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Abstract:對(duì)厚約3pm的金屬鉬薄膜進(jìn)行低溫離子滲硫處理，得到了單質(zhì)金屬鉬與固體潤(rùn)滑劑二硫化鉬（MoS2）共存的復(fù)合固體潤(rùn)滑滲硫?qū)?。利用SEM和EDX分析了復(fù)合滲硫?qū)颖砻妗⒔孛婕澳p面的形貌及成分分布，用XPS分析了復(fù)合滲硫?qū)颖砻婊蟽r(jià)態(tài)，用納米壓痕儀測(cè)定了復(fù)合滲硫?qū)拥挠捕燃皬椥阅Ａ俊ＤΣ聊p實(shí)驗(yàn)表明，該滲硫?qū)邮且环N非常理想的摩擦表面，具有優(yōu)異的減摩耐磨抗擦傷性能。離子滲硫技術(shù)為原位合成固體潤(rùn)滑劑MoS2提供了一種新方法。

Abstract:為了改善記錄介質(zhì)的磁性能,研究了濺射Cr和CrTi底層對(duì)Co68Cr17Pt15性能的影響。發(fā)現(xiàn)在玻璃盤(pán)基和CoCrPt磁性層之間引入100nm厚的Cr底層,可使介質(zhì)矯頑力從56kA·m-1增加到127kA·m-1,同時(shí)剩磁比和矯頑力矩形比分別增加66%和74%。同時(shí)還發(fā)現(xiàn)Cr底層厚度對(duì)介質(zhì)磁性能有較大影響?？紤]到減小Cr底層和磁性層的晶格匹配,在Cr底層里添加Ti元素,當(dāng)Ti原子分?jǐn)?shù)達(dá)到1.5%時(shí),即使在室溫下濺射,薄膜也有好的面內(nèi)磁滯回線,此時(shí)矯頑力可達(dá)到160kA·m-1。X射線衍射表明在介質(zhì)中引入Cr和CrTi底層,由于薄膜能更好的沿著垂直于易磁化軸方向生長(zhǎng)而使介質(zhì)性能提高。

Abstract:The classical optical theory was introduced to calculate the interaction between laser beam and powder stream, on the basis of which the effect of powder feeding rate on the laser intensity and temperature of the particles at different sites on the surface of the workpiece was investigated. It is shown that the peak values of both laser intensity and particle temperature decrease with increasing the powder feeding rate. And simultaneously, the laser intensity distribution and the temperature of the particles at different sites on the surface of the workpiece tend to be even. It is suggested that such results should be considered in model of laser cladding due to their subtle effects on the dynamic processes in laser molten pool.

Abstract:As electric field is applied, the behaviors of micro / nano-electromechanical systems become complicated due to the unavoidable mutual actions of Casimir force, residual stresses and electrostatic force in the system. Analytical expressions of the deflection of a bridge shaped device under the mutual actions of these forces in the systems are derived. It is shown that the rather great tensile residual stress enhances wavy behavior of the deflection.

Abstract:以商業(yè)純Gd為原料,采用非自耗電弧爐氬氣保護(hù)下熔煉了Gd5Si2Ge2-xSnx(x=0.2,0.5,1)和Gd5Si2-yGe2Sny(y=0.1,0.2,0.5)系列合金,研究Sn合金化對(duì)Gd5Si2Ge2晶體結(jié)構(gòu)和磁熱性能的影響.粉末XRD結(jié)果表明Sn代Ge樣品具有正交Gd5Si4型結(jié)構(gòu);Sn少量代Si(y=0.1,0.2)的樣品具有單斜Gd5Si2Ge2型結(jié)構(gòu);Gd5Si1.5Ge2Sn0.5則為單斜和正交的混合結(jié)構(gòu).用超導(dǎo)量子磁強(qiáng)計(jì)(SQUID)測(cè)定了樣品的M-T和不同溫度的M-H曲線,結(jié)果表明Gd5Si2Ge2-xSnx(x=0.2,0.5,1)不具有巨磁熱效應(yīng);Gd5Si1 9Ge2Sn01合金的最大磁熵變達(dá)15.3 J/kg·K(0 T～5 T),具有巨磁熱效應(yīng).

