Microscale mechanisms of Hydrogen embrittlement in high strength aluminium

Hydrogen embrittlement (HE) in aluminium alloys is so poorly understood that the latest generation of materials are being removed from service in aerospace applications and routinely replaced with previous generation materials at huge cost to the aviation industry. Measuring crack velocity is a key aspect of quantifying the behaviour of HE cracks but assuming a constant crack velocity whilst useful in an engineering sense is a massive oversimplification and ignores the microstructural scale interactions which must be understood to have the correct context for the fundamental understanding of the mechanisms. Temporary arrest and bursts of growth are clearly occurring, but this has never been directly observed. We will collect multi-temporal microscale 3D images on a timescale of seconds (for 1-10 mins) and at ~hourly intervals to observe the local crack growth behaviour and interaction with the microstructure. We will apply our new crystal plasticity phase field model to this data.