Surface & Coatings Technology
Well-adhered gamma-Al2O3 coating layers can be formed on FeCrAl metallic supports for the preparation of structured catalysts in diesel particulate filter (DPF) systems using a three-step method-pre-oxidation, primer deposition and coating deposition. The optimal pre-oxidation is at 950 degreesC for 10 h; the optimal primer sol calcination is at 800 degreesC for 3 h; and the optimal gamma-Al2O3 slurry calcination is at 900 degreesC for 2 h. If the oxidation temperature is 1050 degreesC, only 0.5 h is required to obtain almost the same coating adhesion level as at 950 degreesC for 10 h. The data concerning effects of the major preparation parameters (the pre-oxidation time, temperature, primer calcination temperature and the coating calcination temperature) are presented herein. The coating adhesion was measured by ultrasonic adhesion, thermal shock and interface shear strength tests. (C) 2002 Elsevier Science B.V. All rights reserved.
关键词:
gamma-Al2O3 washcoat;metallic support;adhesion;oxidation;thickness;stress
材料科学技术（英文）
The fractal growth and form is considered by molecular dynamics and simulated using computer.
关键词:
LIU Hefa SUN Naizhen DAI Xueli REN He Zhenjiang Shipbuilding Institute
,
Zhenjiang
,
Jiangsu
,
ChinaLI Lijun Shanghai
,
Electrical Machinery Plant.Shanghai.China professor.Institute of Metallic Materials Research
,
Zhenjiang Shipbuilding Institute
,
Zhenjiang
,
Jiangsu 212003
,
China
金属学报(英文版)
Precipitation form of Zr in CuCoBeZr alloy during solidificotion.cooling and final aging,as well as its effect on the high temperature properties have been studied and discussed.Results show that during solidificotion and cooding.Zr precipitates as fine particle.Cu_3Zr,which pre- vents X-Cu grains from growing and provides more nuclei for CoBe and hence leads to finer primary CoBe.Fine Cu_3Zr partrticles also precipitate during aging. Because Co_3Zr is difficult to coalesce at high temperatures,the recrystallization temper- uture increases and the high temperature mechanical properties improve.
关键词:
CuCoBeZr alloy
,
null
Jun SHEN
,
Jianguo LI
,
Hengzhi FU
,
Junyi SU
材料科学技术（英文）
The relationship between melt shape, electromagnetic pressure and magnetic field is studied for electromagnetic confinement and shaping of plate-form part. The results of experimental observation and theoretical inference can be summarized as follows. As the melt thickness a is large enough, causing the ratio of plate thickness to current theoretic skin depth a/delta larger than 2.2, the electromagnetic pressure acting on melt can be simply expressed as P-m = B-2/2 mu, and the melt shape would be known only by measuring the distribution of magnetic flux density As a is small and makes the ratio a/delta less than 2.2, the melt shape and electromagnetic pressure for confining and shaping are determined not only by magnetic flux density B but also by melt thickness a, electromagnetic parameter mu gamma and current frequency f. In this paper, an equation used to calculate electromagnetic pressure acting on "thin plate-form melt" is brought forward. The equation gives a precise relationship between electromagnetic pressure factor p and melt thickness a, electromagnetic parameter mu gamma and current frequency f.
关键词:
Acta Physico-Chimica Sinica
The relationship bettween the existing form and inhibiting behavior of dolecylamine(DDA) on amorphous alloy has been studied by electrochemical measurement, physical test and scanning tunneling microscopy. The experiment shows that there is different relationship between the inhibition concentration and inhibition percentage in different concentration scale. In w(DDA)=10(-6) similar to 10(-4) concentration range, the inhibition percentage increased strongly with the inhibitor concentration but the increase tendency of inhibition percentage became gently in 10(-4) similar to 10(-3) concentration scale. The adsorption isotherm formula fitting result shows that a typical mono-molecular layer of DDA was adsorbed on amorphous alloy during 10(-6) similar to 10(-4) concentration scale, without any effect from the neighbor inhibitor molecule, but in 10(-4) similar to 10(-3) range the force between the nearing neighbor inhibitor molecule decided the adsorption form. The result from STM and conductivity test indicats that the micelle had been formed when the concentration approached w(DDA)=2.3x10(-5), the protection effect DDA was prevented because of the forming of micelle.
