Investigation of the interfacial bonding properties of NiAl-based composites

Abstract

Abstract NiAl-based composites with Ag2Mo2O7 addition were prepared by spark plasma sintering technology. The microstructure and interfacial bonding characteristics of NiAl-based composites were explored, and the wear mechanism was revealed at room temperature. The interfacial bonding properties were analyzed at the molecular level based on molecular dynamics. The results suggest that after sintering, Ag2Mo2O7 transforms into Ag and MoO3 phases, forming NiAl/Ag and NiAl/MoO3 interfaces. Plastic deformation and fatigue wear account for the majority of the wear mechanism in NiAl-based composites at room temperature. The binding energy of the NiAl/Ag interface is about 16% higher than that of the NiAl/MoO3 interface. Among them, the binding energy of the NiAl/Ag interface is 1.759 kcal/mol·Å2, and the binding energy of the NiAl/MoO3 interface is 1.475 kcal/mol·Å2. The fatigue spalling and microcrack of NiAl matrix composites at room temperature are attributed to the poor interfacial bonding properties between NiAl and MoO3.