Aluminium-based alloys

Our CALPHAD-based software and databases allow a high fidelity calculation of phase equilibria in multicomponent Al-based alloy systems and provide an efficient way to design and optimize materials chemistry and processing for obtaining desired microstructure and properties.

By using Thermo-Calc and compatible thermodynamic databases, a vast amount of information can be obtained of relevance for multicomponent Al-based alloys.

Examples of properties that can be predicted:

  • Phase amount and constitution as a function of composition
  • Phase amount and constitution as a function of temperature
  • Liquidus, solidus and other phase transformation temperatures
  • Solubility of alloy elements in Al
  • Partitioning of alloying elements among different phases
  • Enthalpy, heat capacity, driving force for phase nucleation and growth
  • Lattice parameter, density, coefficient of thermal expansion and volume

During casting, welding and joining of Al alloys, the solidification of the alloys happens almost entirely in a non-equilibrium way. The non-equilibrium solidification path can be predicted rather accurately by using the Scheil-Gulliver module available in Thermo-Calc.

From a multicomponent Scheil-Gulliver calculation, one can obtain:

  • Solidification temperature range
  • Incipient melting point
  • Phase amount and its composition
  • Phase formation sequence
  • Micro-segregation of solute elements
  • Latent heat evolution
  • Density variation and volume shrinkage

By using the Diffusion Module (DICTRA) and combining both thermodynamic and kinetic databases, typical diffusion-controlled phase transformations in Al-alloys can be simulated under arbitrary heat treatment conditions.

Examples of applications that can be studied using the Diffusion Module (DICTRA) include:

  • Growth or dissolution of intermetallic phases
  • Cooling effects in solidification
  • Homogenization of as-cast alloys
  • Coarsening of precipitate phases

By using the Precipitation Module (TC-PRISMA) and combining thermodynamic and kinetic databases, the concurrent nucleation, growth and coarsening of precipitates can be simulated.

Precipitation Module (TC-PRISMA) simulation results include the temporal evolution of:

  • Mean radius 
  • Number density
  • Volume fraction
  • Particle size distribution

Thermophysical Properties

The CALPHAD method has recently been extended to model additional thermophysical properties. The most recent version of the TCS Aluminium-based Alloys Database has electric resistivity, thermal conductivity, surface tension of liquid, viscosity of liquid and molar volume included. For more details see the links to the Technical Information and Examples Collection PDFs.