L.Li 1)
,
Z. P.Wang. 2)
,
Z.K.Qu 1)
,
D.M.Jia 3) and Z.Jiang 4) 1) Mechanical Engineering College
,
Shenyang University
,
Shengyang 110044
,
China 2) Harbin Research Institute of Welding
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Harbin 150080
,
China 3) Information Engineering Collage
,
Shenyang University
,
Shengyang 110044
,
China 4) Materials Engineering College
,
University of Science and Technology Beijing
,
Beijing 100083
,
China
金属学报(英文版)
A novel test method of measuring the interface bond strength between a thermal sprayed coating and substrate is put forward first in this paper. The test method is simple and reliable, and exists no any inherent shortcoming and controversy. The interface bond strength obtained by the test method is completely the inherent property of the interface and depends only on coating material properties, spray conditions, and technique of depositing the coating. By extensive tests, it is shown that the test tesults are very tepeatable and reliable. Furthermore, from this test, the critical coating thickness under which the coating spall can not emerge is also obtained.
关键词:
coating
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null
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B.W. Wang
,
H. Shen
金属学报(英文版)
Ni-Cr System solar selective thin solid films were prepared by d.c. magnetron reactivesputtering under the atmosphere of O2 and N2. Ni-Cr alloy was chosen as targetmaterial and copper sheets as substrate. Using SEM, Spectrophotometer and Talystepto analyze the relations between the selective characteristic and the structure, theformation and the thickness of the thin films. The aim is to obtain good solar selectivethin films with high absorptance and low emittance, which is applied to flat plate solarheat collectors.
关键词:
solar selective thin film
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null
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null
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Chunli YANG
,
Sanbao LIN
,
Fengyao LIU
,
Lin WU
,
Qingtao ZHANG
材料科学技术（英文）
The mechanism of penetration depth increased by activating flux in activating tungsten inert gas (A-TIG) welding was studied by measuring the distribution of trace element Bi in the weld and monitoring the change of arc voltage during A-TIG welding of stainless steel 0Cr18Ni9 with fluxes SiO2 and TiO2. The results show that the mechanism of penetration depth in A-TIG welding depends on the sort of flux used. The weld pool convection after coating the flux SiO2 and flux TiO2 is changed inversely compared with convectional TIG welding without flux. The arc voltage is increased by flux SiO2 whilst flux TiO2 does not have effect on the arc voltage. The reason of penetration depth increase for SiO2 is due to the constriction of arc plasma and the change of surface tension gradient. The increase of weld penetration depth with TiO2 only ascribes to the change of surface tension gradient.
关键词:
TIG welding
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null
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null
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MA Zongyi YAO Zhongkai Harbin Institute of Technology
,
Harbin
,
China
金属学报(英文版)
The SiC_w/Al composite prepared by squeeze casting has a combination of superior room temperature specific strength and modulus together with excellent thermal properties.The extrusion can make an improvement on the strength and ductility of the composite from 582 MPa as squeeze casted up to 639 MPa,and on the transformation from isotropic to the anisotropic structure.This seems to be explained by the orientation of whiskers and the densification of dislocations in matrix.TEM observation indicates that the stacking fault is the usual planar defect on the SiC_w surface. composite;;SiC whisker;;Al alloy;;microstructure
关键词:
composite
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null
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null
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P.Y.Zong and L.R.Zhang Mechanical Engineering College
,
Shenyang University
,
Shenyang 110044
,
China
金属学报(英文版)
The Authors of this Article have done research on the cracking resistance of cold welding surfacing electrodes for blast furnace valves by adjusting the basicity of slag component, decreasing the hydrogen content and improving microstructure. The DF 2 Cold Welding Surfacing Electrodes prove to possess the following characters: 1) Excellent cracking resistance for surfacing alloys at normal temperature. 2) Excellent cracking resistance for repair welding and rewelding. 3) Excellent machinability for surfacing alloying.
关键词:
cold welding
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null
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null
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WU Chuansong
,
CAO Zhenning
,
WU Lin Harbin Institute of Technology
,
Harbin
,
China
金属学报(英文版)
A model is established to analyze three-dimensional fluid flow and heat transfer in TICweld pools with full penetration.It considers the deformation of the molten pool surfaceat the condition of full penetrated workpieees,takes the are pressure as the drivingforce of the pool surface deformation,and determines the surface configuration of weldpool based on the dynamic balance of arc pressure,pool gravity and surface tension atdeformed weld pool surface. The SIMPLER algorithm is used to calculate the fluid flowfield and temperature distribution in TIG weld pools of stainless steel workpieces.TIGwelding experiments are made to verify the validity of the model.It shows the calculatedresults by the model are in good agreement with experimental measurements. professor,Dept of Welding Engineering,Harbin Institute of Technology,Harbin 150006,China
关键词:
KEY WORDS TIG weld pool
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null
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S. J. Chen
,
S. Y. Yin
,
L. Feng and L. Y. Li( 1) School of Materials Science and Engineering
,
Beijing Polytechnic University
,
Beijing 100022
,
China 2)National Key Laboratory of Advanced Welding Production Technology
,
HIT
,
Harbin 150001
,
China)
金属学报(英文版)
Based on the existing component models in the Pspice software package, a combined model for Insulat- ed the Bipolar Transistor (IGBT) is established, in which a non - linear is introduced to represent the parasitic capacitance. Using this model, computerized simulation is conducted for the FB - ZVZCS - PWM soft - ewitching converter,the switching and energy-transferring characteristics of the components are analyzed.The simulation results are testified by experiments.It is proved that by abopting appropriate models,computerized simulation becomes an effective tool for investigation of arc welding inverter power source.
关键词:
arc welding inverter
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null
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