Hydrogen Trapping in Mg₂Si and Al₇FeCu₂ Intermetallic Compounds in Aluminum Alloy: First-Principles Calculations

抄録

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.