Materials selection

Deciding which materials to use for a particular application is often based on the material’s properties, performance, suitability for use in the given operational environment, compatibility with other materials and cost. In recent years there has been a shift to consider designing materials with the properties needed for a particular application.

A computational approach can give a large insight into these questions.

Some examples include:

Thermo-Calc

  • Optimising the composition of a material to give the required microstructure in terms of amounts of phases formed, e.g. precipitation hardening phases, while balancing this against other property requirements.
  • For Duplex materials, identifying chemistries that give the required microstructure.
  • For joining dissimilar materials, predicting the phases that could form at the interface.
  • Predicting the long term stability of a material, the formation of life limiting phases and corrosion products under operational conditions.
  • Considering reactions between a material and its containment, e.g. liquid – crucible reactions in a ladle.

Diffusion module (DICTRA)

  • For dissimilar joins (for example, a coating and substrate, or two alloys joined together) predicting the diffusion kinetics and driving forces that give rise to material interactions at the interface and thus predicting phase changes, the growth kinetics of the phases formed, the changes in bulk alloy compositions due to the diffusion process, etc.