The purpose was to clarify the relationship between the main process parameters of micro-plasma cladding and the comprehensive quality(geometry,microstructure and wear rate of cladding track).Self-fluxing ferrous allo...The purpose was to clarify the relationship between the main process parameters of micro-plasma cladding and the comprehensive quality(geometry,microstructure and wear rate of cladding track).Self-fluxing ferrous alloy powders were fabricated on Q235 substrate.Based on the uniform design,the distribution of the experimental samples was designed reasonably in the sample space,which greatly improved efficiency and reduced costs.After a series of microstructural characterization,there was no difference in the phase composition of all samples,but the average grain size had a significant difference,which resulted in the change of wear rate.And the relationship among micro-hardness,average grain size and wear rate of the track had also been investigated.Subsequently,an optimization model was established and the optimal process parameters were obtained with excellent wear rate under the geometric constraints.The correctness of optimization model was verified by experiments.展开更多
A new approach which adopted the idea of coupling bionics to improve erosion resistance was presented, by taking the desert scorpion as the research object. The anti-erosion characteristic rules and mechanism of deser...A new approach which adopted the idea of coupling bionics to improve erosion resistance was presented, by taking the desert scorpion as the research object. The anti-erosion characteristic rules and mechanism of desert scorpion＇s surface under the dynamics effect of gas/solid mixed media were researched, especially the comprehensive influence mechanism of surface morphology, microstructure, creature flexibility and many other factors was studied. Simulation by CFD software was applied to predict the relative erosion severity. Samples with the coupled bionic configurations and flexibility were produced. Experiment optimum design theory was employed to design experiment scheme. Silica sand of particle size of 105-830 ~tm was used as the erodent. The erosion tests were carried out to validate the simulation results obtained. It is shown that the predicted results are in agreement with those obtained from the experiment. And contrast tests were carried out at the best and worst test points of erosion resistance for four samples. Contrast tests show that the erosion resistance trend occurs in such order with the best erosion resistance as coupling sample, groove, smooth and flexibility, and smooth, and the increasing rate of erosion resistances in sequence of 12.08%, 8.87%, 6.03% in the best test point. But in the poorest point, the increasing rate of erosion resistance is in sequence of 15.64%, 9.53%, 6.59%. The morphologies of eroded surface were examined by the scanning electron microscope, and the possible wear mechanism was discussed.展开更多
基金National Key Research and Development Program of China(2016YFB0901600)National Natural Science Foundation of China(51972326,51672295,21871008,51672301)+1 种基金Science and Technology Commission of Shanghai(18YF1427200)The Key Research Program of Chinese Academy of Sciences(QYZDJ-SSW-JSC013)。
基金Project (51210008) supported by National Natural Science Foundation of China
文摘The purpose was to clarify the relationship between the main process parameters of micro-plasma cladding and the comprehensive quality(geometry,microstructure and wear rate of cladding track).Self-fluxing ferrous alloy powders were fabricated on Q235 substrate.Based on the uniform design,the distribution of the experimental samples was designed reasonably in the sample space,which greatly improved efficiency and reduced costs.After a series of microstructural characterization,there was no difference in the phase composition of all samples,but the average grain size had a significant difference,which resulted in the change of wear rate.And the relationship among micro-hardness,average grain size and wear rate of the track had also been investigated.Subsequently,an optimization model was established and the optimal process parameters were obtained with excellent wear rate under the geometric constraints.The correctness of optimization model was verified by experiments.
基金Projects(51205161, 51175220, 51290292) supported by the National Natural Science Foundation of ChinaProjects(20120061120051, 20100061110023) supported by Specialized Research Fund for the Doctoral Program of Higher Education of China+3 种基金Project(OSR-04-04) supported by Cooperation and Innovation to National Potential Oil and Gas for Production and Research, ChinaProject(200905016) supported by Ten Outstanding Youth Fund Project of Jilin University, ChinaProject(2012M511345) supported by China Postdoctoral Science FoundationProject(450060481176) supported by Basic Scientific Research Expenses of Jilin University, China
文摘A new approach which adopted the idea of coupling bionics to improve erosion resistance was presented, by taking the desert scorpion as the research object. The anti-erosion characteristic rules and mechanism of desert scorpion＇s surface under the dynamics effect of gas/solid mixed media were researched, especially the comprehensive influence mechanism of surface morphology, microstructure, creature flexibility and many other factors was studied. Simulation by CFD software was applied to predict the relative erosion severity. Samples with the coupled bionic configurations and flexibility were produced. Experiment optimum design theory was employed to design experiment scheme. Silica sand of particle size of 105-830 ~tm was used as the erodent. The erosion tests were carried out to validate the simulation results obtained. It is shown that the predicted results are in agreement with those obtained from the experiment. And contrast tests were carried out at the best and worst test points of erosion resistance for four samples. Contrast tests show that the erosion resistance trend occurs in such order with the best erosion resistance as coupling sample, groove, smooth and flexibility, and smooth, and the increasing rate of erosion resistances in sequence of 12.08%, 8.87%, 6.03% in the best test point. But in the poorest point, the increasing rate of erosion resistance is in sequence of 15.64%, 9.53%, 6.59%. The morphologies of eroded surface were examined by the scanning electron microscope, and the possible wear mechanism was discussed.
