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Abstract:The recent developments of additive effect of high-temperature oxide YBCO superconductors were reviewed. The critical current density and transition temperature were improved by chemical addition. The additive can improve the mechanical property and affect precursory powder thermal behavior of YBCO. The research of additive effect can improve applied properties of YBCO .and supply more informations for exploring mechanism of superconductors.

Abstract:To forecast the properties of the HfC1-xNx solid solutions, their valence electron structures were analyzed and compared with those of the HfC and HfN matrix on the base of the empirical electron theory (EET) of solids and molecules. The results showed that, when the HfC and HfN dissolved each other, the step numbers of two nonmetallic atoms (C and N) were invariable, and the step number of Hf element increased form B11 to B16. With the x value increasing, the covalent electron amount and the bond energy on the strongest bond and the melting point, all dropped gradually, while the percentage of total covalent bond number increased, indicating that the hardness, bond energy, melting point and toughness decreased, and the strength increased.

Abstract:The multi-phase field model of Nestler is used to simulate the free growth of isothermal binary eutectic and to study the growth mechanisms under different initial nucleation conditions, including the given quantity and morphology of nucleus and the stochastic nucleation. The variety of Avrami exponent calculated through the relationship between solid volume fraction and transition time demonstrates that there are three possible eutectic growth mechanisms, i.e. the diffusion limited growth, the lamellar growth and the spinodal decomposition growth. And the process of free eutectic growth is the transition process of the three growth mechanisms from one to another.

Abstract:Plastic deformation of bulk metallic glass (BMG) Zr55Al10Ni5Cu30 was investigated by nanoindentation experiments at room temperature. The characters of plastic deformation were studied by means of scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results indicate that the discrete shear bands are formed around the indent and the local free volume is increased in the bulk metallic glass by deformation. The mechanism governing the plastic deformation was discussed in terms of the free volume mode.

Abstract:采用動(dòng)態(tài)蒙特卡羅（kinetic Monte Carlo，簡(jiǎn)稱(chēng)KMC）方法研究物理氣相沉積（physical vapor deposition，簡(jiǎn)稱(chēng)PVD）制備N(xiāo)i薄膜過(guò)程中入射角度對(duì)薄膜微觀結(jié)構(gòu)的影響。該KMC模型中既包括入射原子與表面之間的碰撞，又包括被吸附原子的擴(kuò)散。模擬中用動(dòng)量機(jī)制確定被吸附原子在表面上的初始構(gòu)型，用分子穩(wěn)態(tài)（molecular statics，簡(jiǎn)稱(chēng)MS）計(jì)算方法計(jì)算擴(kuò)散模型中躍遷原子的激活能。對(duì)于模擬結(jié)果，采用表面粗糙度和堆積密度作為沉積構(gòu)型評(píng)價(jià)指標(biāo)。研究結(jié)果表明：當(dāng)沉積速率是5μm／min，基板溫度是300K和500K時(shí)，表面粗糙度和堆積密度曲線(xiàn)在入射角度等于35°時(shí)出現(xiàn)拐點(diǎn)；入射角度小于35°時(shí)，入射角度增大對(duì)表面粗糙度增加和堆積密度減小的影響很少；但是入射角度大于35°時(shí)，隨入射角度增大表面粗糙度迅速增加、堆積密度迅速減小。另外，當(dāng)基板溫度是300K時(shí)，入射角度對(duì)薄膜微觀結(jié)構(gòu)的影響程度大于基板溫度為500K時(shí)的影響程度。說(shuō)明高基板溫度促使原子更加充分地?cái)U(kuò)散，從而能削弱自陰影效應(yīng)的作用。但是，在保證足夠高基板溫度和合理沉積速率的情況下，入射角度過(guò)大同樣不利于致密結(jié)構(gòu)形成。

Abstract:采用氣態(tài)源分子束外延（GSMBE）技術(shù)優(yōu)化生長(zhǎng)了GaAs／AlAs分布布拉格反射鏡（DBR）材料，并用X射線(xiàn)衍射（XRD）及反射光譜對(duì)其生長(zhǎng)質(zhì)量進(jìn)行了表征。結(jié)果表明，采用5S間斷生長(zhǎng)的GaAs／AlAs DBR材料質(zhì)量和界面質(zhì)量?jī)?yōu)于無(wú)間斷生長(zhǎng)，并且10對(duì)GaAs／AlAs DBR的質(zhì)量?jī)?yōu)于30對(duì)，說(shuō)明DBR對(duì)數(shù)越多，周期厚度波動(dòng)越大，材料質(zhì)量越差。優(yōu)化生長(zhǎng)得到的30對(duì)GaAs／AlAsDBR的反射率大于99％，中心波長(zhǎng)為1316nm，與理論設(shè)計(jì)結(jié)構(gòu)的模擬結(jié)果基本一致，可用作1．3μm垂直腔面發(fā)射激光器（VVSEL）直接鍵合的反射腔鏡。

