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Abstract:綜述了粉末冶金鈦合金致密化工藝及致密化機(jī)理研究的新進(jìn)展。粉末冶金鈦合金致密化工藝除采用傳統(tǒng)的熱等靜壓工藝外，注射成型、激光成型等新技術(shù)的應(yīng)用可以得到相對密度達(dá)99％的燒結(jié)件，其拉伸性能達(dá)到甚至超過熔鍛鈦合金的水平；致密化理論方面的研究除擴(kuò)散、蠕變及屈服機(jī)制外，鈦合金中還有相變致密化機(jī)制與多組元合金元素的強(qiáng)化致密化機(jī)制。其中當(dāng)粉末鈦合金在理／口兩相區(qū)溫度下進(jìn)行循環(huán)熱壓時，相變致密化起主要作用。當(dāng)多組元粉末鈦合金燒結(jié)時，促進(jìn)液相形成或提供擴(kuò)散通道的合金元素起強(qiáng)化致密化作用。這兩種致密化機(jī)制在粉末鈦合金燒結(jié)的實(shí)際應(yīng)用中有重要意義。

Abstract:The main types,met ho ds of productio n,and failure modes for high-temperature protective coatings a re briefly considered.The paper emphasizes the importance of alumin ide coating s for high-temperature p rotection and of studies of high-tem perature oxidati on of the high-temperature coatings in general.

Abstract:Numerical simulation of pulsed magn etic flux density and L orentz force i n the solidifying sample inside a str aight solenoid coil during the solidification under tra nsient pulsed magnetic field was stu died using ANS YS5.5software.The simulation showed that both the axial and radial distribut ions of th e pulsed magnetic flux density and th e Lorentz force,during the sol idifi cation under pulsed magnetic field,were not only asymmetrical but also n onuniform.The simulation method is generally useful for studying solid ificatio n behaviors and structures during solidification under transient pulsed magnetic field.

Abstract:In the implantation of lithium ions i nto a nd dissipation from lithium/me taloxide Positive material,the voltage and sta bility of the material can be analyzed and predicted using the first principle m ethods.This paper reviews the theoretical background of first principle methods and presents the results of a recent study of LiCoO 2 positive electrode.The investigation of Li x NiO 2 and multi-element substitution should be a focal point of future rese arch .

Abstract:In this paper,an ideal liquid model of s ym metrically colliding was taken to analyze the distribution character of natural strain field.The results show that the strain at stagnation point is infinite, and stra in saltaion is completed in fivefold jet thickness at explosive welding interface.

Abstract:用示差掃描熱分析儀(DSC)、X射線衍射儀(XRD)和光學(xué)顯微鏡系統(tǒng)研究了熱處理和熱循環(huán)對Ru-49Ta高溫形狀記憶合金馬氏體相變行為的影響。結(jié)果表明：Ru-49T8合金的Ms(馬氏體相變開始溫度)和Af(馬氏體逆相變結(jié)束溫度)分別為1065℃和1085℃，相變溫度范圍(Ms-Mf)為15℃，相變熱滯和相變熱比較小，分別為22℃和2J／g。熱處理對Ru-49Ta合金馬氏體相變行為影響不大，該合金的馬氏體相穩(wěn)定性良好，不存在時效效應(yīng)，相變方式為孿生。熱循環(huán)對Ru-49Ta合金馬氏體相變溫度和熱滯影響不大，隨熱循環(huán)的進(jìn)行，相變熱有所減少。

Abstract:采用磁控濺射方法在p-Si(111)襯底上淀積5nmPt膜，分別在350℃-600℃退火。原子力顯微鏡(AFM)觀察和x射線光電子譜(XPS)分析表明，隨退火溫度的增加，平坦的薄膜表面變得粗糙，其相分布由Pt-Pt2Si-Ptsi變?yōu)镻t Pt2Si PtSi-Ptsi。

Abstract:The influence of the phase assemblag e of precursor powder on microstructures and the properties of Bi (Pb)-2223/Ag tapes has been studied.The phase assemblage was controlled by changing the final c alcination temperature.The r esult s show that a precursor powder containing mainly the Bi (Pb)-2212ph ase and some other second phases which include(Sr,Ca )CuO and Ca 2 PbO 4 phase,and without any2201and 2223phases is considered a g ood choic e for the fabrication of hig h J c Bi (Pb)-2223/Ag tapes.Accordingly,calcination of the precursor pow der just below the form ation temperature of 2223phase is th e most favorabl e.A maximum critical current density of 12kA/cm 2 was obtained.

