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Abstract:將Zr-4和成分接近ZIRLO的3#合金樣品置于高壓釜中,經(jīng)過360℃,18.6 MPa的0.01 mol/L LiOH水溶液腐蝕1 50 d后,增重分別達到310 mg/dm^2和82 mg/dm^2,3#合金的耐腐蝕性能明顯優(yōu)于Zr-4.用透射電鏡、掃描電鏡和掃描探針顯微鏡研究了兩種樣品經(jīng)過70 d和150 d腐蝕后,氧化膜不同深度處的顯微組織和晶體結(jié)構(gòu);研究了氧化膜的斷口形貌和氧化膜的表面形貌.結(jié)果表明：Zr-4氧化膜中的空位比3#合金氧化膜中的更容易通過擴散凝聚形成孔洞簇和晶界微裂紋,也容易發(fā)展成平行于氧化膜/金屬界面的裂紋,導致腐蝕轉(zhuǎn)折提早發(fā)生,這與Li^＋和OH^-滲入氧化膜后降低氧化鋯表面自由能的程度有關(guān).從氧化膜表面晶粒形貌判斷,Zr-4樣品形成氧化鋯后的表面自由能比3#合金樣品形成氧化鋯后的低,這是合金成分不同引起的一種差異,也可能是Zr-4樣品在LiOH水溶液中的耐腐蝕性能比3#樣品差的一個重要原因.

Abstract:Zr-Al-Ni-Fe alloy series with different compositions were designed according to the criteria of constant electron concentration and atomic size. XRD results indicate that only the four alloys near the Zr-Al-Ni ternary system formed the bulk metallic glass. It is revealed by DSC and DTA curves that the best composition forming glass is Zr60.7Al15.5Ni15.5Fe8.3 with the thermodynamic characteristic parameters of Tg=710 K, Tx=770 K, ?Tx=60 K, Tg/Tm=0.607, and Tg/Tl=0.552, respectively.

Abstract:采用化學共沉淀法摻金屬Nb,Ta和P到ITO材料中可使ITO(IndiumTinOxide)靶相對密度達到97%~99%,并且靶電阻率小于3.0×10-4??cm,其質(zhì)量損失率小于4.0%。采用直接摻雜法將TiO2納米粉末摻入到納米ITO粉末中可使ITO靶相對密度達到95%以上。當燒結(jié)溫度為l500℃時,摻Nb,Ta,P的ITO靶電阻率稍小于純ITO靶的電阻率。

Abstract:A mechanical analytical model is put forward for the three-dimensional isotropic reticulated porous metals under biaxial tension according to a simplified structural model in this study. The relationship between biaxial nominal stresses and porosity at the beginning of breakdown is derived for these materials from this analytical model. Based on the resultant relationship, the safety criterion can be further obtained for these foamed metals under biaxial loading. When the biaxial nominal stresses are equal to each other, the mathematical relationship between loading strength and porosity can be also gained for the foamed metals under biaxial equal loads. According to the typical experiment on nickel foam as an example, it is proved that these theoretical formulas well accorded with the practical ones. The safety criterion for the porous bodies under biaxial loading can be gotten from this model, which is not dealt with or difficult to do by other relative theories, such as Gibson-Ashby model.

Abstract:The precipitation processes of the ordered phases D022 and L1 2 in Ni75Al5.5V19.5 alloy at different temperatures were studied using the microscopic phase-field method. It is found that the supercooling degree is the main factor for the phase transformation. The D022 phase precipitates at a higher temperature firstly, then the L1 2 phase precipitates at the phase boundaries of D022 and disordered phases and round the interphase of D022 forming. The L1 2 phase grew towards the disordered matrix and the D022 phase nearly at the same time. Then at a lower temperature, the L1 2 phase precipitates firstly, then the D022 phase precipitates at the ordered interphase of L1 2 phase, which transforms from a nonstoichiometric phase to a equilibrium phase through spinodal decomposition and the dimension becomes smaller. The volume fractions of the two phases are almost equal at last. With the temperature decreasing, the precipitation mechanism of L1 2 phase transforms from the mixed pattern of non-classical nucleation and spinodal decomposition of higher temperature to the spinodal decomposition of lower temperature, but the precipitation mechanism of D022 phase transforms from the mixed pattern to the non-classical nucleation.

