First-principle study of interfacial properties between γ-TiAl and TiC, VN

ABSTRACT

The adhesion, wettability, atomic bonding and electronic structure of γ-TiAl(110)/TiC(100) and γ-TiAl(110)/VN(100) interfaces were performed and investigated using first-principle calculations. Surface energy of γ-TiAl, TiC and VN with low crystal indices was calculated and compared, respectively. The three Al-terminated γ-TiAl(110)/ceramic(100) interface models were investigated to illustrate the interfacial bonding nature. The structure of Al atom placed on the top of the metalloid C and N atoms at the interface is the preferred interfacial structure with the larger work of adhesion. The electronic structure results show that the structure with metalloid site exists with the stronger polar covalent bonding between the interfacial Al and metalloid atom. The interfacial structure with metal site exhibits a mixture of the metallic features with some degree of covalent features. The simulation results are in agreement with the experimental results, in which the γ-TiAl/TiC interface exhibits the better wettability and stronger bonding than the γ-TiAl/VN interface.

KEYWORDS:

• Adhesion
• interfacial characterisation
• γ-TiAl alloy
• ceramics
• first-principle

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number 51704049]; Chongqing Research Program of Basic Research and Frontier Technology [grant number cstc2017jcyjAX0312] and the Fundamental Research Funds for the Central Universities [grant number 106112017CDJXY320002].