Oxidation stability is an indicator of the ability of the oil to resist the oxidizing substance in the external environment

the particulates in oil can easily affect oxidation stability of oil. Based on ISO4406 standard

24 groups of oil samples with different particle sizes

different degree of pollution of copper

iron

and silicon dioxide were made by a uniform design method. Then the thermal oxidation experiment of the 24 groups of oil samples was carried out. The influence of different component and particle content on the oxidation stability of oil was obtained by testing the performance of acid values under the circumstances before and after thermal oxidation experiment of the 24 groups of oil

samples. The mathematical model of partial least squares（PLS） method between particles with different particle size

particle content and oxidation stability of oil samples was established. The results show that the determination coefficient and the root mean square error of the validation set are respectively 0.939 9 and 0.442 1×10

-2

for the mathematical model of the established copper

iron particle and oil oxidation stability. The acid values of the oil containing silicon dioxide after thermal oxidation are less than those of the oil samples containing metal particles. The contamination of metal particles in 15 μm has a significant influence on the oxidation stability of oil

and the change value is 0.066×10

-3

. With the increase of the content of copper and iron particles

the oxidation stability of oil is decreased. The presence of SiO

2

particles in the oil can delay the aging rate of oil and improve the oxidation stability of oil.