Abstract:基于動(dòng)態(tài)材料模型（DMM），建立了Ti2AlNb基合金（Ti-22Al-25Nb）在溫度94012-1060℃，應(yīng)變速率0．001s^-1-10s^-1范圍內(nèi)的加工圖，并利用該圖分析了合金的高溫變形特性。結(jié)果發(fā)現(xiàn)：在溫度94012～97012，應(yīng)變速率0．4s^-1～10s^-1和溫度970℃—1060℃，應(yīng)變速率1s^-1～10s^-1范圍為流動(dòng)失穩(wěn)區(qū)，前者范圍內(nèi)主要發(fā)生絕熱剪切變形和45°角剪切開(kāi)裂，功率耗散率達(dá)到最小值；后者區(qū)域內(nèi)以局部塑性流動(dòng)和縱向開(kāi)裂為主，功率耗散率小于33％。熱加工圖的其余部分為塑性加工的“安全區(qū)”，主要發(fā)生再結(jié)晶。在溫度94012～970℃，應(yīng)變速率0．001s^-1-0．4s^-1范圍，以α2／O相板條球化為主；在溫度970℃～1030℃，應(yīng)變速率0．001s^-1～1S^-1范圍，功率耗散率為35％-45％，呈現(xiàn)連續(xù)再結(jié)晶特征。在溫度1030℃～1060℃。麻蠻諫率0．001s^-1-0.1s^-1范圍。功率耗散率為45％～66％。達(dá)最大值,發(fā)生連續(xù)再結(jié)晶晶粒長(zhǎng)大。

Abstract:利用改裝的Arcan夾具對(duì)鋁合金（6063）的蝶形試樣進(jìn)行0°，30°，45°，60°，90°的拉伸及拉伸卸載試驗(yàn)，研究了鋁合金在不同應(yīng)力狀態(tài)下變形及損傷機(jī)理。結(jié)果表明：鋁合金在不同應(yīng)力狀態(tài)下的工程應(yīng)力一應(yīng)變曲線(xiàn)明顯不同。0°加載時(shí)，在蝶形中心產(chǎn)生微孔洞，微孔洞之間剪切，從而產(chǎn)生了微裂紋。隨著微裂紋的擴(kuò)展、連接導(dǎo)致試樣斷裂。隨著試樣中三軸應(yīng)力度的減小，在蝶形試樣中心的剪切應(yīng)力不斷增大，同時(shí)在蝶形試樣中的剪切變形帶越來(lái)越集中。顯微裂紋首先在剪切帶中產(chǎn)生，隨著微裂紋的擴(kuò)展導(dǎo)致試樣的斷裂。90°拉伸時(shí)，在蝶形中心形成明顯的剪切變形帶。90°加載時(shí)，在試樣中產(chǎn)生的剪切帶是形變剪切帶而非相變剪切帶。利用有限元軟件ABAQUS對(duì)不同角度拉伸試驗(yàn)進(jìn)行模擬，從而得出了不同應(yīng)力狀態(tài)下的塑性區(qū)的形狀和大小。

Abstract:采用粉末冶金＋熱擠壓工藝制備SiCp/Al復(fù)合材料，測(cè)定其力學(xué)性能。利用X射線(xiàn)衍射分析復(fù)合材料物相的組成，用金相顯微鏡、掃描電鏡和透射電鏡分析其微觀組織結(jié)構(gòu)。結(jié)果表明，SiC顆粒在鋁基體中分布比較均勻，SiC顆粒與基體結(jié)合良好；基體主要是α-Al，強(qiáng)化相β-Mg2Si和彌散相（Fe，Mn，Cu）3Si2Al15（體心立方結(jié)構(gòu)，晶格常數(shù)1．28nm）；SiCp／Al界面則為Al和Mg元素?cái)U(kuò)散到SiC表面的SiO2層形成的20nm-30nm無(wú)定形層；復(fù)合材料的斷裂機(jī)制主要是SiC顆粒斷裂和SiCp／Al界面塑性撕裂：復(fù)合材料在變形過(guò)程中，SiC顆?？勺柚沽鸭y的擴(kuò)展。

Abstract:The influence of trace Zr on the quench sensitivity of 7055 type aluminum alloy was investigated by ambient tensile testing, optical microscopy(OM), scanning electron microscopy(SEM) and transmission electron microscopy(TEM). The results showed that the addition of trace Zr increased the quench sensitivity for the strength of alloy, but decreased the quench sensitivity for elongation, especially when the Zr amount was not less than 0.1%. The recrystallization occurred in the Zr-containing alloy not only increased the amount of random high angle grain boundaries, but made Al3Zr dispersoids losing the coherency with the matrix. As a result, the nucleation sites increased for heterogeneous precipitation during slow quenching, and the quench sensitivity of strength increased. The reasons for the decreased quench sensitivity of elongation were mainly due to the inhibition of recrystallization and the grain refining effect by Zr adding.

