Hydrogen trapping and embrittlement in high-strength Al alloys

Abstract Ever more stringent regulations on greenhouse gas emissions from transportation motivate efforts to revisit materials used for vehicles 1 . High-strength aluminium alloys often used in aircrafts could help reduce the weight of automobiles, but are susceptible to environmental degradation 2,3 . Hydrogen ‘embrittlement’ is often indicated as the main culprit 4 ; however, the exact mechanisms underpinning failure are not precisely known: atomic-scale analysis of H inside an alloy remains a challenge, and this prevents deploying alloy design strategies to enhance the durability of the materials. Here we performed near-atomic-scale analysis of H trapped in second-phase particles and at grain boundaries in…