Abstract:By means of growth unit of anion coordination polyhedron theory, growth units and equilibrium morphology of TiC Crystal which grew freely in titanium alloy were investigated. On the basis of the research on the characteristics of TiC crystal structure, energy level fission of orbit and bonding orbit of Ti crystal, through verifying the bonding energy released when TiC crystal formed different growth units, it can be concluded that the growth unit of TiC crystal which freely grew in molten titanium is TIC6. According to the stacking mode of the TiC6 crystal growth unit, the equilibrium morphology of TiC crystal is octahedron. However during the actual sample preparation, because of the undercooling and inhomogeneity of the solute distribution, TiC crystal may have different morphologies. Those conclusions are proved by the results of unidirectional solidification experiments in floating zone

Abstract:在氬氣氣氛中用熔煉法制備了Pr2Fe17-xCox系列合金，通過(guò)粉末X射線衍射和SQUID磁強(qiáng)計(jì)研究了樣品的結(jié)構(gòu)、磁性和磁熵變。結(jié)果表明：Pr2Fe17-xCox系列合金具有菱方Th2Zn17型結(jié)構(gòu)；通過(guò)成分微調(diào)使其居里溫度處在室溫附近：Pr2Fe17-xCox，系列合金有較大的磁熵變，在低場(chǎng)下的磁熵變是金屬Gd的65％～73％，而高場(chǎng)下的磁熵變則為金屬Gd的63％～68％；但其成本約為金屬Gd的1／10，具有很高的性價(jià)比，是一類有很大應(yīng)用潛力的室溫磁致冷材料。

Abstract:The calculations of total energy, band structure, electronic density of states and Mulliken population of LaNi5 have been performed by adopting the method of total energy based on the Density Functional Theory. The augmented plane wave function was selected as the basis set in combination with Ultra-soft Pseudopotential technology. The electronic structures of LaNi5 and LaNisH and the change in the formation of LaNisH were analyzed according to the result of total density of states and partial density of states for different orbits. The metal-hydrogen bonding feature was discussed. The stability of the hydrogen interstitial site and the preferred site occupation of the absorbed hydrogen atoms were preliminarily explored.

Abstract:The fracture morphology and microstructure of Uranium-Niobium caused by explosive loading were investigated. The results show that U-Nb is in shear fracture with explosive loading, there are many adiabatic shear bands(ABS) in microstrcture caused by high strain rate. The grains near the ASB have been elongated obviously. The microcracks exist in fragments and spread along the ASB. The fragments form when the cracks meet with the main cracks resulting from the tensile strain on the circumference direction of U-Nb tubes.

Abstract:采用固相反應(yīng)法制備了Li1＋xV3-yMyO8（M=Mo，P：O≤y≤0.4），研究了不同Mo和P含量對(duì)Li1＋xV3-yMyO8相的影響，并首次對(duì)其進(jìn)行了高溫陰極放電性能的研究。結(jié)果表明：Mo和P摻雜量分別為y≤0．2和y〈0．2時(shí)可獲得純Li1＋xV3-yMyO8相：Mo摻雜使Li1＋xV3-yMyO8峰值電壓提高0-3V，比容量提高25％，嵌入的Li^＋量最高可達(dá)x=3．8：P摻雜（y≤0．20）Li1＋xV3-yMyO8的峰值電壓和比容量影響較小?；瘜W(xué)嵌鋰實(shí)驗(yàn)也證實(shí)摻雜后的材料具有更快的Li^＋嵌入速度。

Abstract:Magnesium alloys were treated in a solution containing silicate, fluoride and glycerol at a constant applied current density. The effect of current density on breakdown voltage, ignition time and coating thickness was investigated. SEM was employed to examine the surface morphology of ceramic coatings formed on magnesium alloys at different applied current density, and the corrosion resistance was also measured by EIS. It was concluded that according to the Voltage-Time response, the MAO process is simply divided into gradually increasing stage and a relative stable stage. With the increase of applied current density the cell voltage increasing rate is improved, coating thickness is increased lineally and ignition time is decreased, but the breakdown voltage has no apparent variation. The number of pores is decreased with the increase of current density, but the diameters of the pores are increased; EIS results indicate that corrosion resistance of ceramic coating increase firstly, then decrease with the increase of applied current density.

