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为了研究涂层中Ti/TiB _2界面性质,本文采用第一性原理方法计算了Ti(0001)和TiB _2(0001)的表面能,6种不同Ti(0001)/TiB _2(0001)界面的黏附功和界面能,并且分析了它们的电子密度、差分电荷密度和分波态密度(PDOS).研究结果表明,当TiB _2(0001)表面的原子层数n≥9时,其表面深处的原子具有体相原子的特征.在6种不同的界面中,B终端的Ti/TiB_2界面稳定性均优于Ti终端的界面,且B终端的孔穴位堆垛界面(BTH)和Ti终端的心位堆垛界面(TTC)分别是两种终端最稳定的界面.此外,BTH界面具有最大的黏附功(7.72 J/m~2),它在整个Ti元素的化学势(-3.2~0 eV)范围内也具有最低的界面能,说明BTH界面具有最好的稳定性和结合强度.电子性质和PDOS的研究结果表明,BTH界面主要由Ti–B共价键和Ti–Ti金属键构成,且Ti–B共价键是主要由界面处的B 2p和Ti3d轨道杂化所形成的.
In order to study the interface properties of Ti / TiB 2 in the coating, the surface energy of Ti (0001) and TiB 2 (0001) and the surface energy of six different Ti (0001) / TiB 2 (0001) Adhesion work and interfacial energy, and their electronic density, differential charge density and partial density of states (PDOS) were analyzed.The results show that when the atomic number of TiB 2 (0001) surface is n≥9, the surface depth Of the atoms have the characteristics of bulk phase atoms.The Ti / TiB 2 interfacial stability at the B terminal is better than the Ti terminal interfacial between the B terminal and the B terminal hole stacking interface (BTH) The TTC is the most stable interface between the two terminals, respectively. In addition, the BTH interface has the maximum adhesion work (7.72 J / m ~ 2) ), Which shows that the BTH interface has the best stability and bonding strength.The results of electronic properties and PDOS show that the BTH interface mainly consists of Ti-B covalent bond and Ti-Ti metal bond, And the Ti-B covalent bond is formed mainly by the B 2p and Ti 3d orbital hybrids at the interface.