Abstract:分別采用光學(xué)顯微鏡、掃描電子顯微鏡、X射線(xiàn)衍射和顯微硬度等測(cè)試手段，研究了激光快速成形高強(qiáng)高韌損傷容限型TC21鈦合金的沉積態(tài)組織。結(jié)果表明：TC21沉積態(tài)有著粗大的沿沉積高度方向外延生長(zhǎng)的原始聲柱狀晶，僅最后一層熔覆層頂部為較細(xì)小的聲等軸晶。宏觀上存在明暗兩個(gè)組織區(qū)域，明區(qū)為針狀馬氏體區(qū)，位于最后十幾層熔覆層，暗區(qū)為網(wǎng)籃組織區(qū)。結(jié)合成形過(guò)程傳熱和組織轉(zhuǎn)變理論分析認(rèn)為，網(wǎng)籃組織是由明區(qū)的初始快冷凝固的馬氏體在成形過(guò)程中，經(jīng)受再熱循環(huán)的固溶時(shí)效作用轉(zhuǎn)變而來(lái)。隨著激光功率的增大，原始聲柱狀晶將粗化，暗區(qū)網(wǎng)籃組織中片狀口亦將長(zhǎng)大；明區(qū)硬度基本不變，暗區(qū)硬度略有下降。

Abstract:采用垂直向下的高梯度定向凝固裝置，研究了有熱溶質(zhì)對(duì)流的Al-38．5％Cu（質(zhì)量分?jǐn)?shù)，下同）過(guò)共晶合金中定向凝固組織變化。結(jié)果表明：熱溶質(zhì)對(duì)流造成界面前沿的溶質(zhì)成分（Cu元素）沿軸向減少。在定向凝固速率為5μm／s，合金溶質(zhì)成分減少到37％Cu以下時(shí)，合金定向凝固組織中，初生θ-Al2Cu相會(huì)消失，組織變?yōu)槿詈仙L(zhǎng)的共晶組織。合金凝固的固相分?jǐn)?shù)（fs）≥0．49時(shí)，組織變?yōu)槿詈仙L(zhǎng)共晶組織所對(duì)應(yīng)的溶質(zhì)成分的理論計(jì)算結(jié)果與實(shí)驗(yàn)結(jié)果相吻合。

Abstract:采用Co基自熔合金＋塊狀WC混合粉末進(jìn)行送粉激光熔覆并獲得熔覆層，對(duì)熔覆層在不同溫度下加熱后空冷至室溫，觀察相應(yīng)熔覆層的顯微組織變化。結(jié)果表明：熔覆層850℃再加熱處理，可以實(shí)現(xiàn)去應(yīng)力退火的目的。Co基自熔合金基體的顯微組織在850℃以上開(kāi)始不穩(wěn)定，當(dāng)受到高于此溫度沖擊時(shí)，發(fā)生形態(tài)和顯微組織結(jié)構(gòu)的變化。對(duì)熔覆層中的塊狀WC進(jìn)行再加熱，當(dāng)加熱溫度達(dá)到1000℃以上時(shí)，塊狀WC會(huì)發(fā)生離散，分化成細(xì)小的WC顆粒。產(chǎn)生這種現(xiàn)象的根本原因是塊狀WC具有先天的超細(xì)纖維、顆?；旌辖Y(jié)構(gòu)。

Abstract:運(yùn)用電化學(xué)方法對(duì)工業(yè)純Ti，Ti6Al4V合金和TAMZ合金在人工唾液中的電化學(xué)行為進(jìn)行了研究，探討了溶液pH值對(duì)Ti合金電化學(xué)性能的影響。結(jié)果表明，在人工唾液中，TAMZ合金具有最佳電化學(xué)穩(wěn)定性，腐蝕速率最低。Ti合金在人工唾液中存在較大的鈍化區(qū)間，電化學(xué)穩(wěn)定性按工業(yè)純Ti，Ti6Al4V合金和TAMZ合金的順序依次增強(qiáng)。隨溶液pH值升高，試樣的熱力學(xué)穩(wěn)定性增強(qiáng)。交流阻抗結(jié)果顯示，3種實(shí)驗(yàn)材料在人工唾液中具有優(yōu)異的耐蝕性能，腐蝕速率均在10^-2μm／a數(shù)量級(jí)，小于醫(yī)用級(jí)標(biāo)準(zhǔn)0．25μm／a。

