- Issue 8,2003 Table of Contents
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2003(8):577-584.
Abstract:Current situation and prospect for titanium industry in America, Japan and China is briefly reviewed. Chracteristics in aspects of Ti resources, production of Ti sponge and Ti materials, Ti application development, research and development of Ti alloys, are compared.
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Wang Junzhong , Hu Yuan , Chen Zuyao
2003(8):585-590.
Abstract:結(jié)合相關(guān)的理論基礎(chǔ)，綜述了超聲化學(xué)制備納米材料的研究進(jìn)展。主要涉及采用和發(fā)展多種前驅(qū)物聲化制備無(wú)機(jī)納米材料，特別是超聲電沉積法制備納米粉體新技術(shù)及超聲制備無(wú)機(jī)-有機(jī)納米復(fù)合材料等的進(jìn)展；并展望了今后的研究方向。
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Xu Qingyan , Feng Weiming , Xiong Shoumei , Liu Baicheng
2003(8):591-595.
Abstract:Microstructure modeling of aluminum alloy castings has been carried out by using a new stochastic modeling methods coupled with macro heat transfer calculations. The actual dendritic shape is substituted for the square envelope in the cellular automaton model. A physical model and a mathematical model for the simplified dendrite shape are established in the paper, in which a shape function is presented to describe the dendrite shape contour. On the basis of the simplified grain shape, a coordinate transformation method is used to describe the equiaxed grain growth in the undercooled melts and the node capturing during the further growth of a grain. A continuous nucleation model is applied to deal with heterogeneous nucleation phenomenona. Dendrite tip growth kinetics and preferential <100> crystallographic orientation are taken into account. The stochastic nature of nucleation process as well as the deterministic of dendrite growth is considered to simulate the crystal growth. A microstructure simulation scheme is developed to model the grain formation according to the above model. Two- dimensional calculations are performed to simulate the evolution of equiaxed dendritic morphologies. In order to verify the modeling results, sample castings are cast in sand molds and metal molds. Simulation results show that grain size is smaller for metal mold casting, but larger for sand mold casting, in good agreement with both the experimental results and the postulated solidification mechanism.
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Liu Yudong , Cui Jianguo , Ma Jusheng
2003(8):596-599.
Abstract:To study the effect of substrate materials on the texture of magnetron sputtered indium, the UBM(Under Bump Metallization) of Cr/Au film, single crystal (111) InSb and amorphous photoresist were employed as substrate materials. The results indicate that the patterns of the indium textures are almost independent of the substrate materials, and the texture components consist of a strong (101) fiber texture and a weak (110) fiber texture. The texture mode proves that the texture forming mechanism of indium is a growth competition phenomenon.
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2003(8):600-603.
Abstract:根據(jù)Kohler三元溶體模型和Miedema二元系統(tǒng)生成熱模型，建立了計(jì)算三元合金及金屬間化合物各組分活度系數(shù)的方程，不僅能處理三元合金及金屬間化合物體系，也能處理二元系，甚至可以近似處理多元系。計(jì)算了Ti-5Al-2．5Sn，Ti-6Al-4V，Ti-25V-15Cr-0．2Si及TiAl中各組分的活度系數(shù)并與有關(guān)實(shí)驗(yàn)值進(jìn)行對(duì)比，發(fā)現(xiàn)根據(jù)本研究公式計(jì)算的結(jié)果比非對(duì)稱計(jì)算公式獲得的結(jié)果更符合實(shí)際。將計(jì)算結(jié)果應(yīng)用于鈦基復(fù)合材料的界面反應(yīng)研究，可以預(yù)測(cè)到：SiC／Ti-6Al-4V基復(fù)合材料的界面反應(yīng)較嚴(yán)重，SiC／Ti-25V-15Cr—0．2Si的界面反應(yīng)較難進(jìn)行，SiC／TiAl的界面反應(yīng)程度最輕。
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Zhang Xiaoli , Lu Zhenlin , Jin Zhihao
2003(8):604-606.
Abstract:The electrical resistivity of the composite MoSi2 SiC containing various SiC contents was calculated by a topological method. The results of theory and experiment were found to be in good agreement. The researching results indicate that the electrical resisitivity of the bulk composite can be increased by increasing the volume fractions of the higher resistivity SiC phase and reducing continuity of the MoSi2. The approach described may predict the SiC volume fractions and microstructures needed to obtain some desired electrical resistivity, and may provide insights into the final microstructure.
