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Abstract:Methods of preparing foam materials, such as aluminium foam, titanium foam, silicon foam and lead foam, and how to control the composition and the porosity in order to prepare materials of different performances were presented. Excellent properties of foam materials, which were applied in auto industry, body in-planting material, optical material, micro-electronics, computer and lead-acid battery, etc., were emphatically introduced. Spacious market outlook was also previewed.

Abstract:The photocatalytic mechanism, catalogue and carrier of photocatalysts and its applications were described in this paper. According to their composition and structure, the photocatalysts are classified as simple oxide-type, nanometer sulfide, composite oxides, layer structure compound, AB2O4-type , complexes photocatalysts and so on. The development direction of photocatalyst is analyzed. The methods of improving the properties of photocatalysts and the factors influencing photocatalytic efficiency were discussed too.

Abstract:Gradient-dependent plasticity having characteristic length reflecting heterogeneity was used to deduce analytically non-uniform plastic strain in necked zone, and the external shape of the zone was described because the plastic strain and the plastic extension of the zone regardless of change of volume of the zone was calculated. In addition, the true stress was deduced because the minimum sectional area in the zone can be determined according to the external shape. The advantage of the present analytical results for true stress and true strain curve is that the related parameters have specific physical meanings, such as softening modulus describing brittleness, elastic modulus considering elasticity, characteristic length reflecting the heterogeneity, the gauge length involved in the present model to study the geometrical size effect. Comparisons of the existing experimental results for titanium and Ti-6Al-4V and the present analytical results were carried out and the new model considering microstructures and localized necking was verified. It is found that the brittleness and heterogeneity of Ti-6Al-4V are higher than those of CP titanium. The differences of the propagation velocity of the localized band in two kinds of materials are explained in terms of the different brittleness.

Abstract:用quantum Sutton-Chen多體勢(shì)對(duì)AgxCu1-x在冷卻速率為2×1012K/s凝固過(guò)程的模擬,發(fā)現(xiàn)AgxCu1-x在x=35～65范圍內(nèi)具有形成非晶的能力,特別是對(duì)應(yīng)于二元相圖共晶點(diǎn)的Ag60Cu40在凝固過(guò)程中二十面體和其它多面體結(jié)構(gòu)不僅數(shù)目大,而且還具有極為穩(wěn)定的遺傳性,而最容易得到非晶態(tài)合金.證實(shí)了合金化效應(yīng)對(duì)非晶態(tài)合金的形成傾向和穩(wěn)定性的關(guān)鍵作用.此外采用鍵對(duì)及原子多面體類型指數(shù)法對(duì)凝固過(guò)程中微觀結(jié)構(gòu)組態(tài)變化的分析,不但能說(shuō)明二十面體結(jié)構(gòu)在非晶態(tài)合金形成和穩(wěn)定性中所起的關(guān)鍵作用,又有助于對(duì)液態(tài)金屬的凝固過(guò)程、非晶態(tài)微觀結(jié)構(gòu)特征的深入理解.

Abstract:采用微分掃描式量熱法(DSC)、拉伸試驗(yàn)和彎曲試驗(yàn)研究了形變對(duì)Ti36Ni49Hf15高溫形狀記憶合金相變及雙程形狀記憶效應(yīng)的影響.結(jié)果表明,形變不影響合金的相變順序.在馬氏體狀態(tài)下變形時(shí),隨形變量的增加,Ti36Ni49Hf15合金的馬氏體相變溫度略有下降,逆馬氏體相變溫度上升.當(dāng)形變量一定時(shí),合金在馬氏體狀態(tài)下不同溫度變形,對(duì)合金的相變溫度沒(méi)有顯著影響.Ti36Ni49Hf15高溫記憶合金在馬氏體狀態(tài)下直接變形可以產(chǎn)生雙程形狀記憶效應(yīng),其雙程可逆應(yīng)變量隨形變量的增加而增加.在隨后的熱循環(huán)過(guò)程中,合金的雙程形狀記憶效應(yīng)在最初的幾次循環(huán)過(guò)程中迅速下降,而后隨循環(huán)次數(shù)的增加趨于穩(wěn)定.

Abstract:The air-exposed surfaces of sintered UC samples at room temperature were examined by X-ray photoelectron spectroscopy (XPS). Elemental depth profiles reveal that the surface of UC consists of a top layer of small amounts of UO2+ ; this very thin layer is x followed by a layer containing uranium dioxide, uranium monocarbide and free carbon and then bulk UC. The binding energy of U4f7/2 and C1s peaks of UC is found to be 378.2 eV and 282 eV, respectively. Quantitative analysis indicates that the C/U atomic ratio of clean UC surfaces is approximately 1?1, which is consistent with stoichiometric UC, but there exists small amounts of dissolved oxygen on sputter-cleaned UC surfaces. The oxidation mechanism of UC has been also discussed.

