Co-precipitation of γ' and γ'' in Ni-Al-Nb Ternary

Purpose: Learn to calculate co-precipitation of γ' and γ'' for an alloy in a pseudo-ternary system.

Module: PanEvolution

Thermodynamic and Mobility Database: NiAlNb_Pseudo.tdb

Kinetic Parameters Database: Ni-2.4Al-3.8Nb.kdb

Batch file: Example_#3.3.pbfx

Create a workspace and select the PanEvolution module following Pandat User's Guide: Workspace ;
Load NiAlNb_Pseudo.tdb following the procedure in Pandat User's Guide: Load Database ;
Click on PanEvolution/PanPrecipitation on the menu bar and select "Load KDB or EKDB", then select the Ni-2.4Al-3.8Nb.kdb; the pop-out window is shown in Figure 1 which include the alloy name, the matrix phase and the precipitates. Two precipitates are defined in this case. The phase name in the kdb file is L12_Fcc and gamma_double_prime for γ' and γ'', respectively;
Open the Ni-2.4Al-3.8Nb.kdb from Pandat™ workspace through the menu "File → Open File", and view the kinetic parameters as shown in Figure 2;
Click on the menu "PanEvolution/PanPrecipitation → Precipitation Simulation", and set up the calculation condition as shown in Figure 3.

Figure 1: Pop-out window when loading the Ni-2.4Al-3.8Nb.kdb

Figure 2: Open the Ni-2.4Al-3.8Nb.kdb in Pandat™ workspace to view the kinetic parameters of the two precipitate phases

Figure 3: Precipitation simulation of alloy Ni-2.4Al-3.8Nb ageing at 790 °C for 10h

The default plot shows the total volume fraction of γ' (L12_Fcc) and γ'' as a function of time shown in Figure 4.
Open the Default Table, create time vs sizes of γ' and γ'' phases plots as shown in Figure 5;
Change graph appearance following the procedure in Pandat User's Guide: Property;
Add legend for graph following the procedure in Pandat User's Guide: Icons for Graph on Toolbar;

Figure 4: Default plot showing the volume fraction evolution of the two precipitate phases

Figure 5: Calculated average size evolution of the two precipitate phases

Figure 4 shows the calculated evolution of volume fraction of the two precipitate phases. It is seen that γ' precipitated quickly at very early stage, but gave way to γ'' at later time;
Figure 5 shows the calculated evolution of the average size of the two precipitate phases. It is seen that γ'' is bigger than γ';
Add a new table as shown in Figure 6 with the "Table Type" as psd. The Columns are particle sizes and number densities with (@*) means all precipitate phases. The default calculated size is in meter, which is converted to nm by multiplying the column by 1e+9. The default calculated number density is number/m³, which is converted to mol/m₃ by multiplying 1/6.02e+23. The inde x = i means to populate the size and number density at the final state t=10 h;
Plot particle size distribution from the new table by selecting the particle size as x-axis and number density as y-axis. Plot it for L12 (γ') phase first and then add the one for γ'' as shown in Figure 7.

Figure 6: Create a new table with particle sizes and number densities at final stage

Figure 7: Particle number densities of γ' and γ'' at final stage