关键词:
dodecylamine;micelle;inhibiting mechanism
Masaharu Yamaguchi and Haruyuki Inui(Department of Metal Science and Technology
,
Kyoto University
,
Sakyo-ku
,
Kyoto 606
,
Japan)
材料科学技术（英文）
In two-phase TiAl alloys, the lamellar structures are of special interest and importance since they are so common and persistent. not only under as-cast conditions but also after thermal treatment. However. the lamellar structures are still poor in ductility,although they are beneficial for toughness and high temperature strength. This article will review the recent progress made in understanding the basic mechanical properties of the γ and α2 phases which comprise the two-phase alloys in Iamellar form, and discuss how an improved balance of strength and ductillty in the lamellar form may be achieved
关键词:
Pai-Shan Pa
材料科学技术（英文）
A reuse fabrication module using micro electroetching as a precision machining process with a new design of a slant-form tool to remove the defective indium-tin-oxide (ITO) nanostructure from the optical poly-ethyleneterephthalate (PET) surfaces of digital paper display is presented in current studies. The low yield of ITO thin film deposition is an important factor in optoelectronic semiconductor production. The adopted precision reuse process requires only a short period of time to remove the ITO nanostructure easily and cleanly, which is based on technical and economical considerations and is highly efficient. In the current experiment, a large inclined angle of the cathode and a small end radius of the anode take less time for the same amount of ITO removal. A higher feed rate of the optical PET diaphragm combines with enough electric power to drive fast micro electroetching. A small rotational diameter of the anode accompanied by a small width of the cathode corresponds to a higher removal rate for the ITO nanostructure. A pulsed direct current can improve the effect of dreg discharge and is advantageous to couple this current with the fast feed rate of the workpiece. This improvement is associated with an increase in current rating. High rotational speed of the slant-form tool can improve the effect of dregs discharge and is advantageous to associate with the fast feed rate of the workpiece (optical PET diaphragm).
关键词:
Reuse fabrication
Pai-Shan Pa
材料科学技术（英文）
A reuse fabrication module using micro electroetching as a precision machining process with a new design of a slant-form tool to remove the defective indium-tin-oxide (ITO) nanostructure from the optical poly-ethyleneterephthalate (PET) surfaces of digital paper display is presented in current studies. The low yield of ITO thin film deposition is an important factor in optoelectronic semiconductor production. The adopted precision reuse process requires only a short period of time to remove the ITO nanostructure easily and cleanly, which is based on technical and economical considerations and is highly efficient. In the current experiment, a large inclined angle of the cathode and a small end radius of the anode take less time for the same amount of ITO removal. A higher feed rate of the optical PET diaphragm combines with enough electric power to drive fast micro electroetching. A small rotational diameter of the anode accompanied by a small width of the cathode corresponds to a higher removal rate for the ITO nanostructure. A pulsed direct current can improve the effect of dreg discharge and is advantageous to couple this current with the fast feed rate of the workpiece. This improvement is associated with an increase in current rating. High rotational speed of the slant-form tool can improve the effect of dregs discharge and is advantageous to associate with the fast feed rate of the workpiece (optical PET diaphragm).
关键词:
Reuse fabrication
Intermetallics
The oxidation of Cu-6.8Al (at.%) alloy has been studied at 800 and 900 degrees C in 1 x 10(5) Pa pure O-2. The scales formed at 800 degrees C are composed of a thin outer CuO layer and an inner protective Al2O3 layer. On the contrary, at 900 degrees C different samples of the alloy present two kinds of different oxidation behavior: one is protective, very similar to that at 800 degrees C. while the other is intermediate between protective and non-protective, with formation of very thick scale on the partial surface, which is mainly composed of copper oxides. The different behavior presented on a single sample is probably caused by local inhomogeneities of the alloy. It is deduced that at 900 degrees C the critical Al content to form external-alumina scale on Cu-Al alloy is about 6.8 at.%. (C) 2006 Elsevier Ltd. All rights reserved.
关键词:
dispersion strenthening;oxidation;microstructure;corrosion behavior;environniental applications;pure o-2;copper-alloys;oxidation;components;1-atm
