为改善440C不锈钢航空精密液压滑阀零件的加工质量和效率,开展了基于响应曲面法(response surface methodology,RSM)和多目标灰狼优化算法(multi-objective grey wolf optimizer,MOGWO)的磨削工艺参数优化研究。利用响应曲面法分别建立...为改善440C不锈钢航空精密液压滑阀零件的加工质量和效率,开展了基于响应曲面法(response surface methodology,RSM)和多目标灰狼优化算法(multi-objective grey wolf optimizer,MOGWO)的磨削工艺参数优化研究。利用响应曲面法分别建立了表面粗糙度和圆柱度的回归模型;通过方差分析和响应曲面图分析,明确了磨削参数对试件表面粗糙度和圆柱度的交互影响;综合考虑加工质量和效率,采用MOGWO算法获得了多目标磨削工艺参数优化的Pareto解集,并结合层次分析法(analytic hierarchy process,AHP)和优劣解距离法(technique for order preference by similarity to ideal solution,TOPSIS)得到了决策解。结果表明,在保证加工质量的前提下,材料去除率提升约20%,具有较高的工程应用价值。展开更多
Carbon atoms segregate in the surface region for polished AISI 440C stainless steel After ion implanta tion, the surface carbon atoms exist in different forms. To elucidate their existence, surface structures and carb...Carbon atoms segregate in the surface region for polished AISI 440C stainless steel After ion implanta tion, the surface carbon atoms exist in different forms. To elucidate their existence, surface structures and carbon chemical states o[ unimplanted, N~ implanted, Ti＋ implanted and N＋/Ti＋ co-implanted samples were analyzed by X-ray diffraction （XRD）, transmission electron microscopy （TEM） and X-ray photoelectron spectroscopy （XPS）. The results indicated that various phases form in the surface or subsurface region after ion implantation, while the surface topography of the samples remains intact. For polished unimplanted sample, besides some Fe3 C phase and C- C phase, Cr, Cs phase dominates its surface region. Little change of carbon chemical states occurs after N＋ ion im- plantation. For Ti＋ implanted sample, besides some metal oxycarbide phases, most carbon amorphous phases form in surface region. Concerning N＋/Ti＋ co-implantation, CrrCs compound as well as Fe^C phase dominates the sur face region while no C-C phase is found. In addition, compared with single ion implantation, N＋/Ti＋ co-implanta tion would increase the ion implantation depth significantly. The formed phases of the carbon atoms play an impor- tant role in affecting the surface properties of AISI 440C stainless steel.展开更多
文摘为改善440C不锈钢航空精密液压滑阀零件的加工质量和效率,开展了基于响应曲面法(response surface methodology,RSM)和多目标灰狼优化算法(multi-objective grey wolf optimizer,MOGWO)的磨削工艺参数优化研究。利用响应曲面法分别建立了表面粗糙度和圆柱度的回归模型;通过方差分析和响应曲面图分析,明确了磨削参数对试件表面粗糙度和圆柱度的交互影响;综合考虑加工质量和效率,采用MOGWO算法获得了多目标磨削工艺参数优化的Pareto解集,并结合层次分析法(analytic hierarchy process,AHP)和优劣解距离法(technique for order preference by similarity to ideal solution,TOPSIS)得到了决策解。结果表明,在保证加工质量的前提下,材料去除率提升约20%,具有较高的工程应用价值。
基金Sponsored by National Natural Science Foundation of China(51075004)Funding Project for Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijing Municipality(PHR201107109)Importation and Development of High-caliber Talents Project of Beijing Municipal Institutions(CIT&TCD201304005)
文摘Carbon atoms segregate in the surface region for polished AISI 440C stainless steel After ion implanta tion, the surface carbon atoms exist in different forms. To elucidate their existence, surface structures and carbon chemical states o[ unimplanted, N~ implanted, Ti＋ implanted and N＋/Ti＋ co-implanted samples were analyzed by X-ray diffraction （XRD）, transmission electron microscopy （TEM） and X-ray photoelectron spectroscopy （XPS）. The results indicated that various phases form in the surface or subsurface region after ion implantation, while the surface topography of the samples remains intact. For polished unimplanted sample, besides some Fe3 C phase and C- C phase, Cr, Cs phase dominates its surface region. Little change of carbon chemical states occurs after N＋ ion im- plantation. For Ti＋ implanted sample, besides some metal oxycarbide phases, most carbon amorphous phases form in surface region. Concerning N＋/Ti＋ co-implantation, CrrCs compound as well as Fe^C phase dominates the sur face region while no C-C phase is found. In addition, compared with single ion implantation, N＋/Ti＋ co-implanta tion would increase the ion implantation depth significantly. The formed phases of the carbon atoms play an impor- tant role in affecting the surface properties of AISI 440C stainless steel.