Abstract:異質(zhì)形核是凝固領(lǐng)域的核心問(wèn)題之一，界面共格對(duì)應(yīng)理論無(wú)法解釋金液滴異質(zhì)形核過(guò)程中ZrC，TiC，TiN等基底的觸媒作用優(yōu)于TiO的現(xiàn)象。利用余氏“固體與分子經(jīng)驗(yàn)電子理論”以及程氏“改進(jìn)的TFD模型中表面電子密度相等的邊界條件”，分析表明界面共格對(duì)應(yīng)并不是有效觸媒基底的本質(zhì)要求：在Tillen靜電作用理論基礎(chǔ)上，建立了Au液凝同異質(zhì)形核價(jià)電予模型與基底觸媒效用判據(jù)，據(jù)此分析了ZrC，TiC，TiN，TiO基底對(duì)Au液滴異質(zhì)形核的觸媒效用，與實(shí)驗(yàn)結(jié)果吻合。

Abstract:建立了超導(dǎo)復(fù)合帶材的細(xì)觀力學(xué)假設(shè)和模型、以及成型過(guò)程的有限元分析模型。模擬了輥軋、平模冷壓成型時(shí)復(fù)合帶材的變形情況以及復(fù)合帶材橫向裂紋、芯絲斷裂及邊部破裂的產(chǎn)生。帶材成型的有限元模擬對(duì)于超導(dǎo)復(fù)合帶材的成型研究具有很好的指導(dǎo)作用。

Abstract:A phase-field approach which incorporates both heat and solute equations for simulation of Al-Cu binary alloy solidification is studied. The dependence of dendritic growth behavior on intentionally varied thermal diffusivity Dris investigated. The calculated results indicate that with the decrease of the thermal diffusivity DT, the influence of the release of latent heat on the original temperature field decreases, the undercoolins in The melt can maintain relatively steady; while the dendritic lip velocity increases, the dendritic morphology presents more developed side-branches, and the solute segregation is small accordingly. The simulation results are compared with those obtained experimentally; they agree well with each other.

Abstract:The effect of pack aluminizing fillers (Al2O3, Y2O3) on the aluminide coatings are studied by changing the traditional pack aluminizing. The phases and the surface morphologies of aluminide coatings before and after oxidation are examined by XRD and SEM. The results show that the pack aluminizing fillers take part in the aluminizing process, which does not only keep the Al power from sintering, but also affect the phases in the aluminide coatings. The aluminide coatings with the pack aluminizing fillers (Al2O3) are mainly composed of Al3Ti + AlTi + AlTi3 phase, but mainly of AlTi3 phase when the pack aluminizing fillers contain Y2O3, which conflicts with the traditional mechanism of pack aluminizing. The pack aluminizing fillers also have much effect on the surface morphologies of aluminide coatings before and after oxidation and the style of Al2O3 crystal lattice.

Abstract:采用共濺射方法存玻璃基片上制備了（FePt）1-xCux合金薄膜，F(xiàn)ePt合金中添加Cu可以有效降低退火溫度，（FePt）1-xCux（x=19．5％）在350℃退火后可以使面內(nèi)矯頑力Hc〃，達(dá)到200kA／m，垂直矯頑力Hc⊥達(dá)到280kA／m左右，而純FePt僅有幾千A／m。X射線衍射結(jié)果表明退火后形成的FePtCu三元合金是降低退火溫度的主要原因。剩磁曲線分析表明Cu的加入不能明顯降低晶粒間交換耦合作用。（FePt）1-xCux在400℃退火可以得到10^-24m^3的磁激活體積。

