Microstructure simulations of Inconel 718 during selective laser melting using a phase field model
- 289 Downloads
In this study, the microstructure evolution of the Inconel 718 alloy fabricated by selective laser melting (SLM) was investigated by a phase field model. The temperature gradient and the solidification velocity were first calculated from a finite element thermal model of SLM and then used as the input of the phase field model to simulate the microstructure growth with time. The influences of the build height and laser beam scanning speed on the microstructure evolution were studied and evaluated. The results show that the columnar dendritic arm spacing values estimated from the phase field simulations are comparable to experimental and analytical results. With the increase of the build height, the dominated values of thermal gradient and cooling rate decreased first and then slightly increased at the top end of the manufacturing process. The microstructural evolution along the build height agreed well with the experimental test. In addition, with the increase of the laser beam scanning speed, the dominant temperature gradient increased to a certain value and then decreased, and the direction of the maximum temperature gradient tended to be parallel to the part build direction. Moreover, the temperature gradient affects the dendrite growth significantly, a greater temperature gradient resulting in a higher growth speed.
KeywordsSelective laser melting Powder bed fusion additive manufacturing Inconel 718 Microstructure simulation Phase field method
Unable to display preview. Download preview PDF.
The Marshall Space Flight Center fabricated the experimental samples.
This work was partially supported by the CFD Research Corporation (Huntsville, AL) through a NASA STTR project.
- 4.Ji Y, Chen L, Chen L-Q (2018) Understanding microstructure evolution during additive manufacturing of metallic alloys using phase-field modeling. In: Gouge M, Michaleris P (eds) Thermo-mechanical modeling of additive manufacturing. Elsevier Inc.,Oxford, United Kingdom, pp 93–116Google Scholar
- 11.Cao GH, Sun TY, Wang CH, Li X, Liu M, Zhang ZX, Hu PF, Russell AM, Schneider R, Gerthsen D, Zhou ZJ, Li CP, Chen GF (2018) Investigations of γ′, γ″ and δ precipitates in heat-treated Inconel 718 alloy fabricated by selective laser melting. Mater Charact 136:398–406. https://doi.org/10.1016/j.matchar.2018.01.006 CrossRefGoogle Scholar
- 19.Markl M, Körner C (2016) Multiscale modeling of powder bed-based additive manufacturing. Annu Rev Mater Res 46:93–123. https://doi.org/10.1146/annurev-matsci-070115-032158 CrossRefGoogle Scholar
- 21.Galarraga H, Warren RJ, Lados DA, Dehoff RR, Kirka MM (2017) Fatigue crack growth mechanisms at the microstructure scale in as-fabricated and heat treated Ti-6Al-4V ELI manufactured by electron beam melting (EBM). Eng Fract Mech 176:263–280. https://doi.org/10.1016/j.engfracmech.2017.03.024 CrossRefGoogle Scholar
- 22.Liu D, Wang Y (2017) Mesoscale multi-physics simulation of solidification in selective laser melting process using a phase field and thermal lattice Boltzmann model:V001T002A027. https://doi.org/10.1115/DETC2017-67633
- 23.Tan W, Bailey NS, Shin YC (2011) A novel integrated model combining cellular automata and phase field methods for microstructure evolution during solidification of multi-component and multi-phase alloys. Comput Mater Sci 50:2573–2585. https://doi.org/10.1016/j.commatsci.2011.03.044 CrossRefGoogle Scholar
- 31.Cole JV (2017) Multiple high-fidelity modeling tools for metal additive manufacturing process development, (Research Report)Google Scholar
- 32.Zeng K, Pal D, Stucker B (2012) A review of thermal analysis methods in laser sintering and selective laser melting, pp 796–814 http://sffsymposium.engr.utexas.edu/Manuscripts/2012/2012-60-Zeng.pdf Google Scholar
- 33.Cheng B, Gong X, Xiaoqing W, Chou K (2014) Thermal analysis, microstructural characterization and nanoindentation for electron beam additive manufacturing. The Fourteenth Annual Early Career Technical Conference, Birmingham, pp 196–203Google Scholar
- 35.Karma A (2001) Phase-field formulation for quantitative modeling of alloy solidification. Phys Rev Lett 87(115701). https://doi.org/10.1103/PhysRevLett.87.115701
- 36.Provatas N, Elder K (2011) Phase-field methods in materials science and engineering. WileyGoogle Scholar
- 38.Keller T, Lindwall G, Ghosh S, Ma L, Lane BM, Zhang F, Kattner UR, Lass EA, Heigel JC, Idell Y, Williams ME, Allen AJ, Guyer JE, Levine LE (2017) Application of finite element, phase-field, and CALPHAD-based methods to additive manufacturing of Ni-based superalloys. Acta Mater 139:244–253. https://doi.org/10.1016/j.actamat.2017.05.003 CrossRefGoogle Scholar
- 45.Kou S (1987) Welding metallurgy, New YorkGoogle Scholar
- 52.AlMangour B et al (2018) Thermal behavior of the molten pool, microstructural evolution, and tribological performance during selective laser melting of TiC/316L stainless steel nanocomposites: experimental and simulation methods. J Mater Process Technol 257:288–301. https://doi.org/10.1016/j.jmatprotec.2018.01.028 CrossRefGoogle Scholar
- 55.Nastac L, Valencia JJ, Tims ML, Dax FR (2001) Advances in the solidification of IN718 and RS5 alloys. Proc Superalloys 718:625–706. https://doi.org/10.7449/2001/Superalloys_2001_103_112 Google Scholar