Dynamics of pore formation during laser powder bed fusion additive manufacturing. Journal Article uri icon

Overview

abstract

  • Laser powder bed fusion additive manufacturing is an emerging 3D printing technique for the fabrication of advanced metal components. Widespread adoption of it and similar additive technologies is hampered by poor understanding of laser-metal interactions under such extreme thermal regimes. Here, we elucidate the mechanism of pore formation and liquid-solid interface dynamics during typical laser powder bed fusion conditions using in situ X-ray imaging and multi-physics simulations. Pores are revealed to form during changes in laser scan velocity due to the rapid formation then collapse of deep keyhole depressions in the surface which traps inert shielding gas in the solidifying metal. We develop a universal mitigation strategy which eliminates this pore formation process and improves the geometric quality of melt tracks. Our results provide insight into the physics of laser-metal interaction and demonstrate the potential for science-based approaches to improve confidence in components produced by laser powder bed fusion.

publication date

  • April 30, 2019

Full Author List

  • Martin AA; Calta NP; Khairallah SA; Wang J; Depond PJ; Fong AY; Thampy V; Guss GM; Kiss AM; Stone KH

Other Profiles

Additional Document Info

start page

  • 1987

volume

  • 10

issue

  • 1