HYDROGEN TRAPPING AND HYDROGEN EMBRITTLEMENT OF MAGNESIUM ALLOYS

This study examines hydrogen charged AZ91 and AZ31 magnesium (Mg) alloys with respect to hydrogenation/dehydrogenation process and hydrogen embrittlement. Mg alloys are susceptible to hydrogen embrittlement which can leads to a serious degradation in mechanical properties. We study and compare between the effect of different Mg microstructure, and especially the effect of intermetallic b-Mg₁₇Al₁₂ phase, on the formation, stability, content, and binding energy of MgH₂.

Thermal desorption analysis was used to evaluate activation energies with traps. The reverse hydride reaction was proved to be highly dependent on b- phase. The negative effect of b-phase was clearly shown for promoting hydrogen embrittlement process in addition to preventing the dehydriding process.