Abstract:Arc-glow plasma depositing technique is a new surface coating method. With the help of vacuum arc discharge, a cold cathode arc source continually emits ion beams of coating elements with high currency density and high ionizing ratio. Upon the ion bombard and diffusion work on, the surfaces of the parts form deposited layers, diffusion layers. In this study, a commercial magnesium alloy AZ91 was coated with Ti film layer. The corrosion behaviors of the coated samples have been studied by methods of measuring anodic polarization curves and salt spray test. Section and surface morphology of Ti film have been surveyed through scanning electronic microscopy (SEM), the composition analyzed by electron diffraction spectrum (EDS) and glow discharge spectrum (GDS). The results indicated that the coating of Ti effectively improved the anti-corrosion performance of AZ91.

Abstract:Energy deposition at the interface of the particles caused by micro-explosive welding in explosive consolidation of metal powders is analyzed by symmetrical impaction model of uncompressible liquid. Two-dimensional equation of energy in the flow field of explosive welding is deduced and solved by finite difference method. Then the distribution of the temperature in the flow field is calculated on the basis of considering the adiabatic compression. The results show that under an appropriate pressure the temperature rise near the welding interface caused by micro-explosive welding in explosive consolidation of metal powders will be higher than the melting point of the materials, and the thin melted layers are localized on the surfaces of the particles, the temperature rise increases with increasing of approaching flow velocity and impact angle.

Abstract:采用熔鹽電解法,在900℃熔鹽CaCl2中以燒結(jié)TiO2為陰極,石墨棒為陽極制備出了金屬鈦.研究了不同溫度下燒結(jié)陰極的形貌及其對電解反應(yīng)的影響.結(jié)果表明：600℃下燒結(jié)4 h的陰極具有良好電化學反應(yīng)性能;電解過程中脫氧速度不均勻;TiO2電極的還原是由外向內(nèi),由高價向低價再到金屬分步進行的;電解還原過程電流效率低約為15%.陰極的孔隙大小和顆粒尺寸會影響電極的反應(yīng)速度.

Abstract:The fretting fatigue behavior of TC4 titanium alloy was investigated using a cylinder-plane configuration. Through the observation of worn surface and cross-section, the formation and evolving process of the fretting debris and the effects during fretting fatigue were discussed. The variation of friction coefficient with time was analyzed. Based on the experimental results of TC4 titanium alloy, it is found that the damage mechanism of fretting fatigue was adhering wear, abrasive wear and contact fatigue, accompanying with oxidation wear. The fretting debris were formed from the break-off and crushing of the parent alloy, then oxidization to be the fragments during the fretting fatigue test. It promoted the abrasive wear and accelerated the fatigue failure due to the hard oxide particles in fretting debris. The friction coefficient rapidly increased with time in the initial stage, then kept stable in the stable stage.

Abstract:采用離子滲鍍技術(shù)在Ti6Al4V合金表面形成均勻致密的鉬氮陶瓷滲鍍層,對陶瓷層微動摩擦學性能進行研究.100000周次微動磨損試驗結(jié)果表明,滲鍍的Mo-N陶瓷層顯著提高了Ti6A14V合金的抗微動磨損能力.Ti6Al4V合金微動磨損機制是粘著與磨粒磨損的綜合效應(yīng),Mo-N陶瓷層微動磨損機制是犁削.

Abstract:Silver foils irradiated by atomic oxygen (AO) generated in a ground simulation facility were investigated by quartz crystal microbalance (QCM), scanning electron microscopy (SEM) and X-ray Diffraction (XRD). The experimental results show that the oxidation behaviour of silver foil exposed to AO exhibits two stages: forming a thick Ag2O film at first, then forming AgO in the upper layer of the oxide film by the reaction of Ag2O film with O. At the first stage, the oxide layer cracked and spalled due to the development of stresses, so that new silver surface exposed out, and the further fast oxidation happened.

Abstract:Ti-Fe-Cr-Ni-C composite coatings were deposited with a new process of Reactive Flame Spray (RFS) from the powders synthesized by the process of precursor-carbonization-composite, in which ferrotitanium and asphalt were used as raw materials. XRD and SEM were employed to analyze the phase composition and microstructure of the composite powders and coatings. The wear resistance of the coating was tested. The results show that the TiC/FeCrNi composite coating by RFS is composed of layers in which the round nanoscale TiC particles are dispersed within a metal matrix. The matrix consists of Cr0.19Fe0.7Ni0.11 and (Fe, Cr). Under the same condition of wear testing, the wear volume of the TiC/FeCrNi composite coating is one eighth of that of the Ni60 coating by normal flame spray.

