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Journal of Materials science & technology 2010年第11期26卷 996-1000页

作者： Lihong Xue and Youwei Yan state key {2. of Materials {3. and die and mould technology,huazhong university of science and technology,wuhan {12.,{13. [a] state key {2. of Materials {3. and die and mould technology huazhong university of {2. and {3. wuhan 43.074 china

Highly oriented barium titanate （BaTiO 3. thin films on Pt substrate were fabricated by combination of electrophoretic deposition with hydrothermal *** structure and morphology of thin films were characterized by X-ray diffraction and field-emission scanning electron *** is found that the titania precursor film,Ba（OH）2.concentration and hydrothermal temperature play crucial roles in the film morphology and *** BaTiO3.thin films with highly （110） preferred orientation can be formed on polycrystalline Pt substrate by appropriate adjustment of the reaction *** orientation parameter f of highly oriented BaTiO3.films was up to *** films exhibited a smooth and crack-free surface and remained in the layered *** situ topotactic transformation and dissolution-crystallization mechanisms were proposed to explain the morphology and orientation of BaTiO3.films during hydrothermal treatment.

关键词： Barium titanate Preferred orientation Electrophoretic deposition Hydrothermal treatment

HCWCI/Carbon Steel Bimetal Liner by Liquid-Liquid Compound Lost Foam Casting

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Journal of Iron and Steel Research International 2012年第10期19卷 13-19页

作者： XIAO Xiao-feng1,2. YE Sheng-ping2. YIN Wei-xin3. XUE Qiong4 (1. School of Mechanical Engineering and Automation, wuhan Textile {3., wuhan 43.073. hubei, china 2. state key laboratory of Material processing and die and {13. technology,{12., wuhan 43.074, hubei, china 3. wuhan Zhike Abrasive-Resistant Material science and technology Development Co Ltd, wuhan 43.073. hubei, china 4. College of science, wuhan {3. of technology, wuhan 43.079, hubei, china) [a] School of Mechanical Engineering and Automation Wuhan Textile University Wuhan 430073 Hubei China [b] state key {2. of Material {3. and die and mould technology Huazhong University of Science and Technology Wuhan 430074 Hubei China [c] wuhan Zhike Abrasive-Resistant Material science and {2. Development Co Ltd Wuhan 430073 Hubei China [d] College of science Wuhan University of Technology Wuhan 430079 Hubei China

Impact, friction and corrosion from the grinding balls and the grinding medium during the mineral processing result in liner breakage. Liner, made from Hadfield steel or alloyed steel, could not have served in wet grinding environment for more than ten months. Composite liner, made from HCWCI (high Cr white cast iron) and carbon steel, has been developed successfully with liquid-liquid composing process based on LFC (lost foam casting). The microstructure of composite was analyzed with optical microscope, SEM (scanning electron microscope)/EDX energy-dispersive X-ray and XRD (X-ray diffraction). According to micrograph, the combination region of two metals was staggered like dogtooth, no mixtures occurred between two liquid metals, and its interface presented excellent metallurgical bonding state. The results of mechanical property test show that, the hardness of HRC, the fracture toughness, and the bending strength are more than 61, 16.5 J/cm2.and 1 600 MPa, respectively. Comparison between liners made from bimetal composite and alloyed steel has also been investigated in industrial hematite ball mill. The results of eight months test in wet grinding environment prove that the service life of bimetal composite liner is three times as long as that of one made from alloyed steel.

关键词： composite liner bimetal liquid-liquid compound composite interface lost foam casting high Cr white cast iron

Microstructure and shear strength of the brazed joint of Ti(C,N)-based cermet to steel

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Rare Metals 2010年第1期29卷 72-77页

作者： YE Dameng, XIONG Weihao, Zhang Xiuhai, QU Jun, and YAO Zhenghua state key {2. of Plastic Forming Simulation and {3. & mould technology, huazhong university of science and technology, wuhan 43.074, china state key {2. of Plastic Forming Simulation and {3. & mould technology Huazhong University of Science and Technology

Firm joins were obtained between Ti（C,N）-based cermet and steel with Ag-Cu-Zn-Ni filler metal by vacuum brazing. The effects of technological parameters such as brazing temperature, holding time, and filler thickness on the shear strength of the joints were investigated. The microstructure of welded area and the reaction products of the filler metal were examined by scanning electron microscopy （SEM）, metallographic microscope （OM）, energy-dispersive X-ray analysis （EDS）, and X-ray diffraction （XRD）. The brazing temperature of 870℃, holding time of 15 min, and filler thickness of 0.4 mm are a set of optimum technological parameters, under which the maximum shear strength of the joints, 176.5 MPa, is achieved. The results of microstructure show that the wettability of the filler metal on Ti（C,N）-based cermet and steel is well. A mutual solution layer and a diffusion layer exist between the welding base materials and the filler metal.

