 첨가에 따른 미세조직 변화
    3.2 Sm 첨가에 따른 특성 변화
4. 고 찰
4. 결 론
References

• 최진주(고등기술연구원) | Jin-Ju Choi (Materials Science and Chemical Engineering Center, Institute for Advanced Engineering(IAE))
• 강유빈(고등기술연구원) | Yubin Kang (Materials Science and Chemical Engineering Center, Institute for Advanced Engineering(IAE))
• 임병용(고등기술연구원) | Byoungyong Im (Materials Science and Chemical Engineering Center, Institute for Advanced Engineering(IAE))
• 이찬기(고등기술연구원) | Chan-Gi Lee (Materials Science and Chemical Engineering Center, Institute for Advanced Engineering(IAE))
• 김한구(㈜네덱) | Hangoo Kim (NEDEC)
• 박광훈(인하대학교) | Kwang Hoon Park (Program in Metals and Materials Process Engineering, Inha University)
• 김대근(고등기술연구원) | Dae-Guen Kim (Materials Science and Chemical Engineering Center, Institute for Advanced Engineering(IAE)) Corresponding author