Work

Influence of residual deformation fields on microstructural evolution during powder metallurgy hot isostatic pressing

Year: 2026

Type: article

Abstract: The objective of this study is to understand how deformation fields and residual defects influence microstructure evolution during powder metallurgy hot isostatic pressing (PM-HIP). For this, gas-atomized Fe-10Cr-6.1Al powders are consolidated at 750°C and 1050°C at 100 MPa and 150 MPa for 3 h. The lower consolidation temperature corresponds to a kinetically intermediate stage of PM-HIP evolution, enabling observation of dynamic consolidation mechanisms through parametric effects. Numerous low-angle grain boundaries are observed at intermediate stages of the consolidation process. Results show that strain energy (from entrained low-angle grain boundaries and contact stresses) drives rapid recovery and recrystallization at the early stages of PM-HIP. But as strain energy is dissipated through defect annihilation and relaxation of contact stresses, microstructural evolution slows, and grain growth dominates the later stages of PM-HIP. In PM-HIP microstructure, isolated fine-grained particle artifacts are observed, which remain relatively undeformed, potentially due to delayed recovery-recrystallization kinetics associated with initial microstructure and/or localized stress and strain variations. This work reveals that residual deformation fields, together with PM-HIP processing parameters, can be used to kinetically trap the consolidated microstructure at desired stages along the recovery-recrystallization-grain growth process. Harnessing this concept enables us to design controlled material microstructure through advanced manufacturing.

Source: Materials & Design

DOI: 10.1016/j.matdes.2026.117421