Recently, considerable attention has been given to nickel-based superalloys used in additive manufacturing. However, additive manufacturing is limited by a slow build rate in obtaining optimal densities. In this study, optimal volumetric energy density (VED) was calculated using optimal process parameters of IN718 provided by additive manufacturing of laser powder-bed fusion. The laser power and scan speed were controlled using the same ratio to maintain the optimal VED and achieve a fast build rate. Cube samples were manufactured using seven process parameters, including an optimal process parameter. Analysis was conducted based on changes in density and melt-pool morphology. At a low laser power and scan speed, the energy applied to the powder bed was proportional to and not . At a high laser power and scan speed, a curved track was formed due to Plateau-Rayleigh instability. However, a wide melt-pool shape and continuous track were formed, which did not significantly affect the density. We were able to verify the validity of the VED formula and succeeded in achieving a 75% higher build rate than that of the optimal parameter, with a slight decrease in density and hardness.

Abstract
1. 서 론
2. 실험 방법
3. 결과 및 고찰
4. 결 론
감사의 글
References

• 김상욱(University of Central Florida, Department of Materials Science and Engineering,인하대학교 항공우주공학과) | Sang Uk Kim (University of Central Florida, Department of Materials Science and Engineering,Department of Aerospace Engineering, Inha University)
• 김규식(국방과학연구소, 인하대학교 신소재공학과) | Kyu-Sik Kim (Agency for Defense Development,Department of Materials Science and Engineering, Inha University)
• 손용호(University of Central Florida, Department of Materials Science and Engineering) | Yongho Sohn (Department of Materials Science and Engineering, University of Central Florida, Orlando 32816, USA)
• 이기안(인하대학교 신소재공학과) | Kee-Ahn Lee (Department of Materials Science and Engineering, Inha University, Incheon 22212, Republic of Korea) Corresponding author