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Zou Dening , Huang Yanlu , Liang Gongying , Su Junyi
2003(8):607-609.
Abstract:A convection/diffusion single phase governing equation was employed to deal with heat transfer and fluid flow in solid, solid liquid and liquid phase system in a description of melting and solidification. A source term method was used to deal with changes of momentum and energy in respective governing equations. Based on commercial software Phoenics which is very useful in fluid flow and heat transfer, several modules were added. A 3 D transient temperature field and velocity field simulation program was developed and used to describe the laser cladding synthesis TiCp/Al composite material. A ZL104 specimen was taken as an example, to clad TiCP/Al composite by laser and to calculate the process with the developed program. Calculated results were basically coincident with those measured in the experiment.
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Zhao Yongqing , Zhu Kangying , Qu Henglei , Wu Huan , Liu Caili , Li Yuelu , Zhou Lian
2003(8):610-614.
Abstract:研究了Ti-35V-15Cr(A)和Ti-25V-15Cr(B)兩合金在不同溫度、時(shí)間和拉應(yīng)力條件下熱暴露后的熱穩(wěn)定性能。結(jié)果表明，隨著熱暴露溫度升高，合金性能惡化。600℃熱暴露，B合金性能惡化的根本原因是表面氧化，A合金則是由于表面氧化與組織變化的共同作用。熱暴露時(shí)間延長(zhǎng)，合金塑性下降；熱暴露拉應(yīng)力增大，合金塑性有所提高；A合金540℃熱穩(wěn)定性較B合金差，兩合金540℃熱暴露塑性下降的主要原因來(lái)自于熱暴露過(guò)程中微觀組織的變化，其次為表面氧化。高釩含量A合金中的α相比低釩含量B合金中的α相更易聚集于晶界。晶界α相的析出和長(zhǎng)大，是合金性能惡化并發(fā)生沿晶斷裂的主要原因。
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2003(8):615-620.
Abstract:用固相反應(yīng)法制備了二元摻雜系列La2/3(CaxBa1-x)1/3MnO3(x=0,0.40,0.45,0.55,0.60,1.0)多晶材料;在77K～420K范圍內(nèi)測(cè)量了樣品的電阻和磁電阻。結(jié)果表明,所制備的系列樣品電阻率與溫度的關(guān)系具有明顯的雙電阻峰結(jié)構(gòu);在T=77K～350K范圍內(nèi),樣品均有相似的磁電阻行為:在低溫區(qū)(T
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Li Weiwen , Zhao Xinbing , Zhu Tiejun , Cao Gaoshao
2003(8):621-623.
Abstract:采用真空懸浮熔煉和真空退火方法制備了Fe1-xCoxSi2-0．1at％Cu熱電材料。試樣的微觀組織中包含大量尺寸在1μm左右的小孔和一些裂紋。輸運(yùn)特性測(cè)量結(jié)果表明，550K時(shí)摻雜載流子的熱激發(fā)達(dá)到飽和，700K以上發(fā)生本征激發(fā)現(xiàn)象。實(shí)驗(yàn)發(fā)現(xiàn)Co的最佳摻雜量為lat％左右，名義組成為Fe0.97Co0.03Si2-0．1at％Cu的試樣的熱電性能最好。
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2003(8):624-626.
Abstract:A mathematical relationship between the strength and porosity of highly porous isotropic three- dimensional reticulated metal foams under equal- speed biaxial tension was derived.It was found that the measured properties of nickel foam,for example,were well described by the formula.
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Cui Chunxiang , Shen Yutian , Xu Yanji , Li Yanchun , Wang Ru , Wang Xin , Wang Chao
2003(8):627-630.
Abstract:A K2Ti6O13 bio ceramic coating on the surface of titanium alloy TiAlxZrx- 4Snx- 3.5Nbx- 4.5 was prepared by using an in situ kneading drying calcination synthesis technique. During emersion in a simulated body liquid the microstructure, composition of phases, bonding strength between the coating and matrix, and the bio activity of the coating were evaluated. The test results indicated that the bond strength between the coating and the matrix was high enough to resist cool and hot impact during air cooling mainly as a result of the good thermal expansion match between the coating and the matrix. Rough surfaces and small holes on the Ti alloy coating provided sites for simulated bone attachment. Soaking of the coated alloy in a simulated body liquid, encouraged the active formation of a Ca P layer with a ratio of Ca and P appropriate to human bone .
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Li Anhua , Dong Shengzhi , Li Wei
2003(8):631-634.
