Consolidation and Distortion Modeling for a Large AM + PM-HIP Component

Powder metallurgy hot isostatic pressing (PM-HIP) is an advanced manufacturing process capable of producing complex near net shaped parts with homogeneous microstructure and excellent material properties. Adoption of the process, which involves filling a hollow pre-form (a HIP capsule/can) with metal powder and consolidating under pressure at elevated temperatures, has been somewhat limited to niche component applications due to costs associated complex can fabrication and the iterative nature of the capsule design process. HIP capsules are conventionally fabricated via traditional sheet forming operations and welding, which is time consuming, susceptible to process variability, and limiting in terms of part geometric complexity that can be considered. To overcome these limitations, additive manufacturing (AM) is being explored as a way to expedite this process and expand the design envelope of part geometries that can be produced using PM-HIP. The iterative design of a PM-HIP capsule, to properly account for the large non-uniform volumetric shrinkage inherent to the process, can be done either experimentally or computationally, with the latter being preferable for cost and schedule efficiency. This talk highlights recent efforts related to the fabrication of a large (>900 lb) AM+PM-HIP impeller geometry via wire-arc DED and computational modeling of the component distortion during PM-HIP.