| Two new kinds of thermoset matrix composite coatings have been developed. Optimal component has been determined by means of orthogonal experimental method, with emphasis on microstructure, corrosion-resistance and tribological properties. By using SEM to examine the worn surface morphology, the wear mechanisms of these coatings were explored. At the same time, the influence of the introduced acrylic and polyamide on the tribological properties of silicone and epoxy, respectively, were also investigated systematically.It is indicated that composite coatings obtain the first-rank properties, when the matrix percentages are in the range of 20wr% to 30wt%. Reinforcement plays an important role in improving the tribological properties of the two coatings. The unique, well-distributed and continuous microstructures offer the best acid-resistance and salt-resistances to the coatings.An air blast tester was also used to study the erosive wear behaviors of SMCC under ambient temperature. The effects of resins ratio, proportion of resin presents, different kinds of ceramic particles, impact angle, velocity of the erodent (alumina, silicon dioxide and calcite) and impact time (expressed by the weight of being used erodent) were demonstrated. The results are listed as following : ㏕he best anti-erosion proportion of resin present is 25wt% in the condition of silicon carbide reinforced SMCC, while the alumina reinforced SMCC is 40wt%. (2) The better anti-erosion results was achieved with the ratio of silicone resin to acrylic resin containing hydroxy being 3: 1. ㏕he composites coating tends to be more brittle when added in alundum particles. It also means that the maximum erosion peak of alundum reinforced SMCC tends to normal angle. 甌he change of erosion rate of SMCC can be divided into two stages with the increment erodent velocity: the slow erosion stage of the beginning and the stable erosion stage. 'EM analysis the worn surface morphology shows the following results: elastic deformation and fatigue are the main wear mechanisms of SMCC when impacted with lower erodent velocity, while the dominant mechanisms change into microcutting and microploughing with the increment erodent velocity.The slurry erosion behaviors of ceramic particles reinforced epoxy matrix composite coating were explored using a self-designed slurry pot tester. The optimal erosion resistance was reached through varying the type of reinforcing particles and their percentage in the coating. For Sic reinforced coating the optimal reinforcing particle content ranges from 60 wt.% to 70 wt.%, while for a-Al2O3 reinforced coating the content ranges from 55% to 65%. The ratio of curing agent to epoxy resin has very important influence on the slum' erosion resistance of composite coating. It was also found that the protecting effect of erodents on the coating surface does exist. The protecting effect will be more evident if using erosion efficiency of unit mass erodent of sand in the slurry to describe the erosivity of erodent. Besides a model is proposed to explain the protection process. The wear mechanism of the coating is the co-operation of ploughing, cracking and ablation. Besides of that, the native pinholes in the subsurface are also made some contribution to the inner-stress and ablation of the composite coatings.The dry sliding wear behavior of SMCC was tested on an modified MM200 rig. The effects of sliding speed and load on the frictional coefficient and wear rate were determined. There also exist three distinct stage, i.e. running -in, steady-state and severe wear stage, with increasing sliding distance. SEM was employed to examine the worn surface. The SEM images show that the SMCC exhibits mild wear under low load, which transfers to severe one once the applied load exceeds a critical value. The mechanisms of mild wear contain adhension and elastic deformation at low applied, with increasing applied load, the strain accumulated adhension and severe adhensive wear occurs. Plastic deformation accumulate under the surface, the micr... |
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