Grain Growth Modeling for Additive Manufacturing of Nickel Based Superalloys

In a laser based additive manufacturing process, the alloy powders undergo a rapid heating, melting, solidification and cooling process. The morphology and the scale of the solidification structure depend on the temperature gradient and the growth rate during the additive manufacturing process. A comprehensive three dimensional transient heat transfer and fluid flow model has been used to calculate the temperature distribution, thermal cycles and local solidification parameters during laser based additive manufacturing process for nickel based super alloys. The growth direction of columnar dendrites and the solidification texture are estimated based on the computed temperature field. The effects of the process parameters on the growth directions, morphologies and scale of the solidification structures are discussed.