| Heavy-duty friction pairs are one of the key components of the molding equipment, the tribological properties of friction pairs are important for equipment performance, the metal-based backing polymer composite material is a new kind of high-performance friction pair materials, has become one of the development trends owing to the superior mechanical properties, non-polluting. simple molding process, low production costs and so on.Based on the friction pairs preparation of steel backing/carbon fiber fabric reinforced-polymer lining friction composite materials, the goal of this thesis is to optimize the interfaces of metal/polymer and carbon fiber/polymer, by studying the surface pretreatment methods of mental and carbon fiber (CF), discussing the influence and mechanism on the two interfacial mechanical properties by micro analysis and mechanical tests, and getting the optimal interface treating methods meeting the technical requirements of heavy-load friction pairs. The main research contents are as follows:Firstly of all, the technology and methods of mechanical and chemical pretreatments(such as mechanical scratches, grinding with emery paper, blasting, acid etching, phosphating and sliane coupling agents)were studied, the shearing test were aim to ravel in order to study various treatments, the surface morphology were analyzed by means of profilometer. super depth three-dimensional microscope and scanning electron microscope (SEM), the mechanism of influence on interface bongding strength was studied. The results show that metal surfaces are coarsening after mechanical scratching, grinding with emery paper and blasting. The processing grooves are so large that it is easy to produce "dissatisfaction" phenomenon after mechanical scratching, comparing with grinding by emery paper, blasting can increase the anisotropy of surface; metal surfaces are cleaner and forming micropore structures after acid etching, it is advantageous to the formation of chemical bondings; Metal surfaces can form micro voids and cracking structures after phosphating, they can increase the bonding areas; Coupling metal pretreatment helps metal surface forming "molecular bonding bridge", makes the metal/polymer interfaces mainly connect by chemical bondings, the bonding strength is up to23.11MPa.Second, the technology and methods of carbon fiber pretreatments(such as air phase oxidation, liquid-phase oxidation, silane coupling agents, double treatrs)were studied, interfacial shear strength(IFSS) were aim to ravel in order to study various treatments. The changes in morphology, surface roughness, surface element composition, surface chemical structure, mechanical properties after surface treatment of CFs were characterized by scanning electronic microscopy(SEM), atomic force microscopy(AFM), element analysis(EA), fourier transform infrared test(FTIT). mechanical property tests. The results show that original CFs are smooth, lacking active elements, the interface bonding of composite materials is poor; Air oxidation treatment is given priority to etching effect, increase the carbon fiber surface roughness, but activity elment on the surface has a little change; the optimal treatment of Liquid-phase oxidation is nitric acid95℃/90min, mechanical anchoring contract with chemical bonds on the interface of the composite material, it can be confirmed that both mechanical interaction and chemical bonding interaction have effects on interfacial adhesion of composites, mechanical interaction plays a leading role; after treating by coupling agent KH560which concentration is3%,the IFSS is43.2MPa the bending strength is1088.9MPa、the tensile strength is538.1MPa、the impact strength is72.2KJ·VP and the comprcssive strength is551.3MPa. coupling agents have pairs of molecules so that they can react with the carbon fiber surface and the polymer into chemical bonds; double processing can effectively make up for the carbon fibre damages cousing by gas phase oxidation and liquid phase oxidation, but the comprehensive mechanics analysis of test results show the optimal carbon fiber fabric interface treatment method is solubility of3%coupling agent KI1560processing. |
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