Fatigue and fracture behavior of aluminum alloys in gaseous hydrogen

Fatigue and fracture properties of aluminum alloys do not appear to degrade in the presence of dry gaseous hydrogen, based on limited available data. However, more data are needed, particularly at higher hydrogen pressure and for higher strength grades, to reliably suggest broader use of aluminum alloys for hydrogen applications. In this study, we investigate the effect of gaseous hydrogen on fatigue and fracture behavior of four aluminum alloys: 5083, 2219, 7050, and 7475. Fatigue crack growth behavior of these alloys is investigated in air and in gaseous hydrogen at pressure of 1,000 bar. In addition, the fracture resistance of each alloy was determined in these environments. Results showed that gaseous hydrogen did not have a detrimental effect on either fatigue crack growth rate or fracture resistance of these aluminum alloys for the tested conditions. Interestingly, the fatigue and fracture properties showed a slight improvement in high-pressure gaseous hydrogen, which may be attributed to the absence of moisture.