Modeling of Effects of Vibration Parameters on Location-Dependent Initial Relative Density in Powder Metallurgy Capsule Filling

Abstract Power Metallurgy Hot Isostatic Pressing (PM-HIP), as a versatile manufacturing process, has the ability to produce net-shape or near-net-shape components with complicated geometries from materials that are not easily cast, deformed, or welded. In PM-HIP, capsule filling is a critical step to get dimensionally and microstructurally sound outputs. Particularly, capsule filling controls the initial relative density (homogeneity) of the PM-HIP compact. In this study, the pre-consolidation capsule filling process is simulated by the Discrete Element Method (DEM); to capture the impact of vibration parameters, including frequency, amplitude, and vibration direction, on the initial Relative Density (RD). The output of the DEM model was imported into a user subroutine-based finite element of PM-HIP containing a combined constitutive model of compressive and consolidative mechanical behavior of powder. The simulation model was used to quantitatively study the relationships between the vibration parameters and the initial RD of the product. The ultimate results of this work show that the optimal initial RD is obtained at the frequency of 60 Hz. The FEA results illustrate that the compact densifies accordingly with respect to the RD and the uniformity of its distribution.