Abstract:In natural environment, tarnish was observed on the surface of a commemoration silver coin of China. In order to identify the nature of the tarnishing film, optical microscope(OM), scanning electron microscope(SEM), electron microprobe analyses(EMPA), X-ray photoelectron spectroscopy(XPS), and X-ray diffraction(XRD) were applied to examine the tarnishing areas. It was found that the tarnishing position is uniformly moderate brown and several dark brown spots are randomly distributed. Groups of corrosion holes are distributed over the forging stress zones formed in the struck process. As result of surface analyses using EMPA, sulfur and oxygen were detected besides silver with uniformity of sulfur. Furthermore, distributions of silver and oxygen were in correspondence with the morphology of dark brown spots. XPS and XRD showed that components of spots are Ag2S, Ag2O and Ag2SO3, with a predominance of the first one. It could be estimated that the tarnish of silver is a series of electrochemical process that requires the presence of sulfur and oxygen.

Abstract:為了預(yù)測(cè)細(xì)晶鎢合金用作穿甲彈的高剪切毀傷效應(yīng)，采用機(jī)械合金化（MA）和噴霧干燥-熱還原兩種方法制備含稀土的超細(xì)93W-Ni-Fe-Y2O3復(fù)合粉末，利用冷等靜壓液相燒結(jié)的方法制備Ф20mm-Ф25mm的晶粒度小于8μm的鎢合金棒材。利用Hopkinson壓桿裝置對(duì)細(xì)晶鎢合金進(jìn)行了高應(yīng)變率（〉10^3／s）下的動(dòng)態(tài)力學(xué)性能研究，分析了應(yīng)變、應(yīng)變率、Y2O3等因素對(duì)細(xì)晶鎢合金棒材的動(dòng)態(tài)性能的影響。結(jié)果表明：鎢合金在高應(yīng)變率下會(huì)出現(xiàn)應(yīng)變強(qiáng)化和熱軟化效應(yīng)，在低應(yīng)變時(shí)應(yīng)力隨著應(yīng)變的增加而增加，當(dāng)應(yīng)變達(dá)到0．03后，應(yīng)力隨著應(yīng)變的增加呈鋸齒狀上升趨勢(shì)。鎢合金在高應(yīng)變率下會(huì)出現(xiàn)應(yīng)變率強(qiáng)化效應(yīng)，隨著應(yīng)變率的增加，應(yīng)力增加。添加Y2O能提高材料的最大應(yīng)力強(qiáng)度，提高鎢合金的動(dòng)態(tài)力學(xué)性能。

Abstract:The ion selective film of Nafion was used to modify the iridium oxide electrode, and it is found that the coated ion selective film on the electrode improves the resistance to the interference of oxidative/reductive negative ions. SEM was used to observe the pore size distribution on the surface and cross-section of the coated selective film on the electrode for the purpose of optimizing the preparation process of the film. Cyclic voltammetry experiment was carried out to study the electrochemical behavior of the Nafion-coated electrode. The ion selective mechanism is suggested based on the calculation of positive/negative ion transport coefficient, i. e. t+ and t-, using the method of film potential measurement.

Abstract:制備了高電導(dǎo)的La0．5Sr0.5CoO3塊樣，其800℃電導(dǎo)率為238S／cm。通過(guò)磁控濺射將La0.5Sr0．5CoO3涂覆在Fe-13Cr合金表面，再進(jìn)行800℃等溫氧化100h。SEM分析發(fā)現(xiàn)，F(xiàn)e-13Cr基體中的Cr和Mn向涂層表面外擴(kuò)散，同時(shí)涂層中的La，Sr及Co原子向合金基體內(nèi)部擴(kuò)散。電阻測(cè)試發(fā)現(xiàn)，氧化過(guò)程中，形成的反應(yīng)層并沒(méi)有顯著降低試樣的面電阻，800℃等溫氧化100h后的面電阻為6mΩ·cm^2。

