Friction and wear phenomenon is a complex nonlinear system,and it is also a significant problem in the process of metal cutting.In order to systematically analyze the friction and wear process of tool material-workpie...Friction and wear phenomenon is a complex nonlinear system,and it is also a significant problem in the process of metal cutting.In order to systematically analyze the friction and wear process of tool material-workpiece material friction pair in the cutting process of high hardness alloy steel under different lubrication conditions,the chaotic characteristics of friction process between high hardness alloy steel and cemented carbide under the lubrication C60 nano-particles fluid are studied based on the chaos theory.Firstly,the friction and wear experiments of the friction pair between high hardness alloy steel and cemented carbide tool are carried out based on the ring-block friction and wear tester,and the results of friction force signal in time domain and wear width are obtained.Then,the friction signals in time domain are processed and transformed based on phase space reconstruction and recurrence plot theory,and the recurrence plots of different experimental groups under different lubrication conditions are generated.The evolution law of recurrence plot is further observed and studied,and the recursive quantitative index is analyzed.Finally,the cutting experiments of tool wear are carried out.The results show that the proposed method can intuitively and accurately reveal the wear evolution process and the wear feature identification law of the tool material-high hardness alloy steel pair under different lubrication conditions.Meanwhile,it is found that when the concentration of C60 nanoparticles is 200∼300 ppm,the stability of the friction pair system is best.The proposed method can provide a strategy for wear prediction in cutting process,and provide a theoretical basis and technical support for antifriction lubrication methods in practical cutting applications.展开更多
Measurements of Surface Photovoltage Spectroscopy(SPS)Were carried out for C60(A)and its anion salt(B)for the first time.With a reference of UV-vis spectra,the results for SPS are discussed in terms of Molecular Orbit...Measurements of Surface Photovoltage Spectroscopy(SPS)Were carried out for C60(A)and its anion salt(B)for the first time.With a reference of UV-vis spectra,the results for SPS are discussed in terms of Molecular Orbit(MO) and Surface Photovoltage(SPV)theory. By a comperison between(A)and(B)'s characteristic responses is SPS,a deeper insisht into the nature of their photovoltaic properties is obtained.展开更多
The fullerene complex, η 2 C 60 [Ru(NO)(PPh 3)] 2, has been prepared by the reaction of C 60 with Ru(NO) 2(PPh 3) 2 under a nitrogen atmosphere and refluxing. The new complex was characterized by means of elemental a...The fullerene complex, η 2 C 60 [Ru(NO)(PPh 3)] 2, has been prepared by the reaction of C 60 with Ru(NO) 2(PPh 3) 2 under a nitrogen atmosphere and refluxing. The new complex was characterized by means of elemental analysis, IR, XPS, electronic spectra and 31 P NMR. The results show that the complex of η 2 form can be formed by C 60 bonding to Ru(NO) 2(PPh 3) 2 in the σ π way and there is hyperconjugation effect in the molecule. So electrons will flow easier and photoelectric effect for this new compound is expected. In addition, the structure of the complex has been supposed. The ruthenium is 4 coordinate in the complex, bonding to two carbon atoms, to one PPh 3 and to one NO.展开更多
基金The work is financially supported by National Natural Science Foundation of China(No.51605403)National Key Research and Development Project(2020YFB1713503)+3 种基金Natural Science Foundation of Guangdong Province,China(No.2015A030310010)Natural Science Foundation of Fujian Province,China(No.2016J01012)the Aero-nautical Science Foundation of China(No.20183368004)the Fundamental Research Funds for the Central Universities under Grant(No.20720190009).
文摘Friction and wear phenomenon is a complex nonlinear system,and it is also a significant problem in the process of metal cutting.In order to systematically analyze the friction and wear process of tool material-workpiece material friction pair in the cutting process of high hardness alloy steel under different lubrication conditions,the chaotic characteristics of friction process between high hardness alloy steel and cemented carbide under the lubrication C60 nano-particles fluid are studied based on the chaos theory.Firstly,the friction and wear experiments of the friction pair between high hardness alloy steel and cemented carbide tool are carried out based on the ring-block friction and wear tester,and the results of friction force signal in time domain and wear width are obtained.Then,the friction signals in time domain are processed and transformed based on phase space reconstruction and recurrence plot theory,and the recurrence plots of different experimental groups under different lubrication conditions are generated.The evolution law of recurrence plot is further observed and studied,and the recursive quantitative index is analyzed.Finally,the cutting experiments of tool wear are carried out.The results show that the proposed method can intuitively and accurately reveal the wear evolution process and the wear feature identification law of the tool material-high hardness alloy steel pair under different lubrication conditions.Meanwhile,it is found that when the concentration of C60 nanoparticles is 200∼300 ppm,the stability of the friction pair system is best.The proposed method can provide a strategy for wear prediction in cutting process,and provide a theoretical basis and technical support for antifriction lubrication methods in practical cutting applications.
文摘Measurements of Surface Photovoltage Spectroscopy(SPS)Were carried out for C60(A)and its anion salt(B)for the first time.With a reference of UV-vis spectra,the results for SPS are discussed in terms of Molecular Orbit(MO) and Surface Photovoltage(SPV)theory. By a comperison between(A)and(B)'s characteristic responses is SPS,a deeper insisht into the nature of their photovoltaic properties is obtained.
文摘The fullerene complex, η 2 C 60 [Ru(NO)(PPh 3)] 2, has been prepared by the reaction of C 60 with Ru(NO) 2(PPh 3) 2 under a nitrogen atmosphere and refluxing. The new complex was characterized by means of elemental analysis, IR, XPS, electronic spectra and 31 P NMR. The results show that the complex of η 2 form can be formed by C 60 bonding to Ru(NO) 2(PPh 3) 2 in the σ π way and there is hyperconjugation effect in the molecule. So electrons will flow easier and photoelectric effect for this new compound is expected. In addition, the structure of the complex has been supposed. The ruthenium is 4 coordinate in the complex, bonding to two carbon atoms, to one PPh 3 and to one NO.
