Effect of Ce on TiB₂ Interface Behavior in Al-Ti-B-Ce Master Alloy Analyzed by First-Principles

Eight kinds of high symmetry atomic stacking TiB₂(0001)//TiB₂(0001) interface models were sifted and established by first-principles based on density-functional theory. The adhesion work of the interfaces before and after rare earth Ce doping in Al-Ti-B master alloy, and the segregation enthalpy of Ce at the interfaces and the adsorption energy on the TiB₂(0001) surface were calculated. The effect of Ce on the TiB₂ interface behavior was analyzed. The results show that after Ce doping, the adhesion worked of the interface formed by center site stacking two surfaces with two titanium atoms as the terminal and the interface formed by stacking surfaces with titanium atoms as the terminal and with boron atoms as the terminal decreased to promot the dispersed distribution of TiB₂. The segregation enthalpy of Ce at the interfaces was positive, indicating that Ce could not spontaneously segregate to the interface. Ce had high adsorption energy on the TiB₂(0001) surface and could inhibit the stacking growth of TiB₂ on the surface.