The effect of impurities on the adhesion behavior of TiN(1 1 1)/α-Ti(0 0 0 1) semi-coherent interface: A first-principles investigation

We report quantum mechanical calculations of the effect of impurities on the adhesion between the two TiN/α-Ti materials. The adhesive properties of TiN(1 1 1)/α-Ti(0 0 0 1) interfaces with and without C, N, O, and H impurities were calculated using first principles. Sixteen TiN(1 1 1)/α-Ti(0001) interface models(considering four different terminations and four stacking sites,) were established to investigate the interfacial adhesion characteristics. Among them, the W ad value of the N-terminated interface is much larger than that of the Ti-terminated interface, which is attributed to the strong N-Ti bonding at the interface. Furthermore, the NN-terminated FCC stacking site has an enormous W ad value (7.16 J/m 2 ), so this interface is the optimal structure. At the same time, due to the strong interaction of N-Ti, the B stacking site at the N-terminated interface is transformed into the FCC stacking site after relaxation. In addition, we found that impurity additives can affect the interfacial adhesion in the order of C