Abstract:Using pulsed laser deposition method, the La0.82Te0.18MnO3 thin film was prepared on LaAlO3 (012) single crystal substrate. The structure of the film studied by X-ray diffractometry shows that the film has perovskite pseudocubic structure, and is of preferential orientation (012). The R-T curves show the metal-insulator transition (MIT) and CMR effect. And the TMI are 283 K and 303 K for 0 T and 0.7 T, respectively, and they are both near room temperature. The maximum MR is 30.6% at 0.7 T. Correspondingly, the peak temperature at the maximum MR is 263 K. This shows that the films display CMR effect in the mental region. Moreover, the magnetoresistance ratio at the room temperature (303 K) is 4.8% at 0.7 T. The results show that the data satisfy R=P1+P2T2+P3T4.5 for TTMI, it is satisfied with small polaron model. The effect of the continuous wave laser (532 nm, 40 mW) on the film was also investigated. Below TMI, the resistance increased under photo inducing. Above TMI there was a decrease of the resistance. The maximum photoinduced resistance change is 33.6%. This is attributed to the change of the magnetic order in the film because of photoinducing, which might reduce the double exchange, and change electronic transport.

Abstract:Diamond film wafers were prepared by high power DC-plasma jet CVD method. The microstrures and the orientation of grain growth for the diamond film were studied by XRD, OM. SEM and Raman spectroscop. The results showed that grains grew in random orientation. Atom hydrogen etching benefited the nucleation and growth of crystal embryo. Methane concentration has important influence on the preferentially orientated growth of the grains. Upon a low methane concentration, (111) facet of the diamond film grew in preferential orientation, and an octahedron crystal was formed. Finally the optical diamond film with uniform center and edge, high quality was prepared. Adopting high power DC-plasma jet CVD method, the speed of growth of diamond was lower. Meantime, the vacancies and vacancy clusters were also found.

Abstract:設(shè)計(jì)并采用自蔓延燃燒預(yù)熱，水介質(zhì)緩沖雙向爆炸固結(jié)的方式制備了Mo／Cu功能梯度材料（FGM），觀測(cè)了Mo／Cu FGM的顯微組織并分析了固結(jié)過(guò)程。對(duì)各層的密度、硬度、電導(dǎo)率等進(jìn)行了測(cè)量和分析。發(fā)現(xiàn)隨著Cu含量的增多，材料的密度平緩遞減但相對(duì)密度逐漸增大，硬度降低，電導(dǎo)率升高。相對(duì)密度從Mo層的94．2％到Cu層的98．4％，試樣整體的相對(duì)密度達(dá)95．5％。Mo／CuFGM第1層與第2層間的剪切強(qiáng)度為214．8MPa；Mo／CuFGM第3層，第4層的熱導(dǎo)率分別為204．76W·m^-1·K^-1和249．71W·m^-1·K^-1。

Abstract:7A60 alloys were prepared by spray deposition and casting techniques. The microstructures of the spray deposited and cast 7A60 alloys were studied using scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The results indicate that the cast 7A60 alloy exhibits coarse grains and macrosegregation. The microstructure of the spray-deposited Al-Zn-Mg-Cu alloy is composed of the refined, equiaxial grains without obvious segration. Compared with the traditional technique, the spray deposition technique increased cooling rate greatly, refine the microstructure of 7A60 alloy obviously.

Abstract:研究了微量Sc，Zr對(duì)Al-Zn-Mg-Cu合金組織性能的影響。結(jié)果表明：?jiǎn)为?dú)添加0．18％Zr，合金抗拉強(qiáng)度和延伸率明顯低于單獨(dú)添加0．18％Sc，但再結(jié)晶抑制效果優(yōu)于單獨(dú)添加0．18％Sc。復(fù)合添加Sc，Zr較單獨(dú)添加Sc或Zr具有更好的晶粒細(xì)化作用，較強(qiáng)的固溶強(qiáng)化作用和再結(jié)晶抑制效果。在Zr含量一定的條件下，合金強(qiáng)度和延伸率隨Sc添加量增加而提高。強(qiáng)度和延伸率增加與所析出的LI2結(jié)構(gòu)的Al3Sc，Al3（Sc，Zr）粒子釘扎位錯(cuò)和亞結(jié)構(gòu)，析出粒子數(shù)量增加、彌散度增大、分布均勻性提高、析出的η＇相所占的體積分?jǐn)?shù)增加有關(guān)。當(dāng)Sc，Zr復(fù)合添加量達(dá)到0．50％Sc＋0．18％Zr時(shí)，合金經(jīng)固溶處理后發(fā)生部分再結(jié)晶，抗拉強(qiáng)度和延伸率大大降低。合金強(qiáng)度和延伸率降低與晶內(nèi)、晶界大量析出粗大難熔的DO23結(jié)構(gòu)的Al3（Sc，Zr）粒子有關(guān)。

