Fretting Wear Behavior Of Cerium-based Dry Film Lubricant Coating

Fretting corrosion can cause corrosion and wear between the contact surface of the component,and the fatigue crack initiation and propagation of the component is accelerated, which will greatly reduce the fatigue life of component. According to the heat curing test, thermal shock test and thermal weight loss experiment,the thesis studied the heat resistance and adhesion,the modification effect of rare earth cerium (Ce)by adding different amounts of rare earth cerium,which optimized the performance of the existing dry film lubricant.By means of friction and wear test, it can be concluded that the Ce has a certain effect on the dry film lubricant coating, which can improve the anti friction and wear resistance of the coating.Through the analysis of the microstructure of Coating, and constant load constant amplitude under the condition of Fretting wear test, study the effect of the different size and number of rare earth on the wear properties of the coating fretting friction. Further study on the mechanism of Micro Friction and wear mechanism of the optimal adding size and number of rare earth coating by scanning electron microscopy, optical microscopy, X-ray diffractometer.The main work of this thesis and the results achieved are as follows:1、Put forward the MoS2 dry film lubricant coating preparation, and the raw materials which are related are introduced and choiced; get the best coating curing temperature,which is 130℃ for half an hour,and 220℃ for 0.5 hour to 1 hour through curing test; Through thermal shock test and thermo-gravimetric experiment,it is concluded that the ideal amount of rare earth in the coating is less than 8%, and the addition of a certain amount of rare earth cerium can obviously improve the wear resistance of the coating by friction and wear test.2、By comparing and analyzing the microstructure morphology of the lubricating coating with different particle size and number of rare earth cerium, the addition of a certain amount of rare earth cerium can refine the microstructure of the dry film lubricant coating, crystal grains precipitated uniform distribution.Through friction and wear test under the condition of tentering constant load, the optimum formula of dry film lubricant coating was obtained by obtaining the optimum adding amount of rare earth in 1% and particle size 18um.3、On the basis of the optimum coating formulation, further research the new formula of friction and wear characteristics of dry film lubricant coating, test parameter which include the applied load and displacement amplitude and cyclic time and its effects on lubrication coating micro friction properties. Based on the Ft-D curves, the variation curves of friction coefficient and the surface morphology of the wear scar under different load and displacement amplitude, the operating mode of the coating is obtained.By investigating the mechanism of fretting damage coating, get the coating fretting region includes part of slip and slip zone. In the slip zone MoS2 dry film lubricant coating wear mechanism is mainly abrasive wear and oxidation wear.Research shows that:The MoS2 dry film lubrication coating including cerium can improve the corrosion resistance, friction and wear properties of the coating. Through the effect of grinding on the properties of dry film lubricant research of rare earth elements, the paper get the best addition of rare earth element, and proposes an improved dry film lubricant and preparation process, which has important application value. Through the research on the optimal formula of dry film lubricant coating on the wear performance of the system, it is conductive to reveal the fretting wear mechanisms of the coating and has important theoretical significance to research the coating wear mechanism.