Electronic, Tensile, and Sliding Characteristics of the C/Ti Interface: A First-Principles Study

Abstract

In this paper, according to the C(111) surface and Ti(112̅0) surface relative positions, three stacking interface models were constructed by the first-principles method, and they were defined as 1st-C(111)/Ti(112̅0), 2nd-C(111)/Ti(112̅0), and 4th-C(111)/Ti(112̅0), respectively. After calculation, the work of interfacial adhesion of the 1st-C(111)/Ti(112̅0), 2nd-C(111)/Ti(112̅0), and 4th-C(111)/Ti(112̅0) interface models is found to be 9.689, 10.246, and 9.714 J/m2, respectively, and their interface energies are observed to be 1.064, 0.507, and 1.039 J/m2, respectively. Moreover, the electronic characteristics of C(111)/Ti(112̅0) interfaces are dominated by polar covalent bonds, supplemented by certain metallicity. When the strain reaches 13, 15, and 12%, respectively, the maximum tensile stress values of 1st-C(111)/Ti(112̅0), 2nd-C(111)/Ti(112̅0), and 4th-C(111)/Ti(112̅0) interface models are observed to be 16.207, 19.183, and 17.393 GPa, respectively. After all C(111)/Ti(112̅0) interfaces fracture under tension, the Ti atoms of the Ti(112̅0) surface are transferred to the C(111) surface, indicating that the strength of Ti–C bonds at the interface is higher than the strength of Ti–Ti bonds inside the Ti(112̅0) surface. The maximum value of the sliding potential energy surface is 1.709 J/m2; the maximum value of the potential energy curve is 0.445 J/m2; and the ideal shear strength of the C(111)/Ti(112̅0) interface is 0.386 GPa. In summary, the interfacial adhesion property of the 2nd-C(111)/Ti(112̅0) interface is better than those of 1st-C(111)/Ti(112̅0) and 4th-C(111)/Ti(112̅0) interfaces.

Theoretical study of the effects of alloying elements on TiO2/Ti2AlNb interface adhesion properties

“…The lower the energy consumed by sliding, the worse the interface stability and resistance to tangential separation. 11–14…”

“…The lower the energy consumed by sliding, the worse the interface stability and resistance to tangential separation. [11][12][13][14] For Ti-Al alloys, we studied the stability and oxide adhesion properties of g-TiAl/Al 2 O 3 and g-TiAl/TiO 2 interfaces. [15][16][17][18] By calculating the effects of different stacking forms and relative positions on stability, we found that Al 2 O 3 and TiO 2 tend to combine with Al and Ti atoms on the surface of the g-TiAl alloy, respectively.…”