Study of Acceptance Criteria and Good Practices to Follow During Powder Handling to Limit Hydrogen Trapping in Aluminium Alloy During Laser Beam Melting Process

摘要

On granular non-reactive material, humidity rate can impact the ability of the powder to be spread in the Laser Beam Melting machines. Furthermore, previous publications on reactive aluminium alloy shew critical defects emergence due to moisture while using external welding for AM parts assembly. We show in this presentation results coming from an additive manufacturing project focused on better understanding of the phenomena occurring when aluminium powder is in contact with moisture. Indeed, in these conditions, aluminium powder seems to undergo hydration effect which makes it difficult to attempt any powder recovery by drying treatment afterward. To do so, we compared behaviours of aluminium alloy with stainless steel powder stored under similar conditions. The final goals of this study are to establish acceptance criteria and good practices to limit contamination problem of aluminium alloys due to humidity while powder handling during all LBM workflow.