This study investigated the growth behavior and characteristics of compounds formed at the interface between a liquid Al-Si-Cu alloy and solid cast iron. Through microstructural analyses, it was observed that various AlFe and AlFeSi phases are formed at the interface, and the relative proportion of each phase changes when small amounts of strontium are added to the Al alloy. The results of the microstructural analysis indicate that the primary phases of the interfacial compounds in the Al-Si-Cu base alloy are Al8Fe2Si and Al4.5FeSi. However, in the Sr-added alloys, significant amounts of binary AlFe intermetallic compounds such as Al5Fe2 and Al13Fe4 formed, in addition to the AlFeSi phases. The inclusion of Sr has a slight diminishing effect on the rate at which the interfacial compounds layer thickens during the time the liquid Al alloy is in contact with the cast iron. The study also discusses the nano-indentation hardness and micro-hardness of the interfacial phases.

1. Introduction
2. Experimental Procedures
3. Results and Discussion
    3.1. Interfacial compound at the Al-Si-Cu/cast ironjunction
    3.2. Effects of Sr additions
    3.3. EBSD analyses of the interfacial compounds
    3.4. Hardness of the interfacial compounds
4. Conclusion
Acknowledgement

• Kyoung-Min Min(Department of Materials Science and Engineering, Hanbat National University, Daejeon 34158, Republic of Korea)
• Je-Sik Shin(Research Institute of Advanced Manufacturing Technology, Korea Institute of Industrial Technology, Incheon 21999, Republic of Korea)
• Jeong-Min Kim(Department of Materials Science and Engineering, Hanbat National University, Daejeon 34158, Republic of Korea) Corresponding author