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111.
Influence of molybdenum on passivation of polarised stainless steels in a chloride environment 总被引:2,自引:0,他引:2
Polarised specimens of AISI 304L and 316L stainless steels (SS) were studied using X-ray photoelectron spectroscopy in conjunction with Ar+-ion sputtering. A 5% NaCl test solution was used at room temperature. The polarised passive films formed consist mainly of chromium oxide and hydroxide and a small proportion of iron oxides. The composition of the films depend strongly on the potential. Chloride and molybdenum ions appear when the AISI 316L SS alloy is polarised at a potential close to pitting potential. 相似文献
112.
The response of sputter deposited Fe-15Cr and Fe-25Cr alloys to a rapid potential increase in the passive region was studied using two in situ methods: electrochemical quartz crystal microbalance and inductive coupled plasma-atomic emission spectroscopy (ICP-AES). Both methods indicated an increase in the dissolution rate of iron following the potential change; the total amount of material dissolved being higher for the Fe-15Cr alloy. For both alloys, about 10% of the total dissolved material was Cr. This result compared well with experiments on a 430 stainless steel. ICP-AES is shown to be useful for the in situ determination of partial currents of metal dissolution using solution analysis in a flow cell. 相似文献
113.
114.
HUANG Jianshun CHEN Junming Shanghai Institute of Metallurgy Academia Sinica Shanghai China Research Associate Shanghai Institute of Metallurgy Academia Sinica Shanghai China 《金属学报(英文版)》1993,6(7):69-75
Crystal structure of γ-Li_xFe_2O_3,inserted Li electrochemically,was studied by Moss-bauer spectroscopy together with X-ray diffraction,XPS and electrochemical method,Onthe insertion of Li at low current density,the crystal structure is keeping original spinel;while at higher current density or by thermal activation,owing to violent movement ofLi~+ ions,part of crystal structure transforms into rock type similar to face-centeredcubic structure of ferrous oxide.The transition channels during insertion of Li~+ ions andlimitation of Li~+ ions inserted were discussed. 相似文献
115.
Y. H. Cheng X. L. Qiao J. G. Chen Y. P. Wu C. S. Xie Y. Q. Wang D. S. Xu S. B. Mo Y. B. Sun 《Surface & coatings technology》2002,160(2-3)
Carbon nitride films were deposited by direct current plasma assisted pulsed laser ablation of a graphite target under a nitrogen atmosphere at room temperature. The surface morphology, composition and bonding structure of the deposited films were characterized by atomic force microscopy (AFM), Fourier transform infrared (FTIR) spectroscopy, Raman, and X-ray photoelectron spectroscopy (XPS). The effect of laser fluences in the range 0.5–3 J/cm2 on the surface morphology, composition and bonding structure of the carbon nitride films were systematically studied. As laser fluence is increased, AFM results show a great decrease in the surface roughness of carbon nitride films. FTIR and XPS results indicate an increase in the N/C ratio and the content of N atoms bonded to sp3 C, as well as a decrease in the content of H atoms and the content of N atoms boned to sp2 C in the deposited films, and Raman spectra indicate an increase in the content of disordered sp2 C atoms and the sp2 cluster size. The increase in the film density and the decrease in the particle fraction contribute to the decrease of surface roughness with increasing laser fluence. 相似文献
116.
论述了在直齿轮分度圆直径为定值时,变形程度与模数的关系。通过对三种不同模数的齿轮在特定的条件下温挤压成形数值模拟,结果及分析表明,随着齿轮模数的增大,变形程度也增大,金属向齿顶及周围流动就相对较多,齿形就容易充满,但齿轮头部内凹与头的齿部凸肚现象就越厉害。 相似文献
117.
LaF3 superfine powder was synthesized from La(CH3COO)3 and NH4 F by microwave heating method,using ethanol or pure water as dispersants respectively. The results of XRD and SEM indicate that the superfine powder has high purity, regular particle shape and narrow distribution of granularity. The granularity of the best sample is in the range of 100 -200 nm. The influence of different dispersants on the crystal degree and microstructure was discussed. After the superfine powder was formed into a slice at pressure of 25 - 60 MPa, its electrochemical impedance spectroscopy was tested by electrochemical impedance spectroscopy (EIS) measurement. The result shows that the grain refining of LaF3 powder increases its ionic conductivity. Compared with traditional preparation methods of LaF3 powder, the advantages of microwave heating method were summarized. 相似文献
118.
The molecular orientation at the outer surface of injection–stretch–blow‐molded bottles made from poly(ethylene terephthalate) was characterized and quantified by means of front‐surface reflection infrared spectroscopy based on a method developed previously. Results were obtained for two different bottle shapes (cylindrical and rectangular) molded at different injection mold temperatures (16, 38, and 60°C). For the cylindrical bottles, the preferred molecular chain orientation was found to be in the axial direction, with the Hermans orientation function near 0.3 for all three mold temperatures. For the less symmetrical rectangular bottles, a significant difference was observed between the large and small faces. For the large face, the orientation was mainly in the hoop direction; the Hermans orientation function was in the range of 0.3–0.5 and was essentially the same at all mold temperatures and positions along the bottle height. For the small face, on the other hand, the preferred orientation changed from the hoop direction near the bottom to the axial direction near the top, and the variation was more pronounced at lower mold temperatures. The utility of the front‐surface reflection technique was clearly demonstrated. It was also applied, with the use of an infrared microscope, to examine the orientation gradient across the wall thickness. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1319–1327, 2007 相似文献
119.
Ji-Er Huang 《Carbon》2003,41(14):2731-2736
Single-walled carbon nanotube (SWNT)/polyaniline (PANI) composite films with good uniformity and dispersion were prepared by electrochemical polymerization of aniline containing well-dissolved SWNTs. The results of atomic force microscopy (AFM) and UV-Vis adsorption spectroscopy show that aniline can be used to solubilize SWNTs via formation of donor-acceptor complexes. The electrochemical deposition of SWNT-aniline solutions have been investigated by cyclic voltammetry. The results show that SWNT-based aniline solutions exhibit a drastic increase in peak current within the potential scanning region. The doping effect of SWNTs on PANI films was investigated by electrochemistry and FTIR spectroscopy. The results indicate that the enhanced electroactivity and conductivity of the SWNT/PANI composite films may be due to the strong interaction between SWNTs and PANI, which facilitates the effective degree of electron delocalization. 相似文献
120.
A. Domingue K. Piyakis E. Sacher M. Di Renzo S. D nomm e T. H. Ellis 《The Journal of Adhesion》1993,40(2):151-162
The irreversibly bound interfacial layer deposited by the γ-aminopropysilanetriol adhesion promoter onto a crystalline silicon substrate, which remains even after profuse washing, was found by XPS to have resulted from the fragmentation and rearrangement of the original γ-aminopropylsilanetriol molecule. A mechanism is proposed, involving the homolytic scission of the terminal N-C bond. One of the subsequent reactions is believed to involve hydrogen loss by abstraction and the formation of a terminal vinyl group, which bonds to the substrate. Support for this mechanism is found in IR spectroscopy of this layer. 相似文献