Abstract:Using a first-principle pseudopotential plane-wave method, the energetic, geometrical and electronic structures of point defects are calculated for B2-RuAl intermetallic compound. Based on the calculation and comparison of the formation heat and formation energy for several kinds of point defective structures, the type and the geometrical configuration of point defects in B2-RuAl intermetallic compound are analyzed and forecasted. Results show that the major point defects in B2-RuAl intermetallic compound are vacancy or anti-site in the Ru sublattice, i.e., Ru vacancy and Al anti-site, but mainly Ru anti-site defect in rich-Ru alloy, and mostly Al anti-site defect in rich-Al alloy. These point defects emerge in the form of Ru-Ru double vacancy or Al-Al double anti-site configurations, namely, there are two vacancies or two Al atoms in the Ru sublattice. And they would be in the most stable structure when the double vacancies at Ru sites were in the first nearest neighborhood, or when the double Al atoms at Ru sites were in the third nearest neighborhood. In addition, the influences of above point defects on Cauchy pressre parameter(C12-C44)of B2-RuAl and NiAl were also compared. It is found that the decreasing of C12-C44 caused by point defects in RuAl is smaller than that in NiAl, so that the ductility of RuAl metallic compound with point defects at room temperature is better than NiAl.

Abstract:對一種加3%～5%（質(zhì)量分數(shù)）金屬Re的CoNiCrAly合金在1000℃空氣中進行了恒溫氧化實驗,利用X射線衍射、掃描電鏡和能譜分析研究其氧化行為.結(jié)果表明：與不加Re的合金相比,加Re合金在初期氧化階段增重較低;并且金屬Re加速了亞穩(wěn)過渡相θ-Al2O3向穩(wěn)定相α-Al2O3的轉(zhuǎn)變,有利于快速生成致密的α-Al2O3保護膜.

Abstract:Sn and In soft metal films, Al2O3 ceramic film and In/Al2O3 dual film were prepared with ion beam deposition technique. Sliding friction characteristics of these films against U-Nb alloy pin were evaluated by a pin-disc tribometer and Scan Electrical Microscopy (SEM). It had been found that the friction coefficients of sliding against SiC ceramics ball with smoothing surface decreased for the Sn and In films due to their very low strength, but increased against U-Nb alloy pin with engineering-coarse surface for the In film and In/Al2O3 dual film due to the adhesion between In and U-Nb alloy. Meantime, very thin Sn film resulted in increase of friction coefficient. The friction property would be improved only when the thickness of Sn film increased to a reasonable value. Otherwise, the friction coefficient of Al2O3 ceramics film against the U-Nb alloy with low strength did not decrease almost same as the results of Ta12W alloy because the U-Nb alloy was easy to be worn and transferred on the surface.

Abstract:利用鍵參數(shù)函數(shù)和尺寸因數(shù)對第四長周期過渡族金屬元素基準晶形成規(guī)律進行研究。發(fā)現(xiàn)可以用拋物線y=a-bx^2將準晶形成區(qū)與準晶不能形成區(qū)區(qū)分開，準晶形成區(qū)的準確率達到了93．12％。同時，發(fā)現(xiàn)拋物線的參數(shù)a，b可以由基體元素的相關(guān)參數(shù)確定，即a∝E,b∝EμR0^3.

Abstract:利用XRD,SEM和EDX對石墨表面鈦金屬化界面的物相、微觀組織及成分進行了分析.結(jié)果表明,金屬化石墨微觀組織呈層狀結(jié)構(gòu),依次為內(nèi)層（石墨）、過渡層、致密層及外層（Ti）,其中過渡層厚約為720 μm,致密層厚約為40 μm.XRD及EDX分析證實了致密層物相為碳化鈦,SEM分析證實了致密層與過渡層及Ti層結(jié)合牢固.但還發(fā)現(xiàn)在Ti層與致密層界面處存在短微裂紋,在致密層與過渡層界面處未有發(fā)現(xiàn),原因主要是材料間的熱膨脹系數(shù)差異產(chǎn)生熱應(yīng)力所致.并且還對石墨表面金屬化機理進行了探討.研究表明,其機理是通過金屬Ti與石墨發(fā)生界面反應(yīng)生成碳化鈦來實現(xiàn).