关键词： Ti(C,N)-based cermet vacuum brazing filler metal shear strength interface structure

Effect of bonding process on the properties of isotropic epoxy resin-bonded Nd-Fe-B magnets

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Rare Metals 2009年第3期28卷 248-252页

作者： ZHANG Xiuhai XIONG Weihao state key {2. of Material {3. and die ＆ mould technology Huazhong University of Science and Technology Wuhan 430074 China

Bonded NdFeB magnets were prepared by compression molding. The effect of preparation technology on their magnetic and mechanical properties was studied through the analysis of density, Br, Hcj, （BH）max, bending strength, and compressive strength of the bonded magnets. The results showed that the magnetic properties decreased with increasing binder content, whereas the mechanical properties increased. Br and （BH）max increased with rising pressure, whereas Hcj decreased. For a fixed mass fraction of the binder, the optimal pressure was 62. MPa and the best thermosetting temperature was 160°C. These conditions made the bonded magnets have the optimal mechanical properties. Scanning electron microscopy （SEM） analyses of the fracture surfaces indicated that the epoxy resin bonded magnets exhibited brittle behavior.

关键词： Nd-Fe-B bonded magnets magnetic properties mechanical properties brittle behavior epoxy resin

Structure and Properties of TiB_2.Thin Films Deposited at Low Temperatures Using RF Magnetron Sputtering

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Journal of wuhan university of {2.(Materials {3.) 2008年第5期23卷 666-669页

作者：戴伟张同俊 state key Lab of Material {2. and {3. & mould technology Huazhong University of Science and Technology

The TiB2.thin films were deposited on steel substrates using RF magnetron sputtering technique with the low normalized substrate temperature （0.1〈Ts/Tm〈0.2.. Microstructure of these films was obtained by field emission scanning electron microscope （FESEM） and the grazing incidence X-ray diffraction （GIXRD） characterization, while the composition of films was obtained using Auger emission spectroscopy （AES） analysis. It was found that the TiB2.thin films were overstoichiometric with the B/Ti ratio at 2.3. and the diffusion of Ti and B atoms on the substrate surface was greatly improved at 3.0 ℃. Moreover, a new dense structure, named ＂equiaxed＂ grain structure was observed by FESEM at this substrate temperature, Combined with FESEM and AES analysis, it was suggested that the ＂equiaxed＂ grain structure was located in Zone 2.at the normalized substrate temperature as low as 0.18.

关键词： TiB2.thin films structure zones 1,2.T equiaxed structure superhard coating auger electron spectroscopy

Grain Refining Performance of SHS Al-50TiC Master Alloys for Commercially Pure Aluminum

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Journal of wuhan university of {2.(Materials {3.) 2002年第3期17卷 13-16页

作者：严有为 huazhonguniversityof{2.and{3.

An Al 50wt%TiC composite was directly synthesized by self propagating high temperature synthesis (SHS) technology,and then was used as a grain refining master alloy for commercially pure *** microstructure and grain refining performance of the synthesized master alloy were emphatically *** SHS master alloy only contained submicron TiC particles except for Al ***,TiC particles were relatively free of agglomeration. Grain refining tests show that adding only 0.1 wt% of the master alloys to the aluminum melt could transform the structure of the solidified samples from coarse columnar grains to fine equiaxed grains (average grain size 12.μm),and that this grain refining effectiveness could be maintained for almost 1.5h at 1003.. Therefore,it is concluded that the SHS master alloy is an effective grain refiner for aluminum and its alloys, and that it is highly resistant to the grain refining fading encountered with most grain refiners.

关键词： SHS Al TiC composite grain refiner microstructure grain refinement

Fabrication and Microstructure Evolution of Niobium-Niobium Silicide Composites by Spark Plasma Sintering

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Journal of wuhan university of {2.(Materials {3.) 2007年第2期22卷 299-302页

作者：陈哲严有为 state key Lab of {2. & {3. technology Huazhong University of Science & Technology

By using Nb and Si elemental powders as raw materials, dense Nb/NbsSi3.composites were successfully fabricated by a spark plasma sintering （SPS） technology. The microstructure of the fabricated composites was analyzed by OM, SEM, XRD and EPMA; the microstructure evolution of the composites was also investigated by a quenching test. The experimental results show that the prepared composites consist of Nb and Nb5Si3.phases; Nb particle uniformly distributes in the in-situ synthesized Nb5Si3.matrix. During the SPS process, an interfacial reaction occurs between Nb and Si particles to synthesize Nb5Si3.until reactant silicon has been completely depleted.

