检索结果-南通市图书馆

Mechanism of liquid zinc corrosion on metals

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and materials 1997年第3期11卷 22-26页

作者： CAO Xiaoming , LONG Yi wang Run2 (Department of materials and science, Hebei {3. of technology, Tianin 3.013., china) (materials science and engineering school, {3. of science and technology Beijing, Beijing {13. china)

Two kinds of materials, soluble and insoluble in liquid zinc, such as Fe and FeB, are separately dealt with.A new theory is presented for insoluble materials. Based on the theory, the surface defects of insoluble mate... 详细信息

关键词： liquid zinc corrosion mechanism boronize

Hydraulic fracturing behaviors of shale under coupled stress and temperature conditions simulating different burial depths

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining science and technology 2024年第6期34卷 783-797页

作者： Qin Zhou Zheming Zhu Wei Liu Huijun Lu zidong Fan Xiaofang Nie Cunbao Li Jun wang Li Ren MOE Key Laboratory of Deep Earth science and engineering College of Architecture and EnvironmentSichuan UniversityChengdu 610065China Downhole Operating Company CNPC Chuanqing Drilling and Exploration Engineering Co.Ltd.Shenzhen 518060China school of Architecture and Civil engineering Xihua UniversityChengdu 610065China Guangdong Provincial Key Laboratory of Deep Earth sciences and Geothermal Energy Exploitation and Utilization Shenzhen UniversityShenzhen 518060China

Fracture propagation in shale under in situ conditions is a critical but poorly understood mechanical process in hydraulic fracturing for deep shale gas reservoirs. To address this, hydraulic fracturing experiments were conducted on hollow double-wing crack specimens of the Longmaxi shale under conditions simulating the ground surface(confining pressure σ_(cp)=0, room temperature(Tr)) and at depths of 1600 m(σ_(cp)=40 MPa, Ti=70 ℃) and 3.00 m(σ_(cp)=80 MPa, high temperature Ti=110 ℃) in the study *** in situ stress was found to significantly increase fracture toughness through constrained microcracking and particle frictional bridging mechanisms. Increasing the temperature enhances rather than weakens the fracture resistance because it increases the grain debonding length, which dissipates more plastic energy and enlarges grains to close microdefects and generate compressive stress to inhibit microcracking. Interestingly, the fracture toughness anisotropy in the shale was found to be nearly constant across burial depths, despite reported variations with increasing confining pressure. Heated water was not found to be as important as the in situ environment in influencing shale fracture. These findings emphasize the need to test the fracture toughness of deep shales under coupled in situ stress and temperature conditions rather than focusing on either in situ stress or temperature alone.

关键词： Hydraulic fracturing Fracture toughness Shale Anisotropy Deep rock mechanics

Laser Shock Processing of an Austenitic Stainless Steel and a Nickel-base Superalloy

在线全文

学校读者我要写书评

暂无评论

Journal of materials science & technology 2003年第5期19卷 402-404页

作者： Huaming wang, Xijun SUN and Xiaoxuan LILaboratory of Laser materials Processing and Surface engineering, {3. of materials science and engineering, Beihang university (formerly Beijing university of Aeronautics and Astronautics), Beijing 100083. china Lab. of Laser Mat. Proc. Sch. of Mat. Sci. and Eng. Beijing Univ. of Aero. and Astron. Beijing 100083 China

An austenitic stainless steel 1Cr18Ni9Ti and a solid solution-strengthened Ni-base superalloy GH3. were shock processed using a Q-switched pulsed Nd-glass laser. Microstructure, hardness and residual stress of the laser shock processed surface were investigated as functions of laser processing parameters. Results show that high density of dislocations and fine deformation twins are produced in the laser shock processed surface layers in both the austenitic stainless steel and the nickel-base superalloy. Extensive strain-induced martensite was also observed in the laser shock processed zone of the austenitic steel. The hardness of the laser shock processed surface was significantly enhanced and compressive stress as high as 400 MPa was produced in the laser shock processed surface.

