Diffusion Simulation with Composition Profile Input

In this tutorial, the Fe-Ni-Cr alloy is taken as an example to demonstrate a diffusion simulation with a composition profile input. The format of input file is discussed in Section Set Initial Composition Profile. The database file mentioned in this section, “FeCrNi.tdb”, can be found in the installation folder of Pandat™. In general, user should follow the following steps to carry out a diffusion simulation:

Set up Initial Condition for Diffusion Simulation

Figure 1 demonstrates the conditions of this simulation. The initial composition profile from the input file is displayed in this figure. The length of the profile is 200 μm and is discretized to 100 grids.

To set the above conditions in PanDiffusion, click through on the tool bar, or from the menu “PanDiffusion→ Diffusion Simulation” a popup window as shown in Figure 2 in Section Diffusion Couple with Uniform Composition Input will allow user to set up calculation conditions. In Figure 2, “Region_2” is deleted firstly. Please refer to Section Delete or Add a Region on how to delete a region. In the remaining “Region_1”, select “input_file” from “Region Composition Distribution”, and click “Browse” to load a .dat (or .txt) file which contains composition profile. Annealing time (100 hours in total) and annealing temperature (1200 °C) are set. Add an intermediate output at 10 h in the “Moments of Profile Outputs” to observe simulation process. Please refer to Section Add Moments for Profile Outputs on how to add a moment of profile output.

Simulation Results

Click OK button in Figure 2 to start the simulation after the initial condition is set properly. The simulation result is displayed in Figure 3. Please refer to Section Graph of this user manual to add text, legend, and change the appearance of the figure.

As is seen in this figure, the initial serrated composition profiles were smoothed out after 10 hours of annealing at 1200 °C, and the material is homogenized after 100 hours of annealing.