This study investigates the effect of process stopping and restarting on the microstructure and local nanoindentation properties of 316L stainless steel manufactured via selective laser melting (SLM). We find that stopping the SLM process midway, exposing the substrate to air having an oxygen concentration of 22% or more for 12 h, and subsequently restarting the process, makes little difference to the density of the restarted area (~ 99.8%) as compared to the previously melted area of the substrate below. While the microstructure and pore distribution near the stop/restart area changes, this modified process does not induce the development of unusual features, such as an inhomogeneous microstructure or irregular pore distribution in the substrate. An analysis of the stiffness and hardness values of the nano-indented steel also reveals very little change at the joint of the stop/restart area. Further, we discuss the possible and effective follow-up actions of stopping and subsequently restarting the SLM process.

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

• 주현진(인하대학교 산학협력단 재료연구실) | Hyunjin Joo (Material Research Institute, Inha University, 22212, Republic of Korea)
• 우정민(University of Central Florida, Department of Materials Science and Engineering) | Jeongmin Woo (Department of Materials Science and Engineering, University of Central Florida, Orlando, 32816, USA)
• 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