关键词： Laser shock processing Austenitic stainless steel Nickel-base superalloy Surface mechanical properties Residual stress

Application of Potentiostats Using PC in the Phase Analysis of Galvano-Chemis-try

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and materials 2000年第2期14卷 151-153页

作者： Bo Wen Xinyu Liu Xinhua wang Wanjun wang Xang Ma(Information engineering {3., university of science and technology Beijing, Beijing 100083. china)(Metallurgy {3., university of science and technology Beijing, Beijing 100083. china)(Beijing Resea Univ Sci & Technol Beijing Informat Engn Sch Beijing 100083 Peoples R China Univ Sci & Technol Beijing Met Sch Beijing 100083 Peoples R China Beijing Res Inst Iron & Steel Beijing 100081 Peoples R China

A set of device is designed based on PC to realize the functions of traditional potentiostats in the phase ana1ysis of galvanochemistry. In the device, A/D and D/A conversion is used to measure the electrode potential and convert the voltage for outPut; specific program runs in the PC to regulate and control the system. The effect of the proportion factor Kp on the control variation is researched through certain experiment. Two experiments, the control of electrolysis in constant poteniial and the determination of polarization curves, are designed to test and evaluate the effectiveness of the device. The experimemel results show that the variation between the actualanode potential and the target potential could be controlled to below 1 mV if Kp is set to an appropriate value.

关键词： potentiostat PC phase analysis of galvano-chemistry

Mechanical Properties and Erosive Wear Resistance of Zirconia Toughened Al_2O_3.TiC Ceramics

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and materials 2000年第2期14卷 110-114页

作者： Lihua Xu Fang Lian Yuyan Guo Qiang Zhen Jose Maria Fonte Ferreira Fuming wang Wenchao Li(Material science and engineering {3., university of science and technology Beijing, Beijing 100083. china)(Metallurgy {3., university of science and Tech Material science and engineering school University of Science and Technology Beijing Beijing 100083 China Metallurgy school University of Science and Technology Beijing Beijing 100083 China Department of Ceramic and Glass engineering University of Aveiro 3810-193 Aveiro Portugal

The effect of ZrO2, content on the fracture toughness, flexural strength and Vickers hardness as well as the erosive wear resistan properties of zirconia toughened Al2O3.TiC ceramic composites has been investigated. The results showed that the improvement in fracture toughness and flexure strength of composites with the content of zirconia less than 50% and 10% in mass fraction respectively,is primarily attributed to stress-induced transformation toughening by the analyse of X-ray diffraction. The dependance of erosion wear resistance on the attak angle and the content of ZrO2, panicles of the composites was also revealed. It is found that the erosion rate of the composites has a sharp rise at a attack angle over 65°. This phenomenon is due to a brittle response to the erosion test by microsmictural observation on eroded surface.

关键词： mechanical properties, erosion ceramic composites

Fabrication and magnetic properties of Sm_3.Fe,Ti)_(29)N_x/α-Fe dual-phase nanocomposite permanent magnetic material

在线全文

学校读者我要写书评

暂无评论

science china(Technological sciences) 2007年第2期50卷 184-189页

作者： CUI ChunXiang, ZHANG Ying, SUN JiBing & wang Ru school of materials {3. and engineering, Hebei university of technology, Tianjin 3.013., china 1. school of materials science and {3. Hebei University of Technology Tianjin 300130 China

Sm3.Fe,Ti)29Nx/α-Fe dual-phase nanometer magnetic material was fabricated through rapid solidification, crystallization and nitridation of Sm-Fe (Ti) alloy. The effect of combination of rapid solidification and Ti alloy addition on the phase for- mation and microstructure of the Sm-Fe alloy is investigated in this paper. The mi- crostructure of amorphous phase and dual-phase nano-grain crystals before and after crystallization annealing were observed using a high-resolution transmission electron microscope (HREM). The dual-phase nano-grains after annealing were compacted together with a clear interface with the direct exchange-coupling mechanism. Different annealing processes were used to examine the melt-spun alloy. Comparison of the images of SEM showed that annealing at 750 ℃ for 10 min was most suitable to get homogeneous and nano-grains. No obvious kink was de- tected in the second quadrant of the hysteresis loop like a single hard magnet, and strong exchange coupling was found between hard magnets and soft magnets.

