Chemical bonding, thermodynamic stability and mechanical strength of Ni3Ti/α-Al2O3 interfaces by first-principles study

• Published in: Scripta materialia Vol. 190; pp. 57 - 62
• Main Authors: Chen, Lu, Li, Yefei, Xiao, Bing, Gao, Yimin, Wang, Juan, Yi, Dawei, Wang, Zhicheng, Zhao, Siyong
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2021
• Subjects: First-principles calculations; Interfacial energy; Ni3Ti/Al2O3 interfaces; Tensile experiment; First-principles calculations; Ni3Ti/Al2O3 interfaces; Interfacial energy; Tensile experiment
• ISSN: 1359-6462; 1872-8456
• DOI: 10.1016/j.scriptamat.2020.08.021

We performed a first-principles calculation to investigate the 85 different Ni3Ti/Al2O3 interfaces. The study shows that the formation of metal-oxygen interfaces and high symmetric interfacial stacking sequences is highly favored both by work of adhesion and interfacial energy. At high temperature and O-poor condition, the metal-metal interfaces show higher thermodynamic stability than metal-oxygen interfaces. The first principles tensile test predicts that the main cause of mechanical failure in Ni3Ti/Al2O3 interface is attributed to the breaking of the Ti-Ni bonds proximity to the interface in the bulk Ni3Ti phase. The interfacial energies of the Ni&Ti-Al2 interfaces at 1000K are increased with the increasing of the partial pressure of oxygen, while for Ni&Ti-O interfaces which are decreasing. [Display omitted]