Abstract:研究了燒結(jié)NdFeB磁體強韌性和磁性能對速凝鑄帶厚度的依賴性.結(jié)果表明：磁體的抗彎強度隨著鑄帶厚度的減小而迅速增大,當鑄帶較薄時,帶內(nèi)的微細晶制粉時形成較多氧化的細小顆粒,它們能有效延緩燒結(jié)過程中的晶粒生長速度.由斷裂強度公式得知,晶粒越小,磁體抗彎強度越高,因此用0.38 mm厚鑄帶制成的磁體抗彎強度比0.45mm厚鑄帶制成的磁體大得多.同時,鑄帶厚度為0.45 mm時,帶內(nèi)晶粒尺寸分布較好（3 μm～5μm）,此厚度鑄帶制備的磁體磁性能可獲得最佳值.

Abstract:采用共沉淀BaTiO3為基,適量摻雜Nd2O3稀土氧化物及MgO與ZnO添加劑,獲得具有X7R溫度特性的低頻高壓MLC瓷料系統(tǒng),BaTiO3基瓷的平均晶粒尺寸小于0.8μm,居里點彌散成為居里區(qū).其介電性能為介電系數(shù)ε≥3000;容量變化率△C/C≤±15%;介電損耗tgδ≤120×10-4;體積電阻率ρv≥1012Ω·cm;擊穿場強Eb≥15 kV/mm.

Abstract:Bioactive calcium phosphate coatings on carbon/carbon composites were prepared by a cathode sonoelectrodepostion technique. The effects of electrodeposition time on the morphology, structure and composition of the coatings on carbon/carbon composites were investigated by SEM, EDAX, FTIR and XRD. The experimental results show that the plate-like crystals formed in initial stages of electrodeposition were identified to be CaHPO4.2H2O(DCPD). With the electrodeposition time elapsing, the formed needle-like precipitates were identified to be Ca10(PO4)6(OH)2(HA), the coating thickness and the n(Ca)/n(P) ratio increased continuously. The degree of crystallization of the coatings and the pH values of electrolyte decreased with the electrodeposition time increasing. The coatings were calcium-deficient apatite. In addition, the growth mechanism of coatings on C/C composites was also discussed.

Abstract:探討了MnO2和Nb2O5摻雜對Pb（Mn1/3Sb2/3）0.05Zr0.47Ti0.48O3（PMSZT）材料相組成、顯微結(jié)構(gòu)、電性能及溫度穩(wěn)定性的影響.結(jié)果發(fā)現(xiàn)：合成溫度900℃,可以得到鈣鈦礦結(jié)構(gòu);隨著摻雜量的增大,四方相的含量減少,準同型相界向三方相移動;當MnO2過量0.1%,Nb2O5摻雜0.05%（均為質(zhì)量分數(shù)）時,εT33/ε0,d33和Kp達到最佳值;隨著MnO2和Nb2O5摻雜量增加,Qm值下降,諧振頻率變化率隨溫度變化由正到負.

Abstract:在不同襯底溫度下用脈沖激光沉積法（PLD）在n型硅（111）襯底上生長ZnO薄膜.通過對薄膜進行的X射線衍射（XRD）、傅里葉紅外吸收（FTIR）、光致發(fā)光譜（PL）、透射電子顯微鏡（TEM）和選區(qū)電子衍射（SAED）的測量,研究了襯底溫度對PLD方法制備的ZnO薄膜的結(jié)晶質(zhì)量、發(fā)光性質(zhì)以及微觀結(jié)構(gòu)的影響.發(fā)現(xiàn)在600℃的襯底溫度下可以得到結(jié)晶質(zhì)量最佳的ZnO薄膜.隨著晶粒直徑的減小,出現(xiàn)量子限制效應(yīng),在紅外吸收和光致發(fā)光中的峰位均產(chǎn)生了藍移.

Abstract:采用直流勵磁磁控濺射法制備NdFeB稀土永磁薄膜.研究分析了襯底預(yù)熱與定向沉積法對薄膜結(jié)構(gòu)和磁性能的影響.實驗結(jié)果表明：定向沉積技術(shù)制備出的NdFeB薄膜表面形成單一方向的柱狀晶,該柱狀晶生長方向垂直于薄膜表面,使薄膜具有良好的磁各向異性,薄膜矯頑力大大提高,H⊥/H∥比值改善.在預(yù)熱溫度200℃逐漸加熱到500℃并保溫10 min時,薄膜磁性能最佳.

