Enhancing the heat transfer performance on the oil groove surface of aviation friction plates using dual scale microstructures prepared by WEDM

Abstract

This study proposes a new method for preparing the dual scale microstructures on the surface of oil grooves based on wire electrical discharge machining (WEDM). Firstly, a simulation model for the thermal field and wear during the engagement process of wet friction clutch is established to analyze the temperature field distribution and wear amount. The influence of the speed differences on the engagement characteristics is also explored. Secondly, the method of preparing surface dual scale microstructures based on WEDM is briefly introduced. The surface dual scale microstructure includes discharge morphology (micrometer scale, anisotropic pits and protrusions) and surface texture (submillimeter scale). The optimal process parameters for WEDM are used to achieve the large surface roughness and the high surface texture forming rate. Finally, the experimental research is conducted on the improvement of wet clutch engagement characteristics by surface dual scale microstructures. The results of the confirmatory experimental show that: during the engagement process of wet friction clutch, the relative error between the temperature measurement value and the simulation value on the friction plate is 16.1 %. The prepared surface dual scale microstructure can effectively reduce the maximum temperature on the friction plate, increase the friction torque between friction pairs by 2.03–7.02 %, and decrease the wear amount of the friction plate by 18.28–21.51 %. Therefore, the surface dual scale microstructure proposed in this study can effectively improve the engagement characteristics of the high-performance wet friction clutches, which has good the application value for practical engineering.