Modeling of Powder Metallurgy Hot Isostatic Pressing and Application to a Ni-Base Superalloy

A finite element (FE) model was developed to simulate the densificationDensification of a nickel-base superalloyNickel-base superalloys powder during the hot isostatic pressingHot isostatic pressing (HIPHot Isostatic Pressing (HIP)) process. A unified material model which simultaneously captures the various deformation mechanismsDeformation mechanisms, such as plasticity and creepCreep, was used in this study. Elaborate experiments were carried out to generate thermal and mechanical propertiesMechanical properties and calibrate the model parameters for an aerospace industry relevant powder alloy. FE simulations of powder encapsulated in a stainless steel canister were performed to evaluate the model capability to capture the canister distortion as well as powder densificationDensification during the HIPHot Isostatic Pressing (HIP) process. The densificationDensification and shape change predictions from the FE model were verified using experimental data obtained from interrupted HIPHot Isostatic Pressing (HIP) runs performed at various temperatures and pressure ramp rates. Good agreement was found between the model predictions and the experimental results. It was found that including the creepCreep response of the canister in the simulation had a significant influence on the capability of the FE model to predict the powder densificationDensification behavior, especially during the hold time at peak pressure. The FE model provided critical insights on mechanical factors leading to non-uniform densificationDensification in the powder compact and canister deformation.