Abstract:利用回轉(zhuǎn)振動粘度儀在液相線以上較大溫度范圍內(nèi),測量了In-55%Sb（質(zhì)量分數(shù)）亞共晶合金熔體在不同的升降溫過程中的粘度.實驗結(jié)果表明,熔體經(jīng)歷的熱歷史對其粘度具有顯著的影響.熔體在降溫過程中的粘度高于升溫過程中,在過熱100℃后的降溫過程中熔體的粘度較之無過熱的降溫過程中要低.在不同的熱過程中,粘度發(fā)生轉(zhuǎn)折變化的溫度不同,在升溫過程中,發(fā)生在850℃左右,在過熱100℃和無過熱的降溫過程中,分別發(fā)生在750℃和650℃左右.熔體粘度的突變反映了熔體結(jié)構(gòu)在相應(yīng)溫度的突然變化.

Abstract:在中溫平板型固體氧化物燃料電池（ITSOFC）設(shè)計中,可以采用金屬作為連接材料.Fe-16Cr合金是較為理想的金屬連接材料,它存在的主要問題是連接體陰極側(cè)表面的高溫氧化和腐蝕,會導致電池性能的迅速降低.本研究采用空氣等離子噴涂的方法噴涂了La0.8Sr0.2MnO3-σ（LSM）鈣鈦礦型保護涂層在金屬連接板的表面,并討論了主要過程參數(shù)及其作用效果.研究發(fā)現(xiàn),噴涂后熱處理是降低涂層孔隙率的有效方法,經(jīng)噴涂-熱處理后,涂層的孔隙率可降至1%以下.等離子噴涂LSM保護涂層后,Fe-16Cr合金的耐高溫氧化性能明顯提高,氧化速率降低了76%.

Abstract:研究了熱處理(T6強化處理及純時效硬化處理)對滲流法生產(chǎn)的3種開孔泡沫鋁合金在動態(tài)(~2.1×103s-1)和準靜態(tài)(1.0×10-3s-1)下的壓縮力學性能及能量吸收特性的影響。分別在MTS810材料試驗機和分離式Hopkinson壓桿(SHPB)上對3種泡沫鋁合金材料進行了準靜態(tài)及動態(tài)壓縮實驗。實驗結(jié)果表明:與制備態(tài)相比,經(jīng)時效硬化處理及T6強化處理的泡沫Al-Mg-Si合金和泡沫Al-Cu-Mg合金的動、靜態(tài)壓縮強度提高、平臺區(qū)縮短,在一定應(yīng)變下單位體積吸收的能量提高,而且均表現(xiàn)出對應(yīng)變率的敏感性。而熱處理對泡沫Al-Mg合金的動、靜態(tài)壓縮性能均沒有影響,表明熱處理對泡沫金屬的作用與構(gòu)成泡沫的基體金屬關(guān)系密切,但與對應(yīng)的實體金屬的情況不同。須注意的是泡沫Al-Mg-Si合金和泡沫Al-Cu-Mg合金的純時效硬化處理,也可以在一定程度上提高其壓縮強度及吸能能力,與T6強化處理相比不需要固溶處理,不僅可以降低熱處理成本,而且還避免了在水中淬火時對泡孔結(jié)構(gòu)的破壞。實驗結(jié)果還表明,泡沫Al-Cu-Mg合金的應(yīng)變率敏感性受熱處理路線的影響,而泡沫Al-Mg-Si合金的卻不受影響。由于不同合金經(jīng)相同熱處理后會產(chǎn)生不同的沉淀硬化相甚至沒有硬化相,因此,可以得出熱處理對泡沫金屬性能的影響主要取決于制備泡沫的基體金屬。

Abstract:In order to improve the quality of hollow Cu tubes, a horizontal continuous casting technology was developed in a pilot scale by using electromagnetic field of commercial frequency, and the effect of electromagnetic field on structure and mechanical properties were studied. The results show that the structure of hollow Cu tubes is refined substantially with the application of electromagnetic field and the average grain grand is increased from 3.1 to 8.3 and the uniformity along the circumference of the structure is improved obviously at the same time. The tensile strength is increased by 40% and the elongation is improved by 50% averagely if compared to those without electromagnetic field.

