IN718 Heat Treatments - Time/Solver Steps
Posted: Tue Sep 05, 2023 8:50 pm
Hello MICRESS Representative,
I am currently running some tests in MICRESS to simulate an additively manufactured (laser beam powder bed fusion, LB-PBF) IN718 specimen accompanied by multiple-step heat treatment processes. For reference, I am using these articles as a starting point: (https://doi.org/10.1016/j.addma.2018.11.024 and https://doi.org/10.1016/j.mtla.2020.100862). I've also been referring to Post #215 (https://board.micress.de/viewtopic.php?f=9&t=563S) for guidance as well.
I can successfully simulate the expected phases during the AM process (e.g., growth of C14_LAVES in the interdendritic regions and NI3TA_D0A near the grain boundaries; I am ignoring the smaller gamma' and gamma'' phases for now).
I'd like to simulate the dissolution of the C14_LAVES phase upon heat treatment; however, the simulations are prohibitively slow given my current parameter choices, and I have yet to have a completed simulation for a single AM cycle followed by a 6hr heat treatment.
I'm guessing that the update interval for molar volume, diffusion coefficients, and nucleation are some of the main reasons for an excessive runtime.
The current values are:
- molar volume TQ update interval: 1e-2
- diffusion coefficients update interval: 5e-3
- nucleation coefficients update interval (same for all nucleation types: C14_LAVES at FCC_L12/LIQUID interface, FCC_L12 at C14_LAVES/LIQUID interface, and NI3TA_D0A in FCC_L12 matrix): 2e-4
For reference, I've attached my current driving file.
The values I have yield reasonable results for the AM portion of the thermal profile, but they appear to be too frequent for the multi-hour heat treatment(s). I could partition the simulation into two: an AM segment and a heat treat segment. However, if possible, I see utility in being able to run a full thermal profile in one simulation. Nevertheless, I do not have a good sense of how to change the parameters for the heat treatment portion.
I am using the temp_limit_phase_TQ option to help speed things up, but the heat treatment sits right in this range.
1) Do you have any recommendations on how to speed up this simulation?
2) Is there a general rule of thumb - or recommendation - for time stepping/updates for long heat treatments? I'm guessing it is generally material-specific, but any insight for this materials system would also be appreciated.
Thank you in advance for your time!
Best regards,
David
I am currently running some tests in MICRESS to simulate an additively manufactured (laser beam powder bed fusion, LB-PBF) IN718 specimen accompanied by multiple-step heat treatment processes. For reference, I am using these articles as a starting point: (https://doi.org/10.1016/j.addma.2018.11.024 and https://doi.org/10.1016/j.mtla.2020.100862). I've also been referring to Post #215 (https://board.micress.de/viewtopic.php?f=9&t=563S) for guidance as well.
I can successfully simulate the expected phases during the AM process (e.g., growth of C14_LAVES in the interdendritic regions and NI3TA_D0A near the grain boundaries; I am ignoring the smaller gamma' and gamma'' phases for now).
I'd like to simulate the dissolution of the C14_LAVES phase upon heat treatment; however, the simulations are prohibitively slow given my current parameter choices, and I have yet to have a completed simulation for a single AM cycle followed by a 6hr heat treatment.
I'm guessing that the update interval for molar volume, diffusion coefficients, and nucleation are some of the main reasons for an excessive runtime.
The current values are:
- molar volume TQ update interval: 1e-2
- diffusion coefficients update interval: 5e-3
- nucleation coefficients update interval (same for all nucleation types: C14_LAVES at FCC_L12/LIQUID interface, FCC_L12 at C14_LAVES/LIQUID interface, and NI3TA_D0A in FCC_L12 matrix): 2e-4
For reference, I've attached my current driving file.
The values I have yield reasonable results for the AM portion of the thermal profile, but they appear to be too frequent for the multi-hour heat treatment(s). I could partition the simulation into two: an AM segment and a heat treat segment. However, if possible, I see utility in being able to run a full thermal profile in one simulation. Nevertheless, I do not have a good sense of how to change the parameters for the heat treatment portion.
I am using the temp_limit_phase_TQ option to help speed things up, but the heat treatment sits right in this range.
1) Do you have any recommendations on how to speed up this simulation?
2) Is there a general rule of thumb - or recommendation - for time stepping/updates for long heat treatments? I'm guessing it is generally material-specific, but any insight for this materials system would also be appreciated.
Thank you in advance for your time!
Best regards,
David