AlSi10Mg - Nucleation of Diamond and Mg2Si at high cooling rates
Posted: Tue Jun 22, 2021 10:52 am
Hi everyone,
I set up a simulation for AlSi10Mg alloy. I want to simulate the dendritic growth of the FCC (in my simulation: fraction 1) and the Diamond (fraction 2) and Mg2Si-phase (fraction 3) with high cooling rates as they occur during laser powder bed fusion. Below I describe my simulation set-up.
My simulation domain is 200x1x200 and I simulate with a grid resolution of 0.01 µm. I use a rectangular grain as starting grain. The used Thermo-Calc-file and the input-file of my simulation are attached.
I started to optimize the numerical parameter to set up a simulation that works with the huge cooling rate and without the nucleation of the Diamond and Mg2Si phase as described in:
https://board.micress.de/viewtopic.php? ... ates#p3197
After that, I tried to nucleate the Diamond phase at the interface and the Mg2Si-phase in the bulk. I was able to nucleate the two phases. I enabled "moving frame" to move my simulation box and speed up my simulation.
The dendrites look realistic at the beginning. The driving force of the dendrite tip is constant over time. The Diamond phase nucleates at the interface with higher simulation time:
In the end of the simulation, where I expect complete solidification, there is still liquid present. I am not sure if the temperature profile is correct. I expected dendrites with a eutectic structure in bulk. I think that the simulation is not valid yet regarding the numerical or nucleation parameters:
In the complete output when "out moving frame" is active there is also seen liquid between the dendrites. Is this output a stitching of the single pictures of the moving frame or is the area outside of the moving frame also simulated?
I tried to increase my simulation box without a moving frame to simulate the growth of the Diamond- and Mg2Si-phase, but it led to a very long simulation time.
Thanks for your help!
Johannes
I set up a simulation for AlSi10Mg alloy. I want to simulate the dendritic growth of the FCC (in my simulation: fraction 1) and the Diamond (fraction 2) and Mg2Si-phase (fraction 3) with high cooling rates as they occur during laser powder bed fusion. Below I describe my simulation set-up.
My simulation domain is 200x1x200 and I simulate with a grid resolution of 0.01 µm. I use a rectangular grain as starting grain. The used Thermo-Calc-file and the input-file of my simulation are attached.
I started to optimize the numerical parameter to set up a simulation that works with the huge cooling rate and without the nucleation of the Diamond and Mg2Si phase as described in:
https://board.micress.de/viewtopic.php? ... ates#p3197
After that, I tried to nucleate the Diamond phase at the interface and the Mg2Si-phase in the bulk. I was able to nucleate the two phases. I enabled "moving frame" to move my simulation box and speed up my simulation.
The dendrites look realistic at the beginning. The driving force of the dendrite tip is constant over time. The Diamond phase nucleates at the interface with higher simulation time:
In the end of the simulation, where I expect complete solidification, there is still liquid present. I am not sure if the temperature profile is correct. I expected dendrites with a eutectic structure in bulk. I think that the simulation is not valid yet regarding the numerical or nucleation parameters:
In the complete output when "out moving frame" is active there is also seen liquid between the dendrites. Is this output a stitching of the single pictures of the moving frame or is the area outside of the moving frame also simulated?
I tried to increase my simulation box without a moving frame to simulate the growth of the Diamond- and Mg2Si-phase, but it led to a very long simulation time.
Thanks for your help!
Johannes