Abstract:研究了用部分Ca取代LPC（LPC為無(wú)釹鑭鐠鈰混合稀土金屬），同時(shí)用部分Ni取代Mg的（LPCCa）2（MgNi）17合金的吸放氫性能。比較了不同溫度下，不同成分配比對(duì)合金貯氫性能的影響。其中，（LPC）1.9Ca0.1Mg15Ni2合金具有相對(duì)較低的放氫溫度和較大的放氫節(jié)，住275℃的放氫量達(dá)3．43％（質(zhì)量分?jǐn)?shù)）。分析了（LPC）1.9Ca0.1Mg15Ni2的微觀結(jié)構(gòu)，同時(shí)對(duì)合金放氫溫度降低的原岡進(jìn)行了討論。

Abstract:In the text, a commercial software ANSYS was used to simulate hot-push forming technology on TA2 titanium ring pipe Concave edge strain and stress, convex edge strain and stress, flank edge strain and stress even the change of wall thickness during deformation were studied. It is shown that equivalent stress is enlarge with the bending angle in bending deformation; equivalent strain in concave edge is greater than that of convex edge and the value of equivalent strain is enlarge with the bending angle; In the bending deformation, the bending radius is small and the bending deformation is large. As a result, the thickness of concave edge is thickening which received the compress stress and that of convex edge is reducing which received tensile stress. The conclusion of numerical simulation and test are accordant.

Abstract:An investigation was conducted to determine the causes of weld defects in laser Be/Al weldments. In agreement with earlier studies, features on the fracture surfaces consistent with hot shortness cracking were observed. In this paper, conduction mode welds and keyhole mode welds were used to produce specimens. Closer examination of the fusion zone crack regions reveals the cracking is a result of thermal stress, shape of welds root and impurities segregation. The defects type relate to the weld parameters, the cracks nucleate easily at conduction mode weld, and the blowholes appear easily in keyhole mode weld.

Abstract:In this paper, a mechanism of self-propagating high-temperature synthesis of TiC-Ti composite was studied by means of a combustion wave front quenching method in which all information about a process of a phase transitions and a process of a microstructural evolution were remained in the quenched sample. The product was analyzed by X-ray diffraction (XRD), and the process of a microstructural evolution was investigated using scanning electron microscope (SEM) and energy dispersive X-ray (EDX). Based on these experimental results, the mechanism of self-propagating high-temperature synthesis of TiC-Ti cermets was discussed. The experimental results show that the mechanism of SHS of TiC-Ti can be described with a dissolution-precipitation mechanism. The Ti powders melt firstly, and the C particles dissolve in the Ti liquid. C atoms react with Ti and became TiCx. And with the temperature rising, the TiCx particles melt and form Ti-C liquid. As the temperature decreasing, the small TiC particles precipitate from the Ti-C liquid. In the end, a great amount of TiC precipitate from the Ti-C liquid and aggregate. The final products are composed of TiC particles and Ti matrix.

Abstract:The structure and properties of Ti-B-N coatings prepared by radio-frequency plasma-enhanced chemical vapor deposition (rf-PCVD) have been investigated in this work. The coatings were characterized by energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and optical microscopy. Ball-on-disk tribometer and microscopic hardness tester were employed in evaluating the mechanical properties of the coatings. The results show that the structure of the coatings is a nanocomposite, where nanocrystalline TiN is embedded in the amorphous BN and TiB2 matrix. Compared with TiN coatings, the micro-hardness of Ti-B-N coatings can reach 40 GPa. The wear resistances of Ti-B-N coatings remarkably increase with a certain addition of boron, which caused the change of friction mechanism of TiN coatings, although its friction coefficient is higher than that of TiN.

Abstract:Nano-Mo-La2O3 power with the average grain size being about sixty nanometers was prepared by the sol-gel. Mo-La2O3 electrical contact material was fabricated by hot pressure sintering. It is found that the electrical contact material is uniform, La2O3 particles were distributed around the grain boundary or in the crystal, and the average grain size of the particles are mostly less than one hundred nanometer. After breakdown tests, the breakdown points distribute around the whole face, the electron erosion is shallow, and the electron erosion firstly occurred in the La2O3 phase.

