About the TCS Noble Metal Alloys Database (TCNOBL)

TCS Noble Metal Alloys Database (TCNOBL) is a thermodynamic and properties database developed by Thermo‑Calc software for noble (or precious) metal-based alloys. It is intended for applications in jewelry, dental alloys, decoration industries, and delicate components in scientific instruments. The database includes nearly all stable phases in the assessed systems that may form in as-cast and aged noble-based alloys.

A hybrid approach of experiments, first-principles calculations and CALPHAD modeling are used to obtain thermodynamic descriptions of the constituent binary and ternary systems over the whole composition and temperature ranges. The database is validated against many commercial noble alloys and available experimental information.

TCNOBL4 can be used to calculate various phase diagrams and property diagrams in the assessed systems or even extrapolated higher-order systems. The extrapolation to higher-order systems helps to understand the phase equilibria in multicomponent industrial noble alloys, so as to predict the phase formation, phase fractions and phase compositions or to calculate the driving force of forming a phase. The database can also be used for predicting solidification behavior of noble alloys with the Scheil Calculator in Graphical Mode or the SCHEIL_GULLIVER module in Console Mode.

In addition to thermodynamic data, it has thermophysical properties data available for:

  • Molar volume with thermal expansion coefficients
  • Electrical resistivity
  • Thermal conductivity
  • Viscosity of metallic liquids
  • Surface tension of metallic liquids

TCNOBL4 Thermophysical Properties

The database can be used with our entire suite of products: Thermo-Calc, the Add-on Diffusion (DICTRA), Precipitation (TC-PRISMA), and/or Additive Manufacturing Modules, and all available SDKs.

The thermodynamic database is also compatible with the corresponding mobility database TCS Noble Metal Alloys Mobility Database (MOBNOBL) that provides kinetic data for those working with the add-on kinetic modules – the Diffusion Module (DICTRA) and the Precipitation Module (TC-PRISMA) – as well as a few specific calculation types, such as Scheil with back diffusion. The current version of the mobility database is MOBNOBL2.

TCS Noble Metal Alloys Database (TCNOBL) is also integral to the Noble Metal Alloys Model Library. Noble metal alloys are frequently developed for the purpose of achieving an attractive color. In particular, the Au-Ag-Pt-Cu-Al system is of interest. The Noble Metal Alloys Model Library includes one model, the Optical Properties Model, that was designed for predicting the optical properties and apparent color of noble metal alloys as a function of incident light and other important variables. The model is intended to assist users in achieving an attractive color when developing noble metal alloys for the purpose of cosmetic applications.

The Noble Metal Alloys Model Library is available for free to all users who have the TCS Noble Metal Alloys Database (TCNOBL) (version 3 or newer) and who have a valid Maintenance & Support Subscription (M&SS).

There are examples available to both demonstrate the validation of the database and to showcase the types of calculations that can be used for different materials or application areas such as process metallurgy, heat treatment, and more depending on the database. Sometimes an example is both a validation and a calculation example.

About the Database Examples

Some general use case examples of how the database can be used include the following.

For your actual alloy chemistry, use the database to calculate:

  • Critical transformation temperatures such as solvus temperatures of precipitates, amounts and compositions of phases, solubility limits, activities, phase diagrams.
  • Liquidus, solidus, incipient melt temperatures, freezing range, fraction solid curves, solidification path, fraction eutectic, microsegregation, partition coefficients, latent heat, shrinkage.
  • Thermophysical properties for liquid and solid phases such as volume, density, thermal conductivity/resistivity, and electrical conductivity/resistivity.
  • Liquid properties such as viscosity and surface tension.

Then in combination with the Add on Diffusion Module (DICTRA) or Precipitation Module (TC-PRISMA), which use a compatible mobility database, you can also calculate such things as:

  • Optimal homogenization temperatures, time needed to homogenize any chemical segregation arising from solidification, and/or dissolve precipitates.
  • Concurrent nucleation, growth/dissolution, coarsening of precipitate phases, volume fraction, and size distribution as a function of time.
  • Simulate general diffusion controlled phase transformations with the Diffusion Module (DICTRA)
  • Simulate multi-particle precipitations during aging treatment with the Precipitation Module (TC-PRISMA).

It is possible to combine several databases to make calculations using Thermo‑Calc. For more information related to a specific type of problem, contact one of our support specialists at info@thermocalc.com. The experts are available to make recommendations on the most suitable database to use for your needs.

TCNOBL: TCS Noble Metal Alloys Database Revision History. The current version of the database is TCNOBL4. See the link for any subversion release details.