C.G.Shi
,
Y.H.Wang
,
L.G.Cai
,
C.H.Zhou
金属学报(英文版)
There are four new achievements of this work on the theory and technology of explosive welding.(1) It has been found and defined three kinds of bonding interfaces: big wavy, small wavy and micro wavy, and the micro wavy interface is the best. In a cladding plate,it is for the first time to find that the form of interface presents regular distribution.(2) Although the interface has the features of melt, diffusion and pressure welding in the mean time, the seam and "hole" brought by the melt weaken the bonding strength of interface greatly, and the effect of melt on interface must be eliminated in explosive welding, so explosive welding is not a melt weld. The diffusion welding is a kind of form of pressure welding, and the diffusion is not the reason of the bonding of interface but the result of interface high pressure. So the diffusion welding cannot also explain the bonding mechanism of it. The experiment and theory make clear that explosive welding is a special pressure one.(3) To get good interface of no melt, explosive charge must be selected on the low limit of welding windows. In explosive welding, the drive plate should be treated as the viscous and plastoelastic body, not incompressible fluid. The bending moment under the explosive welding loading must be greater than that under dynamic limit of drive plate. According to the condition, the lower limit of explosive welding is obtained. It is about 20 1.019373e-312ss than that obtained by tradition calculation, and suitable for engineering application.(3) It is for the first time to test and study on soil anvil characteristics and change regularity under explosive welding impact loading. Through soil anvil parameter optimization analysis, it is the best for explosive welding with sandy soil of water content 17.00and density 1.74g/cm^3.
关键词:
explosive welding
,
null
,
null
Zhihua LIU
,
Qing ZHAO
,
Deqing LI
材料科学技术（英文）
In this paper, technology margin experiment of hollow cathode fusion are welding (FAW) and penetrating are welding (PAW) is presented in detail. The advantages of PAW, compared with FAW, are better weld formation, narrower welds, as well as a larger welding technology margin. Technological experiment and hydraulic test for the Ti alloy pressure vessels with PAW are described. Also, the weld formation control on Ti alloys is preliminarily analyzed. Finally, conclusions are addressed.
关键词:
Irina N.Mutilina
材料科学技术（英文）
The application of mechanical and chemical syntheses in an high-energy vibration mill of the FESTU makes easy the process of the introduction of reinforced powders in castle composite materials on the Al basis. The obtained reinforced phases of Al-Ti-C composition have high specific Surface due to peculiarities of explosive mechanical and chemical syntheses. It increases the uniformity of their distribution in a matrix melt during the mixing process and also increases properties of castle composite materials
关键词:
Oxidation of Metals
The oxidation of Fe- Y alloys containing 2 and 5 at.% Y and pure iron has been studied at 600-800 degrees C in air. The oxidation of pure iron follows the parabolic rate law at all temperatures. The oxidation of Fe-Y alloys at 600 degrees C approximately follows the parabolic rate law, but not at 700 and 800 degrees C, where the oxidation goes through several stages with quite different rates. The oxide scales on Fe-2Y and Fe-5 Y at 700 and 800 degrees C are composed of external pure Fe oxides containing Fe2O3, Fe3O4, and FeO, with FeO being the main oxide and an inner mixture of FeO and YFeO3. The scales on Fe-2Y and Fe-5Y at 600 degrees C consist of Fe2O3, Fe3O4, and Y2O3, with a minor amount of FeO. Significant internal oxidation in both Fe-Y alloys occurred at all temperatures. The Y-containing oxides follow the distribution of the original intermetallic compound phase in the alloys. The effects of Y on the oxidation of pure Fe are discussed.
关键词:
pure Fe;Fe-Y alloys;oxidation;high-temperature oxidation;possible scaling modes;2-phase;binary-alloys;low-oxygen pressures;oxidant pressures
Corrosion Science
The oxidation of pure Co and two Co-Y alloys containing 2 at.% and 5 at.% Y has been studied at 600-800 degrees C in air. The oxidation of pure cobalt at all temperatures followed the parabolic rate law. The oxidation of the two alloys approximately followed the parabolic rate law at 800 degrees C, but was closer to cubic behavior at 600 and 700 degrees C except Co-5Y at 600 degrees C, which deviated from the cubic and parabolic rate law. The corrosion of both alloys at the three temperatures produced an external scale containing Co oxides (Co3O4, CoO) and Y2O3 and an internal oxidation region where Co17Y2 was converted into Co and Y2O3. The distribution of Y2O3 closely followed that of the intermetallic compound (Co17Y2) in the original alloy. The corrosion mechanism of the alloys is examined. (C) 1999 Elsevier Science Ltd. All rights reserved.
关键词:
Co;Y;oxidation;high-temperature oxidation;possible scaling modes;internal oxidation;oxidant pressures;h-2-h2s mixtures;sulfidation;oxygen
李鹏
,
胡耀波
,
熊惟皓
,
林真
硬质合金
doi:10.3969/j.issn.1003-7292.2000.02.001
研究了稀土元素Y对Ti(C,N)基金属陶瓷微观组织和性能的影响.Y在Ti(C,N)基金属陶瓷中可以起到净化粘结相/硬质相界面的作用,并使其包覆层的厚度略有增加,从而使硬质相颗粒得到细化.当Y含量为0.8wt%时细化效果最明显,此时Ti(C,N)基金属陶瓷的抗弯强度和硬度值最大.
关键词:
稀土元素
,
Y
,
金属陶瓷
,
组织与性能
Journal of Applied Physics
The magnetic properties of R2Co14B1-xCx (x=0, 0.5 and R=Y, Sm) compounds have been studied by measuring the temperature dependence of the easy- and hard-magnetization curves on magnetically aligned samples between 1.5 and 300 K for Y2Co14(B,C) and at 4.2 K for Sm2Co14(B,C). The magnetic anisotropy of Y2Co14B increases due to the substitution of C for B, whereas the saturation magnetization decreases. Between 1.5 and 300 K, the anisotropy field of Y2Co14B0.5C0.5 increases about 2 T and the Co moment decreases about 0.05mu(B). The anisotropy field Of Sm2Co14B also increases upon C substitution and the saturation magnetization decreases slightly. The ac susceptibilities of both SM2Co14B and Sm2Co14B0.5C0.5 exhibit anomalies that may arise from a spin reorientation within the basal plane.
关键词:
nd2fe14b;exchange;nd2co14b;r2fe14b;field
Physics Letters A
The magnetic properties of the mixed ferro-ferrimagnetic compounds with (A(a)B(b)C(c))(y)D, in which A, B, C and D are four different magnetic ions and form four different sublattices, are studied by using the Ising model. And the Ising model was dealt with standard mean-field approximation. The regions of concentration in which two compensation points or one compensation point exit are given in c-a, b-c and a-b planes. The phase diagrams of the transition temperature T-c and compensation temperature T-comp are obtained. The temperature dependences of the magnetization are also investigated. Some of the result can be used to explain the experimental work of the molecule-based ferro-ferrimagnet ((NiaMnbFecII)-Mn-II-Fe-II)(1.5) [Cr-III (CN)6] - zH(2)O. (C) 2003 Elsevier B.V. All rights reserved.
关键词:
mixed ferro-ferrimagnet;Ising model;four sublattices;phase diagram;transition temperature;compensation temperature;magnetic-properties;prussian blue;alloy