Abstract:設(shè)計(jì)了Mg-Al-Cu系的3種新合金AC33，AC53和AC63。發(fā)現(xiàn)3種實(shí)驗(yàn)合金的相組成相同：δ-Mg基體＋（δ-Mg＋Mg2Al2Cu3）共晶＋（δ-Mg＋Mg17Al2＋Mg2Al2Cu3）三元共晶。實(shí)驗(yàn)合金的室溫力學(xué)性能優(yōu)良。3種實(shí)驗(yàn)合金在200℃，50MPa條件下的蠕變抗力明顯優(yōu)于AZ91C合金，其中AC53合金的抗高溫蠕變性能最優(yōu)。Cu從以下途徑影響了Mg-xAl合金的蠕變特性：Cu的添加抑制了Mg17Al12相的析出，使合金耐熱性提高。該系列實(shí)驗(yàn)合金單從力學(xué)性能和抗蠕變性能來(lái)看，是非常有發(fā)展?jié)摿Φ摹?/p>

Abstract:采用快速冷凍沉淀法制備了非晶態(tài)納米氫氧化鎳粉體材料。討論了反應(yīng)體系的pH值、溫度和表面活性劑等因素對(duì)粉體特性的影響。結(jié)果表明，當(dāng)選擇表面活性劑為T(mén)ween80，反應(yīng)體系的pH=11-12，T=55℃，反應(yīng)時(shí)間為1h時(shí)，所制備的非晶氫氧化鎳粉體粒度為30nm左右，形貌近似球形。將樣品粉體作為MH-Ni電池正極活性材料，其充電電壓低，電化學(xué)極化阻抗小，放電平臺(tái)高（1．258V），且平穩(wěn)時(shí)間較長(zhǎng)，放電比容量達(dá)349．85mAh／g。

Abstract:IrTa-X mixed metal oxide (MMO) coating titanium anode was prepared by thermal decomposition process. The electrochemical performance of Ti anode was investigated by means of polarization curves. The surface morphology of the coating was observed by SEM. The relationship between the anode lifetime and coating thickness and the anode current density was studied. The results indicate that the Ti anode has the superior electrochemical performance and the longer lifetime. So the MMO anode will be the promissing auxiliary anode of impressed current cathodic protection for reinforced concrete structure.

Abstract:In order to improve the wear resistance of titanium alloys, a process of oxygen-permeation & diffusion-solution (OP-DS) was developed, by which no oxide film was formed on the surface. The titanium alloy of TC11 was studied by TGA, SEM, XRD, XPS and micro-hardness tester at high temperature. The results indicate that the hardening depth and the hardness of surface layer can be remarkably enhanced, and the surface oxide film is decreased by the OP-DS process. The pre-OP treating time exhibited significant effect on the following DS treatment, even a hardened layer without oxide scale could be produced by proper combination of OP and DS. The OP-DS process was also discussed in terms of thermal diffusion mechanism.

Abstract:采用機(jī)械合金化法和真空熔煉法制備了不同顯微組織的Ni-20Cr（質(zhì)量分?jǐn)?shù)，％，下同）合金，并研究其在950℃，75％Na2SO4＋25％K2SO4（質(zhì)量分?jǐn)?shù)，下同）鹽膜下的熱腐蝕行為。結(jié)果表明：細(xì)晶的機(jī)械合金化Ni-20Cr合金熱腐蝕后表面形成了單一連續(xù)的Cr2O3外氧化膜，有效地阻止了硫的向內(nèi)擴(kuò)散，延長(zhǎng)了熱腐蝕過(guò)程的孕育期，呈現(xiàn)出較普通晶粒尺寸的熔煉Ni-20Cr合金更好的抗熱腐蝕性能。

Abstract:Structure and forming process of the Ti/Al diffusion bonding joints were studied by means of scanning electron microscopy (SEM), X-ray diffractometry (XRD) and shear strength measurement. The TA2 and L4 were used as bonding couples. The results showed that the forming process of joints included four stages. The primary and unique phase was TiAl3 from the diffusion reaction for long time. There was a delay time tD before TiAl3 appeared, mainly affected by temperature. The joint strength depended on the metallurgical combination percentage and interface structure of diffusion zone, reaching or even exceeding the strength of L4 when the TiAl3 formed like sheet and layer. The shearing fracture of joints occurred on the interface of Al and diffusion zone or in the Al-based metal.

