Metal Additive Manufacturing Conference 2019

Finite element modelling of Additive processes requires material property data which are not always readily available, especially when using non-standard alloys. CALPHAD tools can calculate properties such as specific heat, density, enthalpy, and mobilities, which can be used as inputs to other codes. These properties are expressed as functions of composition and temperature, which is useful since the additive process can impart large thermal and compositional gradients during a build. More advanced CALPHAD simulations that predict diffusional phase transformation and precipitation behavior can also be used to determine the effect of not only solidification, but also repeated thermal cycling on the final microstructure. As thermal histories will be location specific in a build, these types of simulations can give insight into the local mechanical behavior, when coupled with more advanced structure/property relationships. A few case studies have been highlighted to demonstrate the importance of CALPHAD tools in additive modeling.