Powder flowability is critical in additive manufacturing processes, especially for laser powder bed fusion. Many powder features, such as powder size distribution, particle shape, surface roughness, and chemical composition, simultaneously affect the flow properties of a powder; however, the individual effect of each factor on powder flowability has not been comprehensively evaluated. In this study, the impact of particle shape (sphericity) on the rheological properties of Ti-6Al-4V powder is quantified using an FT4 powder rheometer. Dynamic image analysis is conducted on plasma-atomized (PA) and gas-atomized (GA) powders to evaluate their particle sphericity. PA and GA powders exhibit negligible differences in compressibility and permeability tests, but GA powder shows more cohesive behavior, especially in a dynamic state, because lower particle sphericity facilitates interaction between particles during the powder flow. These results provide guidelines for the manufacturing of advanced metal powders with excellent powder flowability for laser powder bed fusion.

Abstract
1. 서 론
2. 실험 방법
    2.1. 동적특성
    2.2. 벌크특성
    2.3. 전단 특성
3. 실험결과
    3.1. 분말특성
    3.2. 유변특성
4. 고 찰
5. 결 론
References

• 김태윤(부산대학교 재료공학과) | T. Y. Kim (School of Materials Science and Engineering, Pusan National University, Busan 46241, Republic of Korea)
• 강민혁(부산대학교 재료공학과) | M. H. Kang (School of Materials Science and Engineering, Pusan National University, Busan 46241, Republic of Korea)
• 김재혁(한국재료연구원 타이타늄연구실) | J. H. Kim (Titanium Department, Korea Institute of Materials Science (KIMS), Changwon 51508, Republic of Korea)
• 홍재근(한국재료연구원 타이타늄연구실) | J.K. Hong (Titanium Department, Korea Institute of Materials Science (KIMS), Changwon 51508, Republic of Korea)
• 유지훈(한국재료연구원 분말재료연구본부) | J.H. Yu (Powder Materials Division, Korea Institute of Materials Science (KIMS), Changwon 51508, Republic of Korea)
• 이제인(부산대학교 재료공학과) | J.I. Lee (School of Materials Science and Engineering, Pusan National University, Busan 46241, Republic of Korea) Corresponding author