Abstract:An ingot of Nb based in-situ composites (NBISC) was produced by a vacuum self-consuming arc melting furnace. The directionally solidified samples were prepared by an electron beam floating zone melting (EBFZM) furnace with a high temperature gradient, and their microstructural characteristics were analyzed. The results show that the microstructure of as-cast NBISC is composed of primary dendrites of Nb solid solution (Nbss) and the eutectic colonies of Nbss plus (Nb,Ti)3Si/(Nb,Ti)5Si 3. In the EBFZM furnace, with the increase of withdrawing rate, the eutectic microstructure of NBISC is refined. The amount of eutectic colonies layers increases. The sizes of (Nb,Ti)3Si/(Nb,Ti)5Si3 lumps or plates decrease and their amount increases. Their morphology tends to more regular, and the distribution becomes more homogeneous. The directionality becomes intensive and the directionally solidified effects are remarkable.

Abstract:采用粉末冶金方法，通過(guò)Ti與Cr3C2反應(yīng)原位生成TiC顆粒增強(qiáng)鈦基復(fù)合材料。利用X射線衍射（XRD）、透射電鏡（TEM）等手段對(duì)其相組成和顯微組織進(jìn)行了研究。結(jié)果表明：通過(guò)Ti與Cr3C2反應(yīng)能夠原位生成TiC顆粒，生成的TiC顆粒呈多角狀，粒度在幾十納米到50μm范圍內(nèi)；Cr3C2中的Cr固溶在Ti基體中，使基體由α＋β兩相合金轉(zhuǎn)變成為亞穩(wěn)態(tài)β型鈦合金。

Abstract:The microstructure of the explosively compacted Nd-Fe-B permanent magnets has been investigated by means of TEM and XRD. It is shown that there are three kinds of phases: matrix Nd2Fe14B, O-rich phases and Nd-rich phase with different structures and compositions in explosively compacted Nd-Fe-B permanent magnets. Matrix Nd2Fe14B is predominantly the hard Nd2Fe14B phase with lattice parameters of a=0.88 nm and c=1.22 nm. The O-rich phase presented at the two-grain boundaries and three-grain junctions, with fcc structures, and lattice parameter is a=0.559 nm. The O-rich phase belong to the compound Nd-Fe-O, and contents of O, Nd and Fe are 56at%, 22at% and 21at%, respectively. It is also shown that a large number of the block-shaped Nd-rich phases are in the two-grain boundary or three-grain junctions or Nd2Fe14B phases, with hcp structure and lattice parameters of a=0.395 nm and c=0.628 nm. The Nd-rich phases belong to compound Nd-O, and contents of Nd and O are 85at% and 12at%, respectively. Also a few dislocations in the boundary phases have been observed.

Abstract:采用X射線符亍射（XRD）、透射電鏡（TEM）研究了球料比為8：1、轉(zhuǎn)速280r／min和球料比為25：1、轉(zhuǎn)速450r／min條件下絳不同球磨時(shí)間后混合粉末的相變、晶粒大小和微觀形貌等。結(jié)果表明：通過(guò)機(jī)械合金化可以制備出Al-15％Pb-4％Si-1％Sn-1．5％Cu納米晶粉未，而且球磨導(dǎo)致了合金粉體非晶化，在球磨過(guò)程中混合粉體首先細(xì)化、合金化和納米晶化，然后部分納米晶轉(zhuǎn)變?yōu)榉蔷?；在機(jī)械合金化過(guò)程中球料比越大、轉(zhuǎn)速越高，即給球磨系統(tǒng)供給的能量越大，則混合粉末獲得納米晶的時(shí)間越短：基于多層非晶化模型討論了△Hmin≈1.34的情況下Al-Pb非晶形成的機(jī)制，指出在機(jī)械合金化過(guò)程中Al-Pb非晶形成并非需要△Hmin〈〈0，其非晶化驅(qū)動(dòng)力主要由濃度梯度提供。

