|About this Abstract
||Materials Science & Technology 2020
||Phase Transformations in Additively Manufactured Materials
||Effects of Laser Powder Bed Fusion Parameters and Heat Treatment
on Microstructure and Mechanical Behavior of Inconel 718 Alloy
||Thinh Huynh, Abhishek Mehta, Sharon Park, Holden Hyer, Le Zhou, Devin D Imholte, Nicolas E Woolstenhulme, Daniel M Wachs, Yongho Sohn
|On-Site Speaker (Planned)
Excellent weldability and high temperature stability make IN718 one of the most desired alloys to be additively manufactured via laser powder bed fusion (LPBF). In this study, gas-atomized IN718 powders were used to fabricate IN718 samples by LPBF with independently varied laser power (125 - 350W), scan speed (200 - 2200 mm/s), and scan rotation (0 - 90°). In general, relative density greater than 99.5% was accomplished using the energy density range of 50-100 J/mm3; furthermore, a larger processing window was observed at higher laser power. Microstructural features including key holes, lack of fusion flaws, melt pool geometry and grain structure were documented and correlated to the LPBF parameters explored. Various heat treatments were carried out to observe the effects of solutionizing on the formation of δ-phase, the γ' and γ" precipitation, and mechanical properties of LPBF IN718 after the two-step aging process.