Search

Two polymers and five metal pairs were tested at six low temperature points and three constant load speeds. The tribological properties were determined by joint iterative coupling of the temperature, load and friction velocity value. Molecular dynamics simulation was used to study the micro-tribological properties of friction pairs at the atomic scale. The macro-tribological performance test results were similar to the results of the molecular dynamics simulation and exhibited the same trend. Two profound hypothermia points were predicted. The evolution of the tribological mechanism and properties of the polymer interface under different working conditions at low temperature were revealed on the macroscopic and atomic scales. [Display omitted] • A friction mechanism researching method based on a combination of macro and micro research was developed. • The macroscopic and microscopic tribological evolution rules of a polymer interface at low temperature were found. • The simulation was applicable to predicting polymer materials' tribological properties and explaining the test phenomena. • This method can be used for researches under harsher conditions and more extreme environments. [ABSTRACT FROM AUTHOR]

In this paper, the tribological performances of polychlorotrifluoroethylene and polyimide compared with those of 0Cr18Ni9 steel at temperatures as low as − 120 °C were investigated, including varying speed and load. The results demonstrated that the coefficient of friction and wear rate of polychlorotrifluoroethylene were lower and more stable than those of polyimide. The excellent self-cleaning performance of polychlorotrifluoroethylene kept its interface smooth and reduced the coefficient of friction and wear rate. The study demonstrated the superior integrity and sealing performance of polychlorotrifluoroethylene in cryogenic environments, and proved its suitability as a valve component at low temperatures. • The wear rate of PI is not sensitive to decreasing temperature. • The wear rate of PCTFE decreases with decreasing temperature. • The COF of PI increases with decreasing temperature. • PCTFE self-cleaning property ensures a smooth interface and a low COF and wear rate. • PCTFE has better wear and tribological properties than PI at low temperatures. [ABSTRACT FROM AUTHOR]