Abstract:Taking the process of producing MIM Ti-6Al-4V alloy by HDH powder as a reference, the processes of making P/M Ti-6Al-4V and MIM Ti-6Al-4V by using TiH2 have been discussed. When using HDH Ti powder making MIM Ti-6Al-4V the tensile strength is 819 MPa and elongation percentage is 7%. When using TiH2 powder making P/M Ti-6Al-4V the tensile strength is over 850 MPa. And when using TiH2 powder making MIM Ti-6Al-4V, processes of dehydrogenation and debinding are successfully reached.

Abstract:The experimcnts of coatirtuous casting and directional solidifing titanium ahoy slabs were performed in a multi-functional electromagnetic casting apparatus with rectangular cold crucible. The influences of process parameters were evaluated on the surface qualities and macrostructures of the casting slabs. It is shown that the surface variations of the slabs get to be well with the increasing of the number of coil turns and the input power. While, it seems to be bad with the increase of the withdrawal velocity and the reduce of the relative position of dummy to the induction coils. The limits of influence of process parameters are deduced as that the first one is the induction coil, the second one is the input power, the third one is the withdrawal velocity, and the last one is the dummy position. With the selective optimized parameters, the slabs free from cracks and ripples are obtained under the experimental conditions. It is interpreted that the variations of meniscus volumes has the significant effects on the casting process, which in turn to be the results of surface qualities of cast slabs. With the increasing of the number of induction coil turns and the decreasing of the withdrawal velocities, the numbers of grains reduced and the grains are parallel to the growth direction. The slabs with both good surface quality and uni-directional macrostructure were cast in cold crucible whose cross section is approximately rectangular.

Abstract:研究了二級(jí)回火工藝對(duì)Nd12.0Dy28Fe747Co34Cu0.2B6.9磁體磁性能和微結(jié)構(gòu)的影響。研究結(jié)果表明：二級(jí)回火對(duì)磁體的剩磁和磁能積影響很小，內(nèi)稟矯頑力Hcj隨二級(jí)回火溫度升高而增大，在480℃時(shí)達(dá)到最大；高于480℃后，風(fēng)隨二級(jí)回火溫度的升高而迅速下降；存480℃二級(jí)回火時(shí)，執(zhí)隨回火時(shí)間的增加而增大，經(jīng)2h回火達(dá)到最大；大于2h后，回火時(shí)間的進(jìn)一步增加對(duì)Hcj影響很小；480℃二級(jí)回火2h時(shí)磁體主相晶粒邊界光滑，富稀土相在晶界分布連續(xù)、均勻。

Abstract:ITO films were prepared by r.f. magnetron sputtering, and were annealed in ammonia, nitrogen and air atmosphere respectively. The annealing effects on electrical and optical properties of ITO films under different atmospheres were studied using X-ray diffraction (XRD), Hall Effect and UV-VIS-NIR spectrometer. The transmission of ITO films is greatly improved by the heat treatments in all atmospheres. The electrical properties of ITO films annealed in ammonia are better than in other two atmospheres.

Abstract:采用靜電白組裝工藝存玻璃襯底上制備了TiO2薄膜，研究其在波長(zhǎng)為254nm和365nm的紫外光及可見(jiàn)光等不同光源照射下殺滅大腸桿菌的性能?？咕鷮?shí)驗(yàn)結(jié)果表明：254nm波長(zhǎng)的紫外光本身具有較強(qiáng)的殺菌作用，不宜在TiO2薄膜光催化殺菌實(shí)驗(yàn)中作為實(shí)驗(yàn)光源；在365nm波長(zhǎng)的紫外光激發(fā)下，靜電自組裝TiO2薄膜有較好的殺菌效果，365nm紫外光本身對(duì)細(xì)菌的殺滅作用較弱；靜電自組裝制得的TiO2薄膜經(jīng)可見(jiàn)光光源（光強(qiáng)81．7μW／cm^2）照射8h后，對(duì)大腸桿菌的殺菌率可達(dá)91．1％。

