Binary System Examples
The following plot examples using the TCS High Entropy Alloys Database (TCHEA) and for the Co-Cr, Co-Ni, Nb-Ti, and Fe-Ru binary systems show phase stabilities in the composition-temperature region. It can be used to guide the design of the compositions of BCC, FCC, and HCP medium- (MEA) or high- (HEA) entropy alloys and the relevant heat treatments.
The CALPHAD Method and the Thermo‑Calc Databases. Also visit the video tutorials on our website or our YouTube playlist.
When working in Thermo‑Calc with binary diagrams you use either the Binary Calculator (in Graphical Mode) or the Binary module (in Console Mode). The fundamental calculation engine is the same but you access the settings in different ways.
Co-Cr
The primary phase shifts from FCC in the Co-side to BCC in the Cr-side. The sigma phase is stable in the middle of this binary. The HCP phases are stable at low temperatures in Co-rich side.
Figure 1: The Co-Cr binary phase diagram.
Co-Ni
The primary phase is FCC in the whole composition range. It is stable in a wide temperature range.
Figure 2: The Co-Ni binary phase diagram.
Nb-Ti
The primary phase is BCC in the whole composition range. It is stable in a wide temperature range.
Figure 3: The Nb-Ti binary phase diagram.
Fe-Ru
The primary HCP phase has a wide composition and temperature range extending from the Ru-side.
Figure 4: The Fe-Ru binary phase diagram.