In this study, Al-Si-Mg alloys are additively manufactured using a selective laser melting (SLM) process from AlSi10Mg powders prepared from a gas-atomization process. The processing parameters such as laser scan speed and laser power are investigated for 3D printing of Al-Si-Mg alloys. The laser scan speeds vary from 100 to 2000 mm/ s at the laser power of 180 and 270W, respectively, to achieve optimized densification of the Al-Si-Mg alloy. It is observed that the relative density of the Al-Si-Mg alloy reaches a peak value of 99% at 1600 mm/s for 180W and at 2000 mm/s for 270W. The surface morphologies of the both Al-Si-Mg alloy samples at these conditions show significantly reduced porosities compared to those of other samples. The increase in hardness of as-built Al-Si-Mg alloy with increasing scan speed and laser power is analyzed due to high relative density. Furthermore, it was found that cooling conditions after the heat-treatment for homogenization results in the change of dispersion status of Si phases in the Al-Si matrix but also affects tensile behaviors of Al-Si-Mg alloys. These results indicate that combination between SLM processing parameters and post-heat treatment should be considered a key factor to achieve optimized Al-Si alloy performance.

Abstract
 1. 서 론
 2. 실험방법
 3. 결과 및 고찰
 4. 결 론
 References

• 이기승(한국기계연구원 부설 재료연구소 3D프린팅소재연구센터/울산대학교 첨단소재공학부) | Gi Seung Lee (3D Printing Materials Center, Korea Institute of Materials Science/Department of Materials Science and Engineering, University of Ulsan)
• 엄영성(한국기계연구원 부설 재료연구소 3D프린팅소재연구센터) | Yeong Seong Eom (3D Printing Materials Center, Korea Institute of Materials Science)
• 김경태(한국기계연구원 부설 재료연구소 3D프린팅소재연구센터) | Kyung Tae Kim (3D Printing Materials Center, Korea Institute of Materials Science) Corresponding Author
• 김병기(울산대학교 첨단소재공학부) | Byoung Kee Kim (Department of Materials Science and Engineering, University of Ulsan)
• 유지훈(한국기계연구원 부설 재료연구소 3D프린팅소재연구센터) | Ji Hun Yu (3D Printing Materials Center, Korea Institute of Materials Science)