Abstract:從銥鹽和配體2,2,6,6-四甲基-3,5-庚二酮（thd）出發(fā)合成了一種新的β二酮前驅(qū)體Ir（thd）3,通過元素分析、紅外光譜、核磁共振氫譜等手段對合成的前驅(qū)體進行了結(jié)構(gòu)表征.熱重分析表明,當溫度升到290℃,前驅(qū)體基本揮發(fā)完全.使用合成的前驅(qū)體通過MOCVD沉積制備銥薄膜,利用XRD和AFM分析手段對薄膜的結(jié)構(gòu)和表面形貌進行了表征.結(jié)果表明,所得到的薄膜的物相為銥晶相,無其它的雜質(zhì)峰存在,薄膜表面連續(xù)、致密.

Abstract:Dynamic shear properties of the tungsten heavy alloys containing 90% to 97% W (mass) were investigated using a hat-shaped specimen on the Hopkinson rod of Split Compression at a shear strain rate of 105 s-1. The results show that the dynamic shear strength increased and the shear strain decreased with the tungsten content increasing. The shear strength increased linearly with the increase of volume fraction of tungsten particles in the alloys. The shear fracture surface mainly exhibits tungsten grains split and matrix phase rupture, and the split proportion of tungsten particles equaled approximately to the volume fraction of tungsten particles.

Abstract:采用化學氣相沉積方法,在1200℃～1600℃溫度范圍內(nèi),于不同的NH3流量條件下,合成了Si/C/N納米粉體,研究了粉體的制備工藝、成分、相組成與其微波介電性能之間的關(guān)系.結(jié)果表明：NH3流量增加,粉體中N含量升高,隨著合成溫度的提高,粉體的晶化程度增強,主要為β-SiC相.在SiC晶格中固溶有N原子,且N原子的固溶量隨合成溫度升高而減少.Si/C/N納米粉體中SiC微晶含量,以及SiC微晶中固溶的N原子濃度對粉體的ε＇,ε（＂）和損耗因子tgδ（ε＂/ε＇）起著重要作用.N原子固溶所導致的極化馳豫損耗和漏導損耗是Si/C/N納米粉體具有吸波性能的主要機理.

Abstract:采用液相共沉淀方法,以ZnSO4·7H2O為原料,GaCl3為摻雜化合物,NH4HCO3為沉淀劑合成堿式碳酸鋅前驅(qū)體,通過在H2氣氛下煅燒,制得Ga3+均勻摻雜的納米氧化鋅導電粉體.利用SEM,TEM,XRD,XPS和BET等分析手段對粉體的性能進行表征.結(jié)果表明,這種方法合成的導電氧化鋅粉體材料顆粒尺寸較小、粒度分布均勻(約在20 nm～40 nm的范圍內(nèi)),顆粒呈類球狀形貌,具有較好的分散性能.研究了Ga3+摻雜對氧化鋅粉體導電性能的影響.結(jié)果表明,在Ga3+摻雜量為2.2mol%時,制得的氧化鋅粉體的導電性能最好,體積電阻率達到2.0Ω·cm.

Abstract:This paper investigates the intermetallic compound on the interface between AuSn solder and Au or Au/Ni metallization layer after laser soldering by SEM and EDX analysis. The effects of laser power and heating time on the evolution of intermetallic compounds on the interface are discussed. The results show that the components of Jntermetallic compound depart from the eutectic arrest due to Au dissolving quickly into the solder near the interface and forming a stable AusSn at the interface on the condition of laser heating and cooling quickly. With the increase of laser power and heating time, the undissolved Au layer becomes thinner and the AusSn grows into the solder.

Abstract:Silver nanoparticles were prepared by the reduction reaction of silver nitrate solution with sodium hypophosphite in polyvinylpyrrolidone solution. The silver sol was coagulated by adding ammonia solution. Some technical conditions, such as pH value, ammonia concentration, ammonia dropping velocity and stirring rate were tested in order to get silver nanoparticles by filtrating silver sols. The results showed that the separation of solid silver nanoparticles with liquid solution was improved and the silver nanoparticles with different sizes were prepared using this method. The silver powders with particle size of 10 nm~20 nm were successfully separated from the silver sol by adding mixed solution of flocculent and organic alkaline agents. This process is simple and ordinary, needs some simply apparatuses only and consumed less energy with a high silver production capacity. Therefore, it is feasible for industrialized preparation of silver nanoparticles. The products were analyzed by transmission electron microscope (TEM) and X-ray diffraction (XRD) and shown that the particles were pure metal silver with high dispersible spherical form and diameters from 10 nm to 40 nm.

