Phase Fraction Contour Diagram for Ti64

Purpose: Learn to calculate and plot phase fraction contour diagram in a multi-component system. In this example, a contour diagram is calculated and plotted for an isopleth in the Ti-Al-V-N-O five components system.

Module: PanPhaseDiagram

Thermodynamic Database: PanTi.pdb(this database is a thermodynamic database for multi-component titanium alloys which is only available to users who have licensed it.)

Calculation Procedures:

Figure 1:  Setup a calculation for an isopleth along Ti-Al side with fixed V, O, and N compositions

  • Click “Contour Lines” in the dialog shown in Figure 1, then set the Contour Type as shown in Figure Figure 2;

Figure 2:  Setup contour lines as the fraction of Bcc (β) phase

Post Calculation Operation:

Information obtained from this calculation:

  • Figure 3 shows the isopleth Ti-Al-4V-0.1O-0.02N (wt%) with contour lines of fractions of the b phase. It clearly shows how the fraction of the b phase varies with temperature and composition. This plot provides a guidance on the selection of alloy composition and heat treatment condition if certain fraction of b phase is needed in the microstructure;

  • For Ti64 (6 wt% of Al as indicated by the black dash line), the fraction of b phase (and a phase) in the a+b two-phase structure can be read from the contour diagram directly given a heat treatment temperature;

Figure 3:  Contour diagram of the b phase fraction on the isopleth of Ti-Al-4V-0.1O-0.02N (wt%)