关键词： spark plasma sintering Nb/Nb5Si3.composites fabrication microstructure evolution

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机械驱动下Ta-N_2.化反应的研究

物理学报 2002年第3期51卷 603-608页

作者：柳林华中科技大学材料科学与工程学院模具技术国家重点实验室武汉430074

借助X射线衍射和透射电子显微镜研究了在机械驱动下难熔金属Ta与N2.的氮化反应 .实验发现 ,在室温下的高能球磨可实现Ta N2.反应 ,并形成三种不同结构的氮化物 :六方结构的Ta2.N ,四方结构的Ta3.N5和非晶相 .研究表明 ,N2.在清洁的金属... 详细信息

借助X射线衍射和透射电子显微镜研究了在机械驱动下难熔金属Ta与N2.的氮化反应 .实验发现 ,在室温下的高能球磨可实现Ta N2.反应 ,并形成三种不同结构的氮化物 :六方结构的Ta2.N ,四方结构的Ta3.N5和非晶相 .研究表明 ,N2.在清洁的金属表面上发生可离解式的化学吸附是Ta N2.反应的基本过程 ,高的Ta—N键合能是N2.分子在Ta表面上发生化学吸附的热力学驱动力 ,而球磨在金属粉末中引入的储能 (界面能和缺陷能 )为Ta—N向金属氮化物转变提供了激活能 .球磨后期非晶相的形成则源于Fe的侵入 ,所形成的非晶相含有Ta Fe N三种元素 .

关键词：机械驱动 Ta/N2.化反应热力学动力学钽氮气高能球磨固态-气态反应微观机制

Effects of molybdenum on the microstructure and mechanical properties of Ti(C,N)-based cermets with low Ni

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Rare Metals 2006年第1期25卷 90-95页

作者： WANG Saiyu XIONG Weihao YAN Mingshuang FAN Chou The Stale key laboratory for {2. ＆ {3. technology Huazhong University of Science and Technology Wuhan 430074 China Huangshi Institute of technology Huangshi 435003 China

The effects of Mo on the microstructure and mechanical properties of Ti（C,N）-based cermets with low Ni have been studied systematically. Different contents of Mo （4-12.wt.%） were added into Tl（C,N）-based cermets. Specimens were fabricated by conventional powder metallurgy and vacuum sintered at temperatures of 1440, 1450, and 1460℃ individually. The microstructure and fracture morphology were investigated by scanning electron microscope, and the mechanical properties such as transverse strength and hardness were measured. The results show that the microstructure is uniform and the thickness of rim phase is moderate when the content of Mo is 8 wt.%; the mechanical properties of the specimens sintered at 1450℃ are better than those sintered at 1440 and 1460℃. The integrated properties of transverse strength and hardness are the best when the content of Mo is 8 wt.% and the sintering temperature is 1450℃.

关键词： Ti(C,N)-based cermets microstructttre mechanical properties Mo content

Effect of hot isostatic pressing nitrogen on the microstructure and properties of a Ti(C,N)-based cermet

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Rare Metals 2006年第4期25卷 321-325页

作者： YAN Xianmei XIONG Weihao YANG Yong ZHENG Liyun state key {2. of {3. and mould technology Huazhong University of Science and Technology Wuhan 430074 China

The high-temperature, high-pressure hot isostatic pressing technology was used for depositing hard coatings on Ti（C, N）-based cermets. The rnicrostructure and properties of the sample were investigated using optical microscopy, scan- ning electron microscopy, X-ray diffraction, electron probe microanalysis, and microhardness tester. The results showed that the rich titanium and nitrogen in surface zone were induced by the heat treatment. The high nitrogen activity of the surface region was the driving force for outward transport of titanium and inward transport of tungsten in the cobalt binder. The toughness and hardness were improved and a hardness gradient was formed. It is the high-temperature, high-pressure N2.that enables closure of holes, thereby alleviating defects and prolonging tool life.

关键词： Ti(C, N)-based cermet hot isostatic pressing microstructure properties