Computational Modeling Approach for Powder Metallurgy of Superalloys Using Continuum Formulations

Thermal properties of powder material/particulate media differ significantly from bulk/wrought continuum properties. Preheating and sintering of nickel-based superalloy powders can take place for several hours depending on homogenization, densification and green strength required for further processing and application. A lot of complexities arise during powder metallurgy (P/M) processing due to the presence of prior particle boundaries (PPBs) and porosity in the material. Finite element simulations for these long thermal cycles are thus, complex and time consuming due to the instabilities that arise during deformation modeling. This paper provides a computational interrogation of these complex powder processing systems in a continuum formulation designed ideally for wrought materials using finite element software DEFORM ™ by modifying thermal parameters based on theoretical relationship linking bulk properties to powder as a function of density. Comparisons are done between fully dense/wrought superalloys with powder thermal properties and porous/powder superalloys with bulk/wrought thermal properties to analyze the effect of these parameters on functioning of computational model. Results can be used to understand and further develop knowledge for P/M modeling and processing.