Abstract: The self-made high-temperature oxidation experimental device was used to analyze and compare the color decay of oxidized oil at high temperature of domestic and imported aviation lubricants. The mechanism of inhibiting color decay was discussed by GC/MS. The experimental results showed that the antioxidant Tz516 was an important factor influencing the color blackening of the domestic aviation lubricant. The addition of the phenolic antioxidant T501 could effectively inhibited the color blackening of oxidized oil caused by the amine antioxidant Tz516. As the amount of T501 is gradually increased, a large number of T501 antioxidant molecules occupied a "predominant" position in the oxidation system and consumed most of the free radicals, resulting in a decrease in the number of free radicals reacting with the antioxidant Tz516. It is concluded that the competitive mechanism of antioxidants affects the inhibiting color decay process of oils.

Key words: aviation lubricant, color decay, antioxidant, inhibition mechanism