Abstract:Th e Nanometer TiO 2 powder was put into the unsaturated p olyester resin for the simultaneous mo dification of strength-ening and flexibilizing.The impact strength was used to characterize th e ductility of the nano-TiO 2/UPR.It was found that the resin had the apparent brittleness-ductility t ransition phenomenon,a nd the content of TiO 2 at the brittleness-ductility transition point,was 6wt%.The bending stre ngth and impact strength of the nano-TiO 2/UPR were increased by 55%and 46%respectively compared with those of UPR.The micro observation of the impact fracture i ndicaties that,the fracture pattern of the nano-TiO 2/UPR changes from typical brittleness to typical toughness fracture near th e critical point.

Abstract:The effects of an electric field appl ied du ring solution treatment on the precipitation kinetics in Al-Li all oy 2090h ave been studied using differential scanning calorimetry(DSC).It is found tha t electric field decreases the peak temperatures of?' and T 1 phases precipitation,bringing their curves forward.It le ssens the enthalp y of T 1 precipitation,while keeping that of?' precipitation unchanged.At the sa m e time,the electric field increases the rates of?' and T 1 precipitation in the first stages,while decreases those in the last stages .An electric field also reduces the activation energies of?' and T 1 phases precipitations.It is though t that the electric field increases t he concentration of vacancies and the hence solubility of alloying elements,there by decreasing the activation energies of these two precipitation mechanisms.

Abstract:考察了不同成分的Ti-Fe-Mo-Mn-Nb-Zr合金的壓縮強(qiáng)度、硬度，得到了高壓縮強(qiáng)度，硬度與牙本質(zhì)相近的鈦合金。在綜合考慮鈦合金成本、力學(xué)性能的基礎(chǔ)上，采用模糊推理系統(tǒng)建立了鈦合金中的元素質(zhì)量百分含量與硬度之間的關(guān)系，并通過實(shí)驗(yàn)法進(jìn)行了驗(yàn)證，預(yù)測結(jié)果與實(shí)際測定結(jié)果的對比是令人滿意的。在保證性能的基礎(chǔ)上，利用訓(xùn)練好的模糊推理系統(tǒng)對材料的成分進(jìn)行優(yōu)化，減少貴重元素的加入量。

Abstract:The abnormal blu e oxide films occurred at the heat-affected zone of zircalloy-4cladding tube af ter electron beam welding,were studied using XPS,EDX,TEM.The resu lts indica te that iron and tin in the a bnormal oxide film exist in the form o f Fe 2 O 3 ,SnO 2 ,and the ratio of Fe to Sn in abnormal blue oxid e film is higher than that of the norma l one.These results will provide the basis of the further researc h.

Abstract:The effect of Sc on microstructure an d tensile p roperties of Al-Li-Cu-Mg-Ag-Zr alloy has been studied using o ptical and t ransmission electron microscopy and scanning electron microscopy.The results sh ow that addition of Sc may refine the gra in size,and encourages the homogeneou s precipitation of T 1 phase throughout the matrix,The wid espread precipitation of T 1 phase promotes homogeneous deforma tion thereby improving the mechanical pr operties of these trace-Sc containi ng.

Abstract:The cavitat io n erosion of TiNiNb alloy and 0Cr13Ni5Mo stainless steel wa s investigated u sing rotating disc e quipment.To simulate the effect of the collapse of vapor c a vities or bubbles,a Rockwell hardness tester was used to exert a load on th e surface areas of the alloys.The results show that the cavitation ero sion resi stance of TiNiNb is greater than that of 0Cr13Ni5Mo.The TiNiNb a lloy is mo re elastic than0Cr13Ni5Mo stainless steel in the in dentation test,thereby permitting TiNiNb to absorb and relieve more imp act energy during cavitation er osion.This reduces volume loss,a nd leads to excellent cavitations erosion res istance.

