| The friction and wear in the mechanical system will cause the wear of the equipment,the decline of the machine performance and the early failure of the component,which will lead to catastrophic accidents and cause substantial economic losses.Therefore,it is of great importance to reduce friction and wear in the mechanical system.Polymer coatings are widely used in various protective wear-resistant coatings because of their lightweight and easy processing,and the lubrication and wear resistance of epoxy coatings modified by nanoparticles are improved.However,to improve the durability of epoxy wear-resistant coatings,it is also necessary to develop experimental methods and techniques for evaluating the interfacial strength of coatings.In this paper,the mechanical properties of epoxy coatings modified by nanoparticles are studied.The main contents and conclusions are as follows:1.The CNF/MoS2 modified epoxy coating composite of MoS2 and CNF was prepared and characterized,revealing the mechanical mechanism of good lubricity and low wear rate of CNF/MoS2 modified epoxy coating.The results show that the MoS2 sheet will form a coiled structure when it grows on the CNF surface,which increases the specific surface area of CNF/MoS2 hybrid particles.MoS2 improves the lubricity of the coating,while the high hardness CNF reduces the wear rate of the coating.The elastic modulus,hardness,creep properties and friction properties of the coating modified by CNF/MoS2 hybrid particles are greatly improved than those of the single-particle modified coating.2.The coating interface strength assessment method based on the deformation field of the crack tip is developed.Through the finite element method,the simulation verifies the correctness of the method and the feasibility of experimental testing.The results show that the stress intensity factor calculated based on the interfacial crack tip opening displacement is in good agreement with the theoretical solution.The results of the simulated Brazilian disk interface loading test show that the required accuracy of the interface displacement measurement meets the requirements of the subsequent micro-scale optical deformation test.3.The interface fracture loading device of mixed-mode under micro-scale is designed,and the experimental testing device of coating interface strength based on micro-optical deformation measurement is established to realize the interfacial strength evaluation of polymer wear-resistant coating.The experimental results show that the established test device can realize the 2mm field of view range of coating interface deformation test.Moreover,the distribution of crack tip opening displacement of the coating interface in accordance with the theoretical prediction.Through the multi-angle disguised position angle loading,I and II fracture strength factors are obtained,as well as safe areas.Besides,the interfacial fracture toughness of CNF/MoS2 hybrid particle epoxy coating is about 30% higher than that of MoS2 particle coating. |
PDF Full Text Request