Abstract:In order to improve the inner quality of superalloy master ingots, a technology of vacuum electromagnetic casting (V-EMC) was developed for the superalloy, i.e., applying electromagnetic stirring to the solidification process of vacuum casting. The effect of electromagnetic stirring on the inner quality of superalloy master ingots was studied with EPMA and optical microscope. The results show that the equiaxial crystals of superalloy master ingot can be effectively refined and increased, and the central shrinkage porosity and the dendritic segregation are greatly reduced, so the inner quality is obviously improved for the superalloy master ingots when electromagnetic stirring at a frequency of 50 Hz and a current of 60 A.

Abstract:在較高濃度的硝酸銀溶液中，采用水合肼為還原劑，PVP為保護(hù)劑的化學(xué)還原法制備了納米銀粉。通過(guò)對(duì)還原劑、保護(hù)劑用量和硝酸銀濃度、溫度、還原劑的加入方式、pH值等因素對(duì)納米銀粉粒度和形貌影響的考察，獲得了制備納米銀粉的工藝。在AgNO3濃度為0．6mol／L，PVP／Ag摩爾比為1．5，水合肼濃度為0．6mol／L，pH值為5～6，溫度為60℃的條件下，制備出了粒度均勻且粒度在50nm左右的納米銀粉。

Abstract:在含氟離子的水溶液中，采用Al粉直接置換還原Ni鹽的方法，實(shí)現(xiàn)了納米Ni在Al粉表面上的快速化學(xué)沉積，制備出核-殼結(jié)構(gòu)的Ni／Al復(fù)合粉末。探討了反應(yīng)的過(guò)程，利用粒度分析，SEM，XRD，BET，XPS等測(cè)試手段對(duì)復(fù)合粉末進(jìn)行了微觀測(cè)試和表征。結(jié)果表明：平均粒度為7．13μm的鋁顆粒表面包覆著一層納米Ni（其晶粒度為20．4nm），形成了殼層。

Abstract:Based on the main experiment parameters of DyFe2 alloy preparation by reduction-diffusion process: reaction temperature, holding time, added quantity of Ca and particle size of Fe, the BP neural network was established and used to predicate the transformation efficiency of DyFe2 alloy. The neural network was simulated by 44 groups of experimental data and was tested. It has been proved that the neural network has good performance to predict the transformation efficiency of DyFe2 alloy. This design of neural network is able to shorten the time of experiment, reduce the experiment cost, and optimize the preparation processes.

Abstract:On the basis of Zeta value measurement of the silver nanopowders prepared by DC arc plasma evaporation, the influences of supersonic dispersing time and surfactant concentration on the dispersing properties in alcohol solvent were studied systematically for the silver nanopowders by using polyvinylpirrolidone (PVP), cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulphate (SDS) and oleic acid as surfactants. The results show that the suspension dispersion effects increased up to a maximum, then decreased with the increasing of ultrasonic dispersing time, similar to the increase of surfactant concentration. PVP is the best dispersant for the four kinds of surfactant using in the experiments, the optimum dispersing condition is PVP of 1.5wt% for the ultrasonic dispersing time of 40 min.

Abstract:以硫酸亞鐵、硫酸鎳、碳酸鈉和石墨微球?yàn)橹饕希梅蔷喑珊斯に囍苽涑鏊涎趸F和堿式碳酸鎳均勻包覆石墨的前驅(qū)體微球：通過(guò)對(duì)前驅(qū)體進(jìn)行熱還原處理得到了晶粒約為50nm的γ-FeNi合金顆粒層包覆石墨的產(chǎn)物微球。利用SEM，EDS，XRD對(duì)前驅(qū)體和產(chǎn)物的形貌、成分、物相分別進(jìn)行了表征，并利用TG／DSC對(duì)前驅(qū)體熱分解過(guò)程進(jìn)行了分析。通過(guò)研究，得出了制備這種核．殼結(jié)構(gòu)復(fù)合微球的優(yōu)化工藝參數(shù)。

Abstract:采用經(jīng)高能球磨的超細(xì)93W-4.9Ni-2.1Fe預(yù)合金粉末，并添加少量的Re，經(jīng)壓制，燒結(jié)制取試樣。研究Re對(duì)93W-4.9Ni-2.1Fe合金性能和微觀組織的影響。用機(jī)械式拉力試驗(yàn)機(jī)測(cè)量試樣拉伸強(qiáng)度，用掃描電鏡觀察試樣拉伸斷1：3的形貌，用金相顯微鏡對(duì)試樣顯微組織進(jìn)行測(cè)試分析。結(jié)果表明：當(dāng)添加0％-0．8％Re（質(zhì)量分?jǐn)?shù)，下同）時(shí)，隨著Re添加量的增加，合金的相對(duì)密度穩(wěn)定在99．43％～99．49％，燒結(jié)樣品延伸率從不加Re時(shí)的26．47％降至0．8％Re時(shí)的14．71％，合金的抗拉強(qiáng)度由不加Re時(shí)的1025MPa增加到0．8％Re時(shí)的1142MPa，合金拉伸斷口收縮率由不加Re時(shí)的20．45％降至0．8％Re時(shí)的10．91％；隨著Re含量的增加，合金中W晶粒的穿晶解理斷裂的比例增加，而粘結(jié)相延性斷裂的比例減少；隨著Re含量的增加，合金中W晶粒尺寸明顯減小，由不加Re時(shí)的40μm-45μm減小到添加0．8％Re時(shí)的20μm-25μm。

