Page 39 - MSAM-4-3

Materials Science in Additive Manufacturing Numerical simulation of plasma WAAM for Ti-6Al-4V

A B

C D

Figure 7. Plasma-based wire arc additive manufacturing simulation and mechanical behavior of a Ti-6Al-4V single-walled structure. (A) Numerical model
of the single wall structure. (B) Total displacement of the wall after cooling and unclamping the top surface. (C) Top surface out-of-plane distortion along
the longitudinal direction. (D) Bottom surface out-of-plane distortion along the longitudinal direction .
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role in defining the final part’s structural integrity and A numerical model using Simufact Welding 8.0 was
performance. developed to predict the thermal behavior of weld beads,
To evaluate the applicability of the calibrated single- and experimental data were used for model verification
bead model to more realistic build scenarios, Bielik et al. and heat source calibration. The results contribute to the
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extended the numerical simulation framework to a multi- optimization of structural welding simulations and the
layer deposition scenario, representative of realistic WAAM improvement of predictive modeling in AM. The main
components. The thermal model was adapted to simulate conclusions of this study are as follows:
the deposition process and to predict the distortion fields (i) The Goldak double-ellipsoid heat source model
for a complete wall structure using Simufact Welding, as effectively represents the experimentally determined
shown in Figure 7. The previously derived and calibrated conditions, demonstrating its suitability for structural
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heat source parameters and thermal coefficients remain welding simulations. However, improved temperature
unchanged, with only the deposition trajectory modified measurement techniques, including shielded
to reflect the multi-pass nature of the wall geometry. thermocouples, advanced mounting methods,
higher-frequency data logging, real-time weld pool
Further studies are needed to assess the correlation monitoring, and data-driven algorithms, are required
between the thermal and geometric evolution of the to improve calibration accuracy.
WAAM parts during multi-layer deposition (aerospace (ii) The simulation results successfully reproduce the
structures, cylindrical, and nonlinear structures ). In temperature distributions, with predictions of
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addition, there is an increasing shift toward material the melt zone and HAZ in close agreement with
deposition along arbitrary paths, enabling the modeling experimental measurements. However, discrepancies
and fabrication of complex metal structures with greater arise due to uncertainties in heat source calibration,
precision and predictability. simplifications in bead geometry modeling, and
assumptions in boundary conditions, highlighting the
5. Conclusion need for further refinement.
This study presents a comprehensive methodology for (iii) The effectiveness of the trial-and-error method
calibrating the Goldak double-ellipsoid heat source model depends on the expertise of the user, which introduces
in plasma-based WAAM of Ti6Al4V single-track welds, variability in results. This approach to parameter
integrating FE simulations and experimental validation. tuning is case-specific and requires recalibration for

Volume 4 Issue 3 (2025) 12 doi: 10.36922/MSAM025140021