Abstract:Using the double glow plasma metallulgy principle improve the tribological properties of Ti6Al4V. A high pure solid honeycomb graphite was taken as source cathode, titanium alloy Ti6Al4V as cathode, high pure argon and nitrogen gas as working gas, The carbonitriding Iayer with special physical and chemical properties was prepared on the surface of Ti6Al4V. The phase compositions and C. N, Ti distribution in carbonitriding layer were determined by means of XRD and glow discharge spectrometry. The surface layer microhardness distribution was measured gradually from surface to inner. Microhardness of surface increased more than two times. Results from friction and wear test show thai the wear resistance property of TifAl4V alloy is improved evidently.

Abstract:為探索適于中溫條件下使用的固體氧化物燃料電池的陰極材料,用甘氨酸-硝酸鹽法(GNP法)制備了Gd0.8Sr0.2CoO3(GSC)陰極粉體,用X-ray衍射考察了GSC的成相溫度.采用絲網(wǎng)印刷法將GSC沉積在(Sm2O3)0.2(CeO2)0.8(SDC)圓片上,制成對(duì)稱陰極,在不同溫度下燒結(jié).用交流阻抗譜從500℃到750℃測(cè)量了GSC陰極和SDC電解質(zhì)之間的界面電阻.結(jié)果表明,用甘氨酸-硝酸鹽法制備的GSC粉體的成相溫度比傳統(tǒng)固相法降低了400℃～500℃;700℃時(shí),GSC陰極的界面電阻僅為0.26 Ω·cm2.

Abstract:According to the purity requirement for Si powder, a cold plasma reaction chamber with long drop distance and high reaction rate is provided in the paper. In the selection of technology parameter, we put stress on increasing the thickness of sheath, raising the densities of reaction particles, and controlling the speed of pump. The purifying rate, collective ratio, and drop time of Si powder were raised effectively as a consequence of these selections. The experimental results show that solar grade Si (4N) can be gotten from industrial Si (Melatturgical grade Si-2N) in the plasma system.

Abstract:The ternary metal silicide Co3Mo2Si is expected to be a promising wear resistant material due to its inherent high hardness, strong anomalous hardness-temperature dependence and covalent-dominated strong atomic bonds. Poor ductility from room to intermediate high temperatures is currently the main obstacle preventing it from practical industrial applications. In order to improve the ductility of Co3Mo2Si ternary metal silicide, Co solid solution toughened Co3Mo2Si ternary metal silicide alloys were designed and fabricated by the laser melting/deposition process. As-solidification microstructure of the Co/Co3Mo2Si metal silicide alloys was characterized by optical microscopy (OM), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and Vickers microhardness measurement as a function of Co content. The Co/Co3Mo2Si ternary metal silicide alloys have a dense and uniform microstructure consisting of the Co3Mo2Si primary dendrites and the interdendritic Co/Co3Mo2Si eutectics. Volume fraction of Co3Mo2Si primary dendrites (72%~92%) and the average hardness (8000 MPa~11 000 MPa) of the alloys decrease with the increase of Co content. Compared with the single-phase Co3Mo2Si ternary metal silicide, the Co toughened Co3Mo2Si alloys have excellent balance of strength and ductility, which was attributed to the effective toughening of ductile cobalt solid solution.

