Formation of hydrogen blister on AZ91 magnesium alloy during cathodic charging

The process of hydrogen blister formation on as-cast AZ91 magnesium alloy was investigated in 0.1 M NaOH solution using galvanostatic test. The results showed that cathodic charging of AZ91 alloy resulted in hydrogen blister formation, and blister rupture caused the nucleation and propagation of transgranular micro-cracks around the ruptured blister.