Solutions for Zirconium
Calculate the following based on your actual alloy chemistry:
Thermophysical properties, such as:
Specific heat, enthalpy, latent heat, density as a function of temperature, coefficients of thermal expansion, viscosity, and surface tension of liquid
Phase based properties, such as:
Critical transformation temperatures (including their sensitivity to oxygen), amounts and compositions of phases, solubility limits, activities, phase diagrams, and more
Equilibrium and non-equilibrium solidification, such as:
Liquidus, solidus, incipient melt temperatures, freezing range, fraction solid curves, solidification path, fraction eutectic, microsegregation, partition coefficients, latent heat, shrinkage, and more
Oxygen Impact on Phase Equilibria and Transition Temperatures
Oxygen is one of the major impurities in Zr-based alloys and has a strong influence on the α/β transus temperature and corresponding phase compositions. Thermo-Calc can be used to predict the sensitivity of varying amounts of oxygen on the α/β transus temperature for different alloy chemistries.
The figure here shows a comparison of calculated values with experimental data of HUN where α+β →β transition temperatures were measured at different oxygen levels in the Zr-rich region. As can be seen, the calculation results are in good agreement with the experimental ones.
Hydrogen Impact on Phase Equilibria and Transition Temperatures
The oxidation of zirconium by water releases hydrogen gas, which partly diffuses into the alloy. As this occurs, an increase of hydrogen in solid solution results in a lowering of the α/β transus temperatures and, if the solubility limit is exceeded, also leads to the formation of zirconium hydrides. These hydrides are less dense and are weaker mechanically than the alloy and so their formation results in blistering and cracking of the cladding – a phenomenon known as hydrogen embrittlement.
Thermo-Calc can be used to predict the sensitivity of different alloy chemistries to hydrogen, as can be seen in the figure here, which shows the calculated H solubility in HCP_Zr compared with published experimental data from Zuzek et al. (Bulletin of Alloy Phase Diagrams, 1990).
Incorporating Insights from First-principles into Calphad Descriptions of Atomic Ordering
Using the ultra-high temperature ceramic zirconium carbide as an example, this talk shows how first-principles calculations can unveil the mechanisms of ordering throughout its wide non-stoichiometry from 0 K up to the maximum melting point of 3700 K, incorporating these insights into a CALPHAD description.
Learn more about Applications to Zr-based Alloys
A collection of examples that demonstrate the validity and calculation abilities of the TCZR database.