Abstract:采用DTA研究了噴霧干燥-H2還原法制備的納米級(jí)90W-7Ni-3Fe復(fù)合粉末隨溫度升高時(shí)熔點(diǎn)和相的變化，依此為根據(jù)研究了試樣存不同燒結(jié)溫度和小同燒結(jié)時(shí)間下的燒結(jié)特性。采用掃描電子顯微鏡和金相儀分別對(duì)試樣斷口進(jìn)行了形貌觀察和W晶粒測(cè)試，并對(duì)燒結(jié)樣的性能進(jìn)行了測(cè)定與分析。研究結(jié)果表明：保溫時(shí)間為120min時(shí)，隨著燒結(jié)溫度的提高，試樣的性能有了顯著的變化，當(dāng)燒結(jié)溫度為1390℃時(shí)，試樣的抗拉強(qiáng)度、延伸率和相對(duì)密度都達(dá)到一個(gè)極大值，分別為888.3MPa，12．9％和99．0％：當(dāng)燒結(jié)溫度為1390℃時(shí)，隨燒結(jié)時(shí)間的延長(zhǎng)，試樣的性能也有顯著的變化，試樣的抗拉強(qiáng)度、延伸牢和相對(duì)密度存保溫120min時(shí)都達(dá)到一個(gè)極大值：平均W晶粒度為20um，W晶粒呈球形或近球形；復(fù)合粉末燒結(jié)活性高，比傳統(tǒng)燒結(jié)溫度降低80℃；粉末中高的氧含量和在干氫中的燒結(jié)，使得試樣在液相燒結(jié)時(shí)容易出現(xiàn)孔洞和氣泡，W晶粒和粘結(jié)相分布不均勻，致使試樣力學(xué)性能偏低。

Abstract:A new silver-rare earth oxide contact material, Ag/SnO2-La2O3-Bi2O3, has been produced using powder metallurgy method. The microstructure of Ag/SnO2-La2O3-Bi2O3 was analyzed using SEM and EDS. The new contact material was tested through temperature rise, make-break capacity testing and arc erosion. The new contact material passes the make-break capacity testing, its temperature rise is similar to that of Ag/CdO and the average arc erosion of make contact is only 2/3 that of Ag/CdO. At last, the cost of Ag/SnO2-La2O3-Bi2O3 and Ag/CdO is analyzed. From the testing results and the cost analysis, the new material has preferable physics, mechanism and electric behavior and lower cost. The new innocuity contact material may be substituted for Ag/CdO because of its preferable application foreground and economy benefit.

Abstract:以乙醇為分散劑和保護(hù)劑，采用反向化學(xué)共沉淀法，制備了Y2O3-ZrO2納米晶。結(jié)果表明：所制備的納米晶為說(shuō)辦晶系；Y2O3-ZrO2納米晶呈球形，當(dāng)焙燒溫度為900℃時(shí)，粒予粒徑約30nm，粒徑分布均勻，無(wú)明顯硬團(tuán)聚體存在；Y2O3-ZrO2納米晶為多晶結(jié)構(gòu)：Y2O3-ZrO2的晶化溫度為489．19℃；Y2O3-ZrO2納米晶的相對(duì)密度隨粒徑增大而增大。

Abstract:采用改進(jìn)水熱法（金屬Ti片與等濃度的Ba^2＋，Sr^2＋強(qiáng)堿性溶液于250℃水熱反應(yīng)5h，然后經(jīng)過(guò)600℃，0．5h燒結(jié)處理）制備了單一立方相的Ba0．5Sr0．5TiO3薄膜。制備的Ba0．5Sr0．5TiO3薄膜通過(guò)XRD，SEM和XPS進(jìn)行表征分析。結(jié)果表明：600℃下經(jīng)過(guò)0．5h燒繪處理的Ba0．5Sr0．5TiO3薄膜結(jié)晶更完整：同時(shí)，制備的Ba0．5Sr0．5TiO3薄膜表面吸附有OH，經(jīng)過(guò)10min刻蝕處理后，吸附的OH能譜峰消失。

Abstract:The metal flowing behavior in welding zone of FS welds has great influence on the welds mechanical performance. The friction stir welding (FSW) of 5 mm thickness plates of 1060 Al/3003 Al was carried out. The flow of metal during FSW was investigated by etching of the nugget in the welding zone of the 1060 Al/3003 Al. The flow visualization was examined in the range of welding parameters. The transverse and horizontal cross section was analyzed. The result shows that the process parameters influence the metal flow visualization greatly. With a high tool rotational speed and a proper welding speed, a steady and well-welded join can be produced.