Abstract:A qualitative study on the effects of humidity on activity of aluminum nanoparticles has been reported in this letter. The Al nanoparticles were synthesized by the process of hybrid induction and laser heating (HILH). In order to understand the stability of the oxide coating from aluminum nanoparticles, the Al nanoparticles were examined using high-resolution transmission electron microscopy (HRTEM) and the thermal behaviors were identified by DSC-TG. It was found that a compact amorphous oxide layer of 3 nm in thickness covered the original Al nanoparticles. After stored for 8 weeks, the oxide layer grew up to 5 nm in thickness, and the oxidation diffused to the interior of Al nanoparticles. The results indicate that the activity of Al nanoparticles is deeply influenced by the environment, especial the humidity. A higher relative humidity would accelerate the aging of Al nanoparticles. The DSC-TG results show that the oxidation of Al nanoparticles occurs at least in two steps.

Abstract:用真空吹鑄法制備了直徑為2 mm的Mg65Cu25Y10-xTbx（x=0,2,4,6,8,10）塊體非晶合金棒,采用X射線衍射分析（XRD）、差熱分析（DTA）分別對非晶合金的結(jié)構(gòu)和形成能力進行了研究.結(jié)果表明：Mg65Cu25Y10-xTbx合金均能形成非晶合金;隨著合金元素Tb含量的增加其玻璃形成能力逐漸增強,當x=8時,合金的玻璃形成能力最強,隨后當x=10時,有所下降.通過對Mg65Cu25Y10-xTbx合金系的電負性差與原子尺寸參數(shù)的計算,合理地解釋了產(chǎn)生這一現(xiàn)象的原因可能是由于Mg65Cu25Y10-xTbx合金的電負性差的變化所引起的;當x=6,8時,合金的玻璃形成能力較強,DTA圖顯示其成分可能屬于共晶點成分,同時通過計算得出此兩種非晶合金的λ值與由原子團族模型推導出的λ=0.18相差較大.

Abstract:采用浸漬法制備負載金屬Pd(其中金屬Pd含量0.6g/L)活性組分的金屬蜂窩載體催化劑,應(yīng)用于甲烷部分氧化制合成氣。實驗表明,焙燒溫度為950℃的催化劑較600℃的催化劑甲烷轉(zhuǎn)化率、CO和H2的選擇性更高,焙燒溫度為950℃的催化劑在反應(yīng)溫度800℃,GHSV=1×105ml/g·h條件下,甲烷轉(zhuǎn)化率為91%,CO和H2的選擇性分別達到90%和89%。用SEM與XPS對催化劑進行表征,結(jié)果表明,950℃焙燒催化劑并沒有出現(xiàn)明顯的燒結(jié)現(xiàn)象,且可能由于更多零價Pd的出現(xiàn),使得該催化劑的性能更好。由于金屬蜂窩載體優(yōu)良的導熱性,對950℃焙燒溫度制備的金屬蜂窩催化劑,催化劑床層的飛溫點溫度小于880℃,可以解決其它類型催化劑在甲烷部分氧化反應(yīng)中出現(xiàn)的飛溫問題,具有一定的工業(yè)化意義。

Abstract:The progresses in the ductility and toughness improvements for the structural materials of intermetallic compounds, especially the NiAl-based alloys, are reviewed in this paper. Owing to their intrinsic brittleness, the forming capability of these materials is poor. On the other hand, the advances in the fabrication process are also included in this paper since the materials properties are closely related to it.

Abstract:Electrospinning technique is playing an important role and has been regarded as one of the simplest and most effective techniques in the field of nanofibers fabrication. Various kinds of nanofibers have been prepared using this method, including polymers and inorganic nanofibers. In this paper, a comprehensive review is presented on the fabrication of inorganic nanofibers using electrospinning technique, including its mechanism, modification and effecting factors. In addition, the applications and future trends are presented and discussed for the inorganic nanofibers in this paper.

Abstract:The fatigue fracture resistance of FSW joints is one of the very important properties to assess the capability of FSW structure in practical application. The recent advances on the fatigue properties of FSW joints were summarized in details, which mainly included the test results of S-N curves, the relationship between fatigue crack growth rate da/dN and AK, the threshold value of stress intensity factor AKth and the fatigue crack growth behavior in corrosion environment. The influences of various factors on the fatigue behavior of FSW joints were analyzed and the existed problems for the fatigue assessment of FSW were proposed and discussed.