Hot Corrosion Behavior of Ti₃Al Intermetallics in LiCl-Li₂O Molten Salt

The hot corrosion behavior of Ti3Al intermetallics in molten LiCl-Li2O was investigated with immersion experiment.Ti3Al showed much better corrosion resistance than 310SS stainless steel in molten LiCl-3%Li2O at 750℃.In molten LiCl-3%Li2O,Ti3Al exhibited a fast corrosion at the initial stage of corrosion,and then kept a steady state with a slow corrosion rate.The corrosion scale showed a bilayered structure of a thicker outer layer of aluminum oxides (LiAlO2,Al2O3) and a thinner compact inner layer of titanium oxides (Li2TiO3,TiO2).The fast corrosion in the beginning of corrosion was due to the selective oxidation of Al,and the slower corrosion rate at the latter stage of corrosion was owing to the formation of protective inner layer of titanium oxides.