Related Experiment Video
Updated: May 11, 2026
12:37
Phase Diagram Characterization Using Magnetic Beads as Liquid Carriers
Published on: September 4, 2015
Phase separation in ternary Co-Gd-Ti liquids
1IFW Dresden, Institut für Komplexe Materialien, Dresden, Germany. j.han@ifw-dresden.de
Summary
Ternary Co-Gd-Ti alloys exhibit liquid-liquid phase separation, particularly at higher Gd and Ti concentrations. This immiscibility extends from binary Gd-Ti systems into the ternary Co-Gd-Ti phase space.
Area of Science:
- Materials Science
- Physical Chemistry
- Metallurgy
Background:
- Understanding phase equilibria in multi-component systems is crucial for alloy development.
- Ternary Co-Gd-Ti alloys are of interest for potential applications, necessitating detailed phase diagram studies.
Purpose of the Study:
- To investigate the phase equilibria and solidification behavior of ternary Co-Gd-Ti alloys.
- To determine the extent of liquid-liquid phase separation in the Co-Gd-Ti system.
Main Methods:
- In situ studies using electrostatic levitation and high-energy synchrotron X-ray diffraction (XRD).
- Thermodynamic calculations employing the CALPHAD (Calculation of Phase Diagrams) method.
Main Results:
- Direct evidence of liquid-liquid phase separation was observed in molten Co30Gd35Ti35.
- No phase separation was detected in Co30Gd50Ti20.
- Coarsened microstructures, indicative of phase separation, were found in several cast Co-Gd-Ti alloys.
- The stable miscibility gap of binary Gd-Ti extends into the ternary Co-Gd-Ti system up to approximately 30 at.% Co.
Conclusions:
- The stable miscibility gap in the binary Gd-Ti system significantly influences the phase equilibria of the ternary Co-Gd-Ti system.
- Experimental findings are well-supported by CALPHAD thermodynamic calculations, validating the proposed phase boundaries.
More Related Videos
Related Concept Videos
01:28Phase Diagrams of Ternary Systems
Consider a ternary system, which is composed of three components: water (W), ethanoic acid (E), and trichloromethane (T). Here, Ethanoic acid (E) is fully miscible with both water (W) and trichloromethane (T), meaning it can mix entirely with either of them. However, water and trichloromethane have partial miscibility, meaning they can only mix to a certain extent, beyond which two separate phases will form.The phase diagram of a ternary system is represented as an equilateral triangle, where...
01:24Solid–Solid Solutions
The temperature-composition phase diagram of two solids, A and B, which are immiscible in the solid phase but form miscible liquids, shows that when the temperature is low, these two exist as separate, pure solids (A and B). As the temperature increases, they transition into a single-phase liquid solution where A and B coexist. Moving from point a1 to a2 in the phase diagram, the composition changes such that solid B begins to separate from the solution, enriching the remaining liquid with A.
01:19Phase Diagram
The phase of a given substance depends on the pressure and temperature. Thus, plots of pressure versus temperature showing the phase in each region provide considerable insights into the thermal properties of substances. Such plots are known as phase diagrams. For instance, in the phase diagram for water (Figure 1), the solid curve boundaries between the phases indicate phase transitions (i.e., temperatures and pressures at which the phases coexist).
01:24Phase Diagram
A phase diagram is a graphical representation of the physical states of a substance under different conditions of temperature and pressure. It shows the boundaries between solid, liquid, and gas phases and the conditions at which these phases coexist in equilibrium. An area in a phase diagram represents a single phase, whereas lines or phase boundaries represent the equilibrium between two phases.In the phase diagram of water, the boundary line between the solid and liquid states illustrates...
01:27Two Components: Liquid–Liquid Systems
A pressure-composition phase diagram explicitly describes the behavior of an ideal solution of two volatile liquids under varying pressures and compositions. A pressure-composition diagram has two main curves. The bubble point curve represents the plot of pressure versus liquid mole fraction. It indicates the pressure at which the first bubble of vapor forms from the liquid phase as the system pressure decreases.The dew point curve is the pressure versus vapor mole fraction. It indicates the...
02:39Phase Diagrams
A phase diagram combines plots of pressure versus temperature for the liquid-gas, solid-liquid, and solid-gas phase-transition equilibria of a substance. These diagrams indicate the physical states that exist under specific conditions of pressure and temperature and also provide the pressure dependence of the phase-transition temperatures (melting points, sublimation points, boiling points). Regions or areas labeled solid, liquid, and gas represent single phases, while lines or curves represent...