Abstract:采用低溫強(qiáng)堿法制備了粒徑為40nm左右的高純納米四方多晶氧化鋯粉體。對于納米四方多晶氧化鋯粉體在不同條件下的Zeta電位的測試表明，聚電解質(zhì)分散劑聚丙烯酸銨(NH4PAA)使粉體等電點(diǎn)降低，對聚電解質(zhì)分散劑聚丙烯酸銨在納米四方多晶氧化鋯粉體上的等溫吸附研究發(fā)現(xiàn)，由于聚電解質(zhì)分散劑的作用，懸浮體中納米氧化鋯粉體顆粒表面的電動特性發(fā)生了顯著的變化，其等電點(diǎn)向pH值降低的方向移動了3．5。分散劑用量為1．0％(對于粉體，按質(zhì)量)時，懸浮體穩(wěn)定性較好，該納米粉體漿料的流變特性得到明顯的改善。

Abstract:研究了超細(xì)不銹鋼纖維的制備工藝和產(chǎn)品性能，結(jié)果表明：集束拉拔法能夠制備超細(xì)不銹鋼纖維，但由于加工過程的不均勻變形導(dǎo)致纖維絲呈不規(guī)則圓形。在相同的真應(yīng)變條件下，12μm，8μm和6μm纖維的單絲斷裂強(qiáng)力隨真應(yīng)變的增加而增加，抗拉強(qiáng)度隨著纖維絲徑的減小而顯著增加，在12μm處達(dá)到極大值后又隨著纖維絲徑的減小而顯著降低。3種規(guī)格的纖維表面都存在顆粒狀的碳化物，碳化物在拉伸過程中隨著纖維的減徑而被帶到表面或近表面處，它不僅使纖維芯絲嚴(yán)重不均勻，還會導(dǎo)致纖維沿顆粒處損壞至斷裂，這也是8μm和6μm纖維抗拉強(qiáng)度相對低的原因。

Abstract:Nanostructured W-La 2 O 3 composite powder was prepared by the high energy ball milling,or mechani ca l alloying(MA).Serially W-La 2 O 3 electrode materials were fabricate d by hot pressed sintering in vacuum .In each case the nanostructural evolutions was observed as function of milling tim e and sintering temperature using SEM,XRD and TEM.The results show that the si ntering densification depends on nanosize particle rearrangement ra sther than c onventional diffusion.The enhanced sinterability of MA W-L a 2 O 3 composite powder is attributed to their ultra-fine and homogeneously mixed state,high internal strain,as well as the sintering activation by impurity ele ments.

Abstract:Three types of thermal barrier coatin gs (TBCs )were prepared by plasma spray(PS)on GH536superalloy substrate with d ifferent layers.One is the traditional TBC wi th Ni22Cr10AlY as bond co at and ZrO 2-8wt%Y 2 O 3 (8YSZ)as top coat,the other two TBCs have a t riplex structure with comp osite layers of 8YSZ +Al 2 O 3 and ZrO 2 ,respectively.The static oxidatio n test and thermal shock tests were cond ucted to evaluate the oxidation kinetics and thermal shock cyclic lifetime of th e TBCs.With the different failure criterions,the failure mechanism of TBCs was discussed.The thermal shoc k resistance of state-of-the-art duplex TBCs is the best.It is indicated that the higher oxidation resis-tance is obtained by using of composite 8YSZ +Al 2 O 3 ceramic layer.It has the better oxid ation resistance if using 8YSZ +Al 2 O 3 as the inner composite layer of TBCs,comparing with as the out layer.

Abstract:以SnCl4^ 5H2O和SbCl3為原料，通過正交實(shí)驗(yàn)并借助于XRD，TEM等手段，研究了前驅(qū)物濃度、反應(yīng)溫度、保溫時間和氨水滴加速率等工藝因素對水熱合成銻摻雜SnO2納米粉體的影響，探討了不同分散處理工藝對納米粉體分散性的影響。

Abstract:The influence of milling rate in range from 125r/min to 225r/min and the ad dition of from 0%to 4. 5%of the process control agents ethanol,stearic acid on the mechanical alloyi ng of a Ti-Cr alloy h as been investigated.The results sh ow that the higher t he milling rate,the smaller the powders as other milling conditions are unchang ed.Ethanol as a useful process control a gent lowes the impurity level during M A processing,but results in reduced fining efficiency.The reco mended addition of ethanol is under 1.5%.The abrasion of either milling balls or milling j ar can be controlled by optimizing the milling r ate and selection the best proc ess co ntrol agent.

Abstract:Experimentally determined AC loss i n Bi2223tapes at 4.2K under applied D C magnetic field is discussed.Considered are the influences on the seif-field loss of:(1)The applied DC field(2).The resistivity of the sheath materia l.(3)The critical current and the number of superconducting filaments.All o f the experiments are performed at 4.2K and at appled magnetic fields of up to 5T.