Interaction of strain rate and hydrogen input on the embrittlement of 7075 T6 Aluminum alloy

The effect of hydrogen on the mechanical properties of AA 7075- T6 was studied by in-situ hydrogen charging with slow strain rate technique in two aqueous media. A comparative study has been made on the stress-strain curve, time to failure at different strain rates (10−4-10−6 s−1) in the air and by in- situ hydrogen charging. A variable effect of strain rate on embrittlement was observed. The alloy developed a surface film of oxide or hydroxide in the environments tested in spite of cathodic charging. This oxide film interferes with hydrogen embrittlement in the alloy. The kinetics of film formation and consistency of the film were dependent on the environment. At intermediate strain rates the film interfered and reduced hydrogen entry, while at the slowest strain rates hydrogen embrittlement was significant.