Abstract:Rare-earth Mg-based hydrogen storage electrode alloys of LaMg2Ni9-xCox(x=0.3~6.0) and MlMg2Ni9-xCox(x=0.3~4.5) with different stoichiometric ratios were prepared by coprecipitation-reduction-diffusion method. Electrochemical analyses showed that the alloys prepared by this method can be easily activated; with x increasing, no obvious change for the activity numbers, and the discharge capacity decreased and the cyclic stability of alloy electrodes was effectively improved. Their activity numbers were larger than La-alloys, the discharge capacity decreased and the cyclic stability of mix-alloys was better than La-alloys. Structure analyses showed that the main phases of alloys were MgNi2 and LaNi5, the amount of LaCo5 phase and LaCo3 phase increased with Co content increasing.

Abstract:將Ag粉和Al2O3粉按不同配比（體積分?jǐn)?shù)，下同）配制后進(jìn)行高能球磨，然后燒結(jié)。研究不同Ag含量對(duì)試樣燒結(jié)性能與斷裂韌性的影響。結(jié)果表明，高能球磨可使顆粒細(xì)化。由于粒子尺寸細(xì)小，具有較高的表面能，使得試樣的燒結(jié)溫度明顯降低。并且第二相Ag粒子的添加也可明顯降低試樣的燒結(jié)溫度，但同時(shí)也不同程度地降低了試樣的相對(duì)密度。Ag粒子的添加量對(duì)試樣的斷裂韌性有較大影響。當(dāng)Ag含量從0％增加到5％時(shí)，斷裂韌性也隨之增大，當(dāng)Ag含量為5％時(shí)，試樣的斷裂韌性達(dá)到最大值5．12MPa·m^0.5。當(dāng)Ag含量從5％增加到10％時(shí)，由于相對(duì)密度急劇降低，使得試樣的斷裂韌性也隨之明顯降低。

Abstract:采用高能?chē)娡杓夹g(shù)在鋁合金表面制備出納米晶結(jié)構(gòu)層，利用金相顯微鏡（OM），掃描電子顯微鏡（SEM／EDS），透射電子顯微鏡（TEM）及X射線(xiàn)衍射儀（XRD）等設(shè)備對(duì)高能?chē)娡桎X合金表面層的顯微結(jié)構(gòu)及成分進(jìn)行分析。結(jié)果表明：在高能?chē)娡璞砻婕{米化過(guò)程中，彈丸中的Fe，cr原子在強(qiáng)制機(jī)械力的作用下轉(zhuǎn)移進(jìn)入鋁合金表面，在材料表層約30μm的深度范圍內(nèi)形成分布不均勻的合金化層。這可能是納米晶體中大量界面的形成使合金元素原子能夠快速擴(kuò)散和偏聚的結(jié)果。

Abstract:The permanent bulk magnets of Nd10.5Dy0.5Fe76.9Nb1Co5B6.1 were prepared by the process of field-activated sintering in this paper. The microstructure was discussed by XRD, SEM and so on. The results show that the optimal magnetic properties of Nd10.5Dy0.5Fe76.9Nb1Co5B6.1 (Br=0.6498 T, Hcj=714 kA/m, (BH)max=63 kJ/m3) magnets have been obtained while treated at 823 K for 300 s by field-activated sintering. The compressive strength increases as the increase of sintering temperature.

Abstract:采用一種以Sn作為添加劑的低溫瞬時(shí)液相燒結(jié)方法來(lái)制備Terfenol-D。分別研究了粉末粒度、Sn含量、成型壓力、燒結(jié)工藝對(duì)樣品磁性能（包括磁致伸縮性能）和力學(xué)性能的影響。獲得了在12×79．6kA／m磁場(chǎng)下，與磁場(chǎng)平行方向磁致伸縮值為5．46×10^-4。的燒結(jié)樣品，其制備條件為：粉末粒度〈75μm，Sn含量為8％（質(zhì)量分?jǐn)?shù)，下同），成型壓力為1．0GPa，在250℃持續(xù)燒結(jié)150s。