Aluminum alloys, known for their high strength-to-weight ratios and impressive electrical and thermal conductivities, are extensively used in numerous engineering sectors, such as aerospace, automotive, and construction. Recently, significant efforts have been made to develop novel aluminum alloys specifically tailored for additive manufacturing. These new alloys aim to provide an optimal balance between mechanical properties and thermal/ electrical conductivities. In this study, nine combinatorial samples with various alloy compositions were fabricated using direct energy deposition (DED) additive manufacturing by adjusting the feeding speeds of Al6061 alloy and Al-12Si alloy powders. The effects of the alloying elements on the microstructure, electrical conductivity, and hardness were investigated. Generally, as the Si and Cu contents decreased, electrical conductivity increased and hardness decreased, exhibiting trade-off characteristics. However, electrical conductivity and hardness showed an optimal combination when the Si content was adjusted to below 4.5 wt%, which can sufficiently suppress the grain boundary segregation of the α- Si precipitates, and the Cu content was controlled to induce the formation of Al2Cu precipitates.

1. Introduction
2. Experimental
3. Results and Discussion
4. Conclusion
Acknowledgement

• 전서연(국민대학교 신소재공학부) | Seoyeon Jeon (School of Materials Science and Engineering, Kookmin University, Seoul 02707, Republic of Korea)
• 박수원(국민대학교 신소재공학부) | Suwon Park (School of Materials Science and Engineering, Kookmin University, Seoul 02707, Republic of Korea)
• 송용욱(국민대학교 신소재공학부) | Yongwook Song (School of Materials Science and Engineering, Kookmin University, Seoul 02707, Republic of Korea)
• 박지원(국민대학교 신소재공학부) | Jiwon Park (School of Materials Science and Engineering, Kookmin University, Seoul 02707, Republic of Korea)
• 박현영(국민대학교 신소재공학부) | Hyunyoung Park (School of Materials Science and Engineering, Kookmin University, Seoul 02707, Republic of Korea)
• 이보람(국민대학교 신소재공학부) | Boram Lee (School of Materials Science and Engineering, Kookmin University, Seoul 02707, Republic of Korea)
• 최현주(국민대학교 신소재공학부) | Hyunjoo Choi (School of Materials Science and Engineering, Kookmin University, Seoul 02707, Republic of Korea) Corresponding author