Modeling of heat transfer, fluid flow and solidification microstructure of nickel-base superalloy fabricated by laser powder bed fusion
- The Ohio State Univ., Columbus, OH (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- The Ohio State Univ., Columbus, OH (United States)
Laser-Powder Bed Fusion (L-PBF), an additive manufacturing process, produces a distinctive microstructure that closely resembles the weld metal microstructure but at a much finer scale. The solidification parameters, particularly temperature gradient and solidification rate, are important to study the as-built microstructure. In the present paper, a computational framework with meso-scale resolution is developed for L-PBF of Inconel® 718 (IN718), a Ni-base superalloy. The framework combines a powder packing model based on Discrete Element Method and a 3-D transient heat and fluid flow simulation. The latter, i.e., the molten pool model, captures the interaction between laser beam and individual powder particles including free surface evolution, surface tension and evaporation. The solidification parameters, calculated from the temperature fields, are used to assess the solidification morphology and grain size using existing theoretical models. The IN718 coupon built by L-PBF are characterized using optical and scanning electron microscopies. Finally, the experimental data of molten pool size and solidification microstructure are compared to the corresponding simulation results.
- Research Organization:
- The Ohio State Univ., Columbus, OH (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE; Office of Naval Research (ONR) (United States)
- DOE Contract Number:
- AC05-00OR22725; N00014-14-1-0688
- OSTI ID:
- 1394135
- Journal Information:
- Additive Manufacturing, Vol. 12, Issue B; ISSN 2214-8604
- Publisher:
- Elsevier
- Country of Publication:
- United States
- Language:
- English
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