Oxide-reduction Strategies To Improve Ductility Of Components Manufactured Via Hot Isostatic Pressing (HIP)

Abstract

Powder metallurgy–hot isostatic pressing (PM-HIP) offers a promising route for producing large, flight-critical landing-gear components in low alloy steels such as 300M. Early development work has shown that although tensile strength targets can be achieved, ductility and toughness can be limited by oxide networks located at prior particle boundaries (PPBs). To address this, the Manufacturing Technology Centre (MTC) investigated two oxide-reduction strategies aimed at improving powder cleanliness prior to HIP consolidation: hydrogen purging during hot degassing, and fluidised bed reactor processing in collaboration with Phoenix Scientific Industries Ltd. Trials were performed on powders with differing initial oxide levels to evaluate process robustness and industrial applicability. Both approaches successfully reduced surface oxides and mitigated PPB formation in HIP-consolidated material, demonstrating their potential to enhance mechanical performance and enable powder recovery routes. These findings support the development of more sustainable, resilient supply chains for PM-HIP components in aerospace applications.