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Abstract:The criteria for stability of eutectics,solid solutions and precipitates are proposed.It is based on the Thomas-Fermi-Dirac model on the boundary conditions that electr on densities and chemical potentials should be equal in either side of a co mposite film.The optimum condition for stabilizing the energ y balance and the sizes of eutectics o r precipitates is given.

Abstract:美國高新技術(shù)研究所(HTR)采用連續(xù)裝管成型(CTFF)粉末裝管技術(shù)(PIT)制備了MgB2/Fe復合線。目前已制備出直徑為1.2mm的先驅(qū)線(包Fe的Mg+B混合粉),長度達70m。在800℃～950℃處理3min～30min的短樣品,傳輸臨界電流密度(Jc)在4K/4T下達到(2～3)×104A/cm2,在4K/2T下達到4×104A/cm2,在4K自場下外推的Jc最少達到2×105A/cm2。用磁測量方法得到的Jc與外推得到的傳輸臨界電流值差不多。

Abstract:運用量子化學計算理論，求出了有關(guān)化合物的熱化學參數(shù)，并根據(jù)有關(guān)熱力學模型，計算了金屬間化合物Ti2AlNb中元素的活度，由此計算了SCS－6 SiC長纖維增強Ti2AlNb金屬間化合物復合材料界面反應的Gibbs函數(shù)變值△rG,用△rG判據(jù)推測了界面反應產(chǎn)物并與透射電鏡實驗結(jié)果進行了對比分析。研究表明，由于Ti2AlNb中原子結(jié)合力較Ti3Al強，因而SCS－6 SiC/Ti2AlNb復合材料的界面反應較SCS－6 SiC/Ti3Al輕。反應初期形成晶粒非常細上的TiC,Ti5Si3,晶粒較大的TiC和Ti3Si是由于元素擴散和反應所形成。在對復合材料的熱暴露中，這些反應產(chǎn)物均進一步長大，并由于反應Ti3Al C→Ti3AlC，在Ti2AlNb基體中形成一些三元反應產(chǎn)物Ti3AlC晶粒。

Abstract:通過對Ag元素摻雜的贗兩元合金（PbTe)1-x(SnTe)x(0≤x≤0.4）熱電性能進行研究發(fā)展，處于本征態(tài)的PbTe合金電導率對摻雜較為敏感。但當摩爾分數(shù)增大時，贗兩元合金（PbTe)1-x(SnTe)x電導率隨摻雜量的增大受到抑制，這在高溫情況下尤為顯著。當溫度低于約423K時，摻雜量對PbTe合金的Seebeck系數(shù)影響不大；但當溫度大于423K時，PbTe合金的Seebeck系數(shù)隨摻雜量而增大。摻雜量越大，摩爾分數(shù)越高，同一合金的Seebeck系數(shù)變化越小。熱電優(yōu)值計算表明，摻雜0.02mol%的合金系較適宜于制作成分遞變的熱電材料（FGM）。

Abstract:利用雙剪切蠕變試樣在受剪切區(qū)的筏化試驗結(jié)果和不同晶體取向試樣的蠕變持久壽命試驗結(jié)果，對鎳基單晶合金的蠕變筏化預測模型和蠕變持久壽命模型進行考核，證實此2個模型的合理性。

Abstract:采用單輥旋鑄技術(shù)制備Al-2.5Ti-2.5Fe,Al2.5Ti-2.5Fe-2.5V和Al-2.5Ti-2.5Fe-2.5Cr(at%，下同）合金薄帶，利用X射線衍射（XRD）和透射電鏡（TEM）分析了這些合金的急冷態(tài)和退火態(tài)組織。結(jié)果表明：快速凝固Al-2.5Ti-2.5Fe合金急冷態(tài)組織中存在Al3Ti和Al5Ti2兩種初生相，快凝合金經(jīng)400℃退火10h后，組織中出現(xiàn)了Al13Fe4相，在450℃退火，組織中析出了彌散Al3Ti相；快速凝固Al-2.5Ti-2.5Fe-2.5V合金急冷態(tài)組織中存在Al11V相和Al80V20相，400℃退火10h后，初生Al11V相轉(zhuǎn)變?yōu)锳l80V20相，且固溶在α-Al基體中的Ti,Fe以Al23Ti9相和Al13Fe4相的形式析出；快速凝固Al-2.5Ti-2.5Fe-2.5Cr合金急冷態(tài)組織中存在Al3Ti和Al13Cr2兩種初生相，快凝合金經(jīng)300℃退火10h后，組織中析出了Al13Cr2和Al3Ti兩種彌散相，400℃退火10h時后組織中出現(xiàn)了Al13Fe4相。

