In this study, we synthesized three low-sulfur and low-phosphorus ionic liquids (ILs). These were N 88816P 8, P 88816P 8, and P 88816DOSS. The viscosity and thermal stability of the three ILs were analyzed. The tribological properties and lubrication mechanisms of the three ILs were investigated as lubricants for a carbide ball–Inconel 690 nickel-based alloy friction pair and compared at 50 °C and 150 °C. The wear spots of the carbide ball and nickel-based alloy disc samples were characterized using SEM and EDS. The experimental results revealed that P 88816P 8 had excellent tribological properties. The lubrication mechanism of P 88816P 8 as a lubricant for the carbide ball–Inconel 690 nickel-based alloy friction pair was investigated using XPS. The excellent friction reduction and anti-wear properties of P 88816P 8 could be attributed to the tribo-chemistry between P 88816P 8 and Inconel 690 as well as the formation of a tribo-film on the wear-spot surface. This high-performance IL, suitable for carbide ball–Inconel 690 contact, will be applied to a cutting process of Inconel 690.