Abstract:The bending strength of three groups of samples variously oriented with respect to the length direction of the parent bulk have been measured. The bending macrofractography was carefully observed using SEM. Both the mechanical properties and the fracture behavior of sintered NdFeB permanent magnetic materials were investigated and found to be strongly anisotropic. Intergranular fracture was the primary fracture micromechanism. Cleavage fracture has been clearly observed in the microfractography of the group of bending samples whose orientation was parallel to the length direction, and the bending strength of the corresponding samples was far lower than those of the transverse- oriented samples.
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Li Dongyun , Qiao Guanjun , Jin Zhihao
2003(8):635-638.
Abstract:Multilayer SiC/C composites were fabricated by tape casting and hot pressed sintering.The SiC layers and the graphite layers were found to be aligned alternately and reasonably uniformly and their interfaces were straight and well distinguishable. Mechanical properties were measured and the results showed that the strength of multilayer SiC/C composites was slighhtly less than, while its fracture toughness was higher than that of monolithic SiC. Multilayer SiC/C composites revealed a saw tooth load displacement curve. This was different from catastrophic fracture curve for monolithic SiC, and similar to the theoretical curve. Cracks propagated through multilayer SiC/C composites mainly along a step like paths, accompanied by crack branching, crack parallel propagation. Whisker like microcracks and cracks being absorbed at the weak interface were also observed by SEM. The toughening mechanism in multilayer SiC/C composites was attributed to a combination of all these effects.
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Wang Hongjie , Wang Yonglan , Jin Zhihao
2003(8):639-642.
Abstract:The static fatigue and cyclic fatigue behaviour of Si3N4 ceramics in different environments (air, H2O and kerosene) were studied systematically. The results show that the stress corrosion index(n) under cyclic loading is almost the same in the various medias, and much higher than that in the same media under static loading. Mechanical cycling was deduced to introduce an additional failure mechanism that caused the cyclic fatigue life to be much shorter than static fatigue life.
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Liu Yong , Yin Zhongda , Zhu Jingchuan
2003(8):643-646.
Abstract:The effects of temperature,stress and grain size on stress relaxation in the alloy TC4 have been investigated.The results show that;? the stress relaxation is sensitive to microstructure and test conditions;? increasing temperature results in higher stress relaxation rate and low relaxation limitation; ? change of initial stress also influences the stress relaxation rate and relaxation linitation; ? the fine- grain alloy has a higher stress relaxation rate than does the large- grain alloy.
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Yan Feng , Wu Kun , Zhao Min , Yang Dezhuang
2003(8):647-649.
Abstract:The effects of hot extrusion on the microstructure and tensile properties of SiCw/MB15 were investigated by means of SEM,TEM and X- ray diffraction.After hot extrusion the microstructure was found to be homogeneous and with the axes of SiC whiskers are parallel to the extrusion direction the alignment of the SiC whiskers was found to improve the mechanical properties of composite.
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Geng Zhiting , Ma Jusheng , Ning Honglong , Huang Fuxiang
2003(8):650-653.
Abstract:The package of glass sealing to metal is one sort of main packages in an integrated circuit. It is constructared in the way that the insulator consisting of the glass sealed with Kovar alloy is soldered onto copper tubular base. The failure analysis of PM hybrid integrated circuit copper power shell has been made in the present paper. According to the comparision of our sample with the same sore of sealing power tube from aboard, we put forward some proposals and give the effective way to improve the quality of products.
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Lin Meijuan , Zhang Wengong , Deng Youe , Wang Wen
2003(8):654-657.
Abstract:通過(guò)三異丙氧基鋱[Tb(OPr^i)3]與甲基丙烯酸甲酯(MMA)混合形成的凝膠體在偶氮二異丁腈(AIBN)引發(fā)下進(jìn)行原位聚合的方法獲得含鋱的聚甲基丙烯酸甲酯，用紅外光譜(IR)、動(dòng)態(tài)機(jī)械熱分析(DMTA)、熱失重(TG)、熒光光譜(FS)、溶解性等手段對(duì)其進(jìn)行表征。結(jié)果表明：Tb(OPr^i)3中的Tb^3 離子與MMA中的C=O存在很強(qiáng)的配位作用，并導(dǎo)致進(jìn)一步交聯(lián)，形成了具有交聯(lián)網(wǎng)狀結(jié)構(gòu)的含鋱聚合物。該聚合物具有優(yōu)異的耐熱性與耐溶劑性、高貯能模量、并能發(fā)射很強(qiáng)的Tb^3 離子的^5D4→^7F6，^5D4→^7F5，^5D4→^7F4，^5D4→^7F3躍遷的特征熒光。
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Zhang Dailan , Bai Xinde , Chen Baoshan , Liu Fangyan , Wu Zhiming
2003(8):658-661.
