Orientation relationships and interface structure between Al₁₁Ce₃ and Al in Al–Ce eutectic

Al–Ce eutectic alloy has attracted much attention due to its excellent heat resistance and castability. A large number of interfaces are contained in the Al–Ce eutectic alloy. As an intermediary connecting the aluminum matrix and the Al₁₁Ce₃ reinforcement phase, the interfaces play an important role in enhancing the strength and toughness of the alloy. In this paper, eutectic Al–Ce alloy was prepared, the orientation relationship at the Al₁₁Ce₃/Al interface and the interface structure were investigated. Classification of orientation relationship was proposed, and three orientation relationships were observed: OR1, [010]_Al11Ce3//[001]_Al, (00 1¯)_Al11Ce3//(010)_Al, (100)_Al11Ce3//(1¯ 00)_Al; OR2, [5 2¯ 0]_Al11Ce3//[1 2¯ 1]_Al, (001)_Al11Ce3//(111)_Al; OR3, [1¯ 13]_Al11Ce3//[011]_Al, (110)_Al11Ce3//(100)_Al, of which OR3 is a new orientation relationship reported for the first time. First-principle calculations suggest that Al₁₁Ce₃ is combined with Al through a Ce-terminated surface of (001)_Al11Ce3. The electronic structure indicates that the interface between Al and Al₁₁Ce₃ are chemical adsorptions, and the two-phase interface has strong interaction. The strong interface between the reinforcing phase and Al matrix can effectively enhance the load transfer, thereby improving the strength of the material.