Study of Interfacial Wetting Behavior of Yttrium Stabilized Zirconia Polycrystalline Ceramics Brazed with AgCuTi Brazing Material Based on First Principles

Differences exist in understanding the formation process of interfacial reaction products between Y-TZP ceramics and reactive brazing materials, and the mechanism of interfacial reaction on the ceramic side remains unclear. To study the brazing interface reaction mechanism of active solder and Y-TZP ceramics, we established the reaction wetting interface model of yttrium stabilitetragonal zirconia (Y-TZP) ceramics brazed by AgCuTi, and we calculated the adhesion work, interfacial energy, and electronic structure of the reactive wetting interface using first principles. The results show that the bonding strength between the Ti and Y-TZP ceramic O termination surface is the highest (work of adhesion (Wad) is 5.108 J/m²), and charge transfer occurs between the Ti and O atoms, which makes the Ti-d and O-p orbitals hybrid. Additionally, a small part of Ti-p/d and O-s interact to form Ti-O ion covalent bonds, forming Ti-O compounds (Ti₂O, TiO). In the interface formed by wetting reaction products (Ti₂O, TiO) and Ag-based solders, both interface energies are far lower than the interface energies of Y-TZP and Ag, in which the bonding ability of Ti₂O(0001)/Ag(111)-Ti(1) is as high as 3.018 J/m². The interface energy is also lower, and the Ti-d orbital of the Ti₂O termination surface interacts with the Ag-d orbital to form a Ti-Ag metal bond, which reduces the interface energy. The Ti₂O compounds generated are more conducive to improving the wettability of the Y-TZP interface.