关键词： rapid solidification microstructure Sm3.Fe Ti)29Nx/α-Fe dual phase nanocomposite exchange-coupling

Research on the Long Time Swelling Properties of Poly (vinyl alcohol)/Hydroxylapatite Composite Hydrogel

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic engineering 2009年第1期6卷 22-28页

作者： De-kun Zhang~(1,3., Da-gang wang~2, Jun-jie Duan~(1,3., Shi-rong Ge~(2,3.1. school of materials {3. and engineering, china university of Mining and technology, Xuzhou 221116, P. R. china2. school of Mechanical and Electrical engineering, china university of Mining and technology, Xuzhou 221116, P. R. china3. Biotribology Center, National Key Laboratory of Tribology, Tsinghua university, Beijing 100083. P. R. china [a]school of materials science and {3. China University of Mining and Technology Xuzhou 221116 P. R. China [b]School of Mechanical and Electrical Engineering China University of Mining and Technology Xuzhou 221116 P. R. China [c]Biotribology Center National Key Laboratory of Tribology Tsinghua University Beijing 100083 P. R. China

Poly(vinyl alcohol)/hydroxylapatite(PVA/HA)composite hydrogel was prepared by repeated freezing and *** water loss properties of the resultant hydrogel were investigated by using optical *** time immersion tests of PVA/HA composite hydrogel were carried out in the diluted calf serum solution to study the change laws of swelling properties with the freezing-thawing cycles and HA *** micro-morphologies of PVA/HA composite hydrogel after long time immersion were observed by means of the high-accuracy 3. *** results show that the swelling process of PVA/HA composite hydrogel is the converse process of its water *** time swelling ratio curves of PVA/HA composite hydrogel in the calf serum solution are manifested as four stages of quick increase,decrease,slow decrease and stable balance,and its equilibrium swelling ratio decreases with the increase of freezing-thawing cycles and HA *** is revealed that the network structure of the composite hydrogel immersed for a long period is significantly improved with the increase of HA content. Perfect network structures of PVA/HA composite hydrogel as well as full and equilibrium tissues after swelling equilibrium are obtained when the HA content is 3. and the number of freezing-thawing cycles is 7.

关键词： poly (vinyl alcohol) hydroxyapatite composite hydrogel swelling property morphology

Modified HDDR Process for Producing Anisotropic NdFeB Powders

在线全文

学校读者我要写书评

暂无评论

Journal of university of science and technology Beijing 2001年第2期8卷 111-114页

作者： Xubo Liu, Yue Ming, Yaofu Xiao, Qi Zeng, Zhengyi Zhang, Run wang (Material science and engineering {3., university of science and technology Beijing, Beijing 100083. china) (Beijing Institute of Aeronautical materials, Beijing 100095, china) Univ Sci & Technol Beijing Mat Sci & Engn Sch Beijing 100083 Peoples R China Inst Aeronaut Mat Beijing 100095 Peoples R China

The effect of HDDR (hydrogenation-decomposition-desorption-recombination process) treating conditions on magnetic anisotropy of Nd13.ebalCo17B7Ga1Zr0.1 powders has been studied. It is found that increasing recombination temperature is effective for magnetic anisotropy formation, but at the cost of reducing the coercive force. The microstructure analysis (TEM) indicates that the NdFeB recombination nucleation takes place markedly during the transition range from decomposition stage to recombination stage, in which both temperature and H-2 pressure change sharply. In order to create a more stable treatment condition for recombination nucleation, a modified HDDR process is established in which the conventional continuous transition range is divided into several stages. The experimental results have proved that such a process can effectively enhance the remanence of the magnet powders with high certainty, while only cause a little reduction in coercivity.

关键词： HDDR anisotropy NdFeB

Thermal stability of nanocrystalline W-Ti diffusion barrier thin films

在线全文

学校读者我要写书评

暂无评论

science china(Technological sciences) 2010年第4期53卷 1049-1055页

作者： wang QingXiang,FAN ZhiKang & LIANG ShuHua school of materials {3. and engineering,Xi’an university of technology,Xi’an 710048,china 1. school of materials science and {3. Xi’an University of Technology Xi’an 710048 China

Nanocrystalline W-Ti diffusion barrier thin films with different phase structures and Cu/barrier/Si multilayer structures were deposited on p-type Si(100) substrates by DC magnetron *** films were annealed at different temperatures for 1 *** diffusion barrier properties and thermal stability were studied using four-probe tester(FPP),XRD,AFM,XPS,FESEM,and *** experimental results showed that the films were stable up to 700℃.When the annealing temperature was increased,the Cu and Ti atoms began to react and CuTi3.was *** addition,the high resistance Cu3.i was formed due to inter-diffusion between the Si and Cu atoms which made the surface rougher and caused the sheet resistance to increase *** the same time,failure mechanism of the nanocrystalline W-Ti diffusion barrier thin films during annealing process was also discussed.

关键词： nanocrystalline W-Ti thin films diffusion barrier anneal sheet resistance