Abstract:利用微弧氧化技術(shù)，以NaOH為電解液，對(duì)Zr-4合金進(jìn)行微弧表面處理，以改善抗腐蝕性能和耐磨損性能。通過(guò)電化學(xué)極化曲線測(cè)量、往復(fù)式摩擦磨損實(shí)驗(yàn)對(duì)Zr-4合金的抗腐蝕性能、耐磨損性能進(jìn)行測(cè)試和評(píng)價(jià)。研究結(jié)果表明上述性能與基體相比有顯著提高。利用SEM觀察Zr-4合金微弧氧化膜厚約60μm，氧化膜分為疏松層和致密層兩部分，致密層約占總厚度的1／4，與基體結(jié)合緊密。XRD分析表明微弧氧化膜由四方相和單斜相二氧化鋯組成。
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Mei Yan , Jia Zhenbin , Qiu Li , Cao Jianglin , Zhang Yanfeng , Wei Yu
2003(8):662-665.
Abstract:介紹了負(fù)載不同晶型TiO2薄膜電極的制備，并研究了聚乙二醇加入量、活化條件等對(duì)不同晶型、不同形貌、不同粒徑納米TiO2薄膜電極的光電催化活性的影響。結(jié)果表明：聚乙二醇加入量有一最佳值；且納米級(jí)銳鈦礦型TiO2和金紅石型TiO2分別經(jīng)600℃和400℃煅燒后，光電催化性能最好；粒徑越小催化活性越高．當(dāng)粒徑小于25nm時(shí)，可顯示出量子尺寸效應(yīng)。
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Yao Weihua , Tang Zilong , Luo Shaohua , Zhag Zhongtai
2003(8):666-669.
Abstract:相轉(zhuǎn)移分離法是1種新穎的陶瓷粉末制備方法,能迅速有效地從溶液中分離出高度親水的氫氧化物沉淀,從而達(dá)到液-固分離的目的。本研究首次用該方法制備了8mol%氧化釔穩(wěn)定的氧化鋯(8YSZ)超細(xì)粉末。合成的8YSZ粉末具有贗立方結(jié)構(gòu),平均粒徑在20nm～30nm左右。粉末中Na和Cl的含量分別為7.05×10-6和1.414×10-4。工藝中的石油醚可以回收,回收率為80%。可以認(rèn)為,相轉(zhuǎn)移分離法是1種有廣闊應(yīng)用前景的超細(xì)陶瓷粉末制備方法。
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2003(8):670-673.
Abstract:利用掃描電鏡(SEM)、透射電鏡(TEM)、電子探針(EPMA)、能譜(EDS)和X射線衍射(XRD)技術(shù)研究了硅對(duì)定向凝固N(yùn)i3Al基合金IC6A微觀組織的影響。結(jié)果表明在IC6A合金中添加0．10％～0．20％Si(質(zhì)量分?jǐn)?shù)，下同)會(huì)使合金的枝晶間區(qū)析出塊狀的Mo1.24Ni0.76相和Mo6(Ni0.75Si0.25)7相，當(dāng)硅的添加量達(dá)到0．30％時(shí)，合金的枝晶間區(qū)除了析出這兩種相外，還有針狀的δ-NiMo相析出。這相的析出不利于合金的高溫持久性能，它們的硬度較大，只能通過(guò)孿晶的方式變形。硅有利于提高IC6A合金的高溫抗氧化性能，而對(duì)合金的抗腐蝕性能和瞬時(shí)拉伸性能無(wú)明顯影響。
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Li Shibin , Lu Zhenlin , Gao Jiqiang , Jin Zhihao
2003(8):674-676.
Abstract:Joints between reaction bonded silicon carbide and recrystallized silicon carbide have been prepared by a reaction forming method. The microstructure in the joint area and the fracture morphology were observed by optical microscopy and scanning electron microscopy respectively. The mechanical and electrical properties of the reaction formed joints were evaluated. This study suggested that a good contact interlayer could be formed between the joint and monolithic material by the described method. The flexural strength and electrical resistivity of the silicon/ silicon carbide bulk material were not affected significantly by the presence of the reaction formed joints. It is important to optimize the joining layer microstructure and composition in order to obtaining high performance joints.
