Hydrogen Trapping in Mg<sub>2</sub>Si and Al<sub>7</sub>FeCu<sub>2</sub> Intermetallic Compounds in Aluminum Alloy: First-Principles Calculations

From first-principles calculations, we estimated the trapping energy of hydrogen atom at the interstitial site of perfect crystals of Mg2Si and Al7FeCu2 intermetallic compounds in the aluminum matrix. We found that Al7FeCu2 trapped hydrogen atoms strongly, whereas Mg2Si did not. The highest trapping energy in Al7FeCu2 is 0.56 eV/atom. We also found that the density of hydrogen trapping can be increased up to about 13 atoms/nm3 while keeping high trapping energy of about 0.40 eV/atom. We inferred that the Al7FeCu2 phase might remove hydrogen from the aluminum matrix, hence, preventing hydrogen embrittlement of aluminum alloy.