Abstract:Normal penetration of tungsten allo y shells into steel targets was perfo rmed and the total deformation and fr acture history of the shells were successfully obtained.The mic rostructure of received shells was e xamined and analyzed,revealing that the formation of adiabatic shear band at critical section is the mainl y failure behavior of tungsten alloy shell,and matrix rupture at the tip o f internal hollow also results in the damage of the shell.Furthermore,th e failure process of critical sectio n is divided into three steps,i.e.th e formation of adiabatic shear bands,the appearance of micro-cracks in the bands and the expansion of sh ear cracks.In additional,the failu res of tungsten alloy shells start at geometrical stress concentratio n zone in the all received shells,so o nly if the local stress concentratio n coefficients are markedly decreased by shell geometrical design,the tungsten alloy shells can be able to play an important role in several applications,including military engi-neering.

Abstract:The rare earth films with switchable optical properties were found recen tly.During the hydrogen absorption/desorption procedure or electrochemical charging /discharging,the optical properties of the r are earth hydrides can be changed dra stically.In this paper,the crystal structure and thermodynamic properties of rare earth hydrides were intr oduced,the progress in the switchab le optical properties of rare earth hydride films was briefly reviewed.The mechanism for rare earth hydrides with switchable optical propertie s was discussed as well.

Abstract:采用將Li2CO3,電解二氧化錳(EMD)和Co(NO3)2·6H2O混合進行高溫固熔反應的合成方法,制備了1種尖晶石型金屬氧化物催化材料LiMn2-xCoxO4。通過電化學測試(極化曲線、放電曲線)、X射線衍射分析(XRD)以及掃描電鏡(SEM)等方法對電極的微觀結(jié)構(gòu)和性能進行了研究。實驗結(jié)果表明,以LiMn1.95Co0.05O4為催化材料的氣體擴散電極具有最好的綜合電化學性能。其0.9V極化電位時的最大電流密度可達210mA/cm2AA型(5號)樣品電池以100mA電流恒流放電,容量可高達4439mAh。

Abstract:采用掃描電鏡（SEM）、顯微硬度分析、Ｘ－ray衍射和差熱分析（ＤＴＡ）技術(shù)研究了Ｔi-46at%Al混合粉末機械合金化過程中的顯微組織演變。結(jié)果表明：隨著球磨過程的進行，Ｔi-46at%Al顆粒逐漸等軸化，粒度變小，粒度分布變窄；顯微硬度增大，硬度分布和顆粒內(nèi)成分逐漸均勻。經(jīng)過６０h高能球磨，Ａl元素完全固溶入Ｔi晶格內(nèi)，形成納米Ｔi（Ａl）過飽和固溶體，同時，有非晶相形成；球磨至１００h，形成完全非晶相。非晶相的形成是界面處非平衡擴散的結(jié)果，在Ｔi-46at%Al合金中，機械合金化致非晶的晶粒條件是：晶粒尺寸≤１５nm。

Abstract:用薄試樣push-out和push-back試驗測試了SCS－6／Timetal 834復合材料從室溫到530℃溫度范圍內(nèi)的峰值載荷和滑動摩擦切應力。用軸對稱圓柱有限元模型模擬計算了SiC纖維增強鈦基復合材料不同溫度下的界面應力沿軸向分布規(guī)律和界面脫粘過程。計算表明，push-out試驗的界面脫粘過程可以用剪切強度準則描述，對于SCS－6／Timetal834復合材料。當界面單元尺寸L＝6.25μm時，其室溫下界面剪切強度τm=500MPa,300℃時τm＝300MPa，530℃時τm＝140MPa。由于應力奇異性的影響，界面剪切強度的值與單元尺寸大小有關(guān)。

Abstract:The stainless steel fiber manufactu red by bundle drawing method has not o nly the high thermal resistance and c orrosion resistance,but also the flexility and weavable p roperties of textile fiber.It has been used widely as raw material for non woven fabrics and mixture fabrics.Through comparing the physical prop erties of stainless steel fiber with that of traditional woven fiber,it was regarded that stainless steel fib er and traditional textile fabric differ in density,elongation percentag e,rebound resilience,bending resistance,curliness and skin friction co-efficient ,which affect the quality of nonwoven fabrics woven by stainless steel fib er.So it' s important to investigate the properties of stainless steel fiber.

Abstract:AlN piezoelectric film has a lot of excellent physical chemistry properties.This discussion focus on the str uctural characters,pre-pared methods and applied prospect o f AlN piezoelectric films.

Abstract:Unreinforced 6066aluminium alloy a nd the alloy reinforced by SiC partic ulate with various volume fraction were fabricated by spray atomization and co -deposition,and also the unreinforced alloy was fabr icated by as -melten as a contrast,an d the materials were then extruded.It was observed that the aging respon ses of 6066Al and 6066Al /SiCp fabric ated by spray atomization and co -dep osition were accelerated.Metal-lography and transmission electron microscopy(TEM)were utilized to inspect the microstructures of the materials.The effect of processing route and the increased dislocation density resulted from the addition of SiC p articulate into metal matrix on the a ging behavior of the materials was di s-cussed.It is shown that the concentr ation of solute atomand kinetics of phase transformation in materials fa bricated by spray atomization and co-deposition are much higher than the o thers in this paper.Moreover,the decrease in grain size induced by spray atomization and co -deposition and the increased dislocation density in composites resulted from the ad dition of SiC particulates lead to su fficient positions for inhomogeneo ns nucleation and thus accelerate the k inetics of aging precipitation of th e materials involved in this study.

Abstract:利用高能球磨制備了含納米晶Mg2Ni的Mg-Ni貯氫合金，并對其進行了吸氫反應研究。結(jié)果表明納米晶Mg2Ni Mg Ni復相貯氫合金在100℃-150℃可和流動的氫氣反應，證明了納米晶的Mg2Ni不但自身具有很高的反應活性，而且對納米晶的Mg也有較好的催化作用。

Abstract:The wear behavior of as cast and hot ex truded Al-Si-Pb alloys was investig ated under dry condition.The results show that the microstructure and mechanical prop erties can be greatly improved and porosity can be decreased significant ly by hot extrusion.These factors increase wear resistance of hot extr uded Al-Si-Pb obviously.Optical ob servation and X-ray photoelectron s pectroscopy(XPS)analysis reveal that the almost constant wear rate at mediate load level and better resistance to seizure for Al-Si-Pb alloys with more than 15%lead are due to a film of lubricant covered almost entire worn surface in the wear.This film is a mixture containing Al,Fe,S i,O and Pb.

Abstract:采用壓縮的方法對Ti75合金超塑變形時力學行為和組織演變進行了研究。結(jié)果表明,在800℃,5×10-4s-1以及850℃,1×10-1s-1的條件下,m值大于0.3,而900℃時,m值降低;在超塑變形初期由于動態(tài)再結(jié)晶和β相的擴散,實現(xiàn)板條組織的等軸化、細晶化、均勻化,使α晶粒得以進行滑動和轉(zhuǎn)動,晶界運動成為主要變形機制;晶間β相對α晶粒的轉(zhuǎn)動和滑動起著調(diào)節(jié)作用;而位錯運動既是變形機制,又是晶界滑動的調(diào)節(jié)機制。

Abstract:通過大量實驗，對不同Sr/Ba比制作的SBBT高壓陶瓷電容器的擊穿特性進行了研究，指出瓷體中的局部還原現(xiàn)象是造成電容器瓷片擊穿場強嚴重下降的原因所在。經(jīng)過理論分析，提出施主離子Bi^3 在固溶體中的不均勻分布導致瓷體還原的新觀點。在此基礎(chǔ)上，通過加入受主離子Mg^2 克服了還原現(xiàn)象，使電容器的擊穿場強大幅度提高。