Abstract:采用直流磁控濺射法制備了SmCo/Cr,SmCo/CrTi 和SmCo/CrTi/Cr 系列薄膜。SmCo 薄膜的XRD 結(jié)果表明:在Cr 底層中添加Ti,得到的CrTi,CrTi/Cr 底層也是以(110)面擇優(yōu)取向的,但是和Cr 底層相比,衍射峰的位置由44.39°偏移到44.19°。薄膜的磁學(xué)性能由振動(dòng)樣品磁強(qiáng)計(jì)(VSM)測(cè)定,分析VSM 的測(cè)量結(jié)果可知,用CrTi 和CrTi/Cr做底層,SmCo 薄膜的矯頑力Hc、矩形比S、矯頑力矩形比S*的值都比Cr 底層的大,并且磁反轉(zhuǎn)體積V*的值比Cr 底層的小。SmCo 薄膜的δM(H)曲線說(shuō)明,Cr 做底層時(shí),薄膜晶粒間的相互作用為極化作用,CrTi,CrTi/Cr 做底層時(shí),薄膜晶粒間的相互作用為交換耦合相互作用。

Abstract:Dimension of injected parts reflects the quality of injection molded parts, and plays an important role in controlling defects and final dimension of parts during subsequent debonding and sintering. On the premise of same shrinkage in different directions during sintering, a mathematic model of controlling injected parts dimension and qualities by controlling the weight deviations of injected green parts, which is proved to be correct in the experiment is proposed.

Abstract:利用材料測(cè)試系統(tǒng)(MTS)、X-Ray衍射(XRD)和掃描電鏡(SEM)等手段研究了Nd基大塊金屬玻璃的變形行為和斷裂特征.Nd基大塊金屬玻璃樣品在室溫下是脆性斷裂,大約在500 K時(shí)變形模式從非均勻變形轉(zhuǎn)變?yōu)榫鶆蜃冃?在523 K以上表現(xiàn)出顯著的塑性變形.在5×10-4 m/s的應(yīng)變速率下,這種Nd基大塊金屬玻璃材料在523 K～600 K之間出現(xiàn)明顯的屈服應(yīng)力下降現(xiàn)象,隨后進(jìn)入1種穩(wěn)定的粘性流動(dòng)狀態(tài),而且這種屈服下降現(xiàn)象與溫度和應(yīng)變速率有關(guān).這種在過(guò)冷液相區(qū)的變形行為與其他大塊金屬玻璃變形特征相似.合金的這種塑性變形行為表明了其存在穩(wěn)定的過(guò)冷液相區(qū),同時(shí)對(duì)其變形行為的研究有助于進(jìn)一步了解Nd基大塊金屬玻璃的反常熱穩(wěn)定性.

Abstract:為了提高AZ91D 鎂合金的力學(xué)性能與阻尼性能,利用OM(光學(xué)金相顯微鏡)和XRD 分析了金屬型鑄造不同Ce 含量AZ91D 合金的顯微組織和相組成,測(cè)試了室溫力學(xué)性能,用懸臂梁技術(shù)測(cè)量了其阻尼性能。結(jié)果表明,AZ91D合金中加入一定量Ce 后生成的Al4Ce 相被推移到生長(zhǎng)界面,阻礙枝晶的自由生長(zhǎng),從而細(xì)化合金鑄態(tài)組織;Ce 能提高AZ91D 合金室溫抗拉強(qiáng)度,而對(duì)其屈服強(qiáng)度和延伸率影響不大,Ce 能提高合金的阻尼性能;AZ91D-0.7%Ce 合金晶粒細(xì)化效果佳,力學(xué)性能較理想,阻尼性能最高;合金的阻尼行為可用Granato-Lücke 理論來(lái)解釋。

Abstract:研究了微量Ti對(duì)Mg-9Al二元合金鑄造顯微組織和性能的影響.研究發(fā)現(xiàn),Ti的加入,使得Mg-9Al合金的塑性增加,明顯提高了Mg-9Al合金的抗腐蝕性能.分析結(jié)果表明,殘留Ti彌散分布在合金的基體中,Ti的加入有效降低了Fe的含量,一定程度上“凈化”了合金液,抑制了合金凝固時(shí)的異質(zhì)形核,使組織晶粒粗化.實(shí)驗(yàn)發(fā)現(xiàn),爐前加入0.12%的Ti(質(zhì)量分?jǐn)?shù),下同)時(shí),Mg-9Al合金的晶粒大小由145μm增大到188μm.隨著Ti的加入,Mg-9Al鑄造組織中β相的形態(tài),由半連續(xù)骨骼網(wǎng)狀改變?yōu)槎虠l狀和顆粒狀.當(dāng)爐前加入0.12%的Ti時(shí),Mg-9Al合金的綜合性能較佳.

Abstract:在Gleeble-1500D熱模擬實(shí)驗(yàn)機(jī)上對(duì)30ZrCp/W復(fù)合材料進(jìn)行高溫壓縮實(shí)驗(yàn),變形溫度和應(yīng)變速率分別為800℃～1 200℃和10-3 s^-1～1 s^-1,研究其高溫壓縮變形的流變應(yīng)力行為.研究表明:隨變形溫度升高,復(fù)合材料的流變應(yīng)力下降,在10-3s^-1和1200℃下,抗壓強(qiáng)度為948.7 MPa.在800℃下發(fā)生偽塑性變形,未達(dá)到預(yù)設(shè)變形量,真應(yīng)力-真應(yīng)變曲線上表現(xiàn)出的塑性為偽塑性,其是由微裂紋的萌生-鈍化引起的.隨變形溫度升高,復(fù)合材料發(fā)生動(dòng)態(tài)回復(fù)再結(jié)晶.隨應(yīng)變速率升高,真應(yīng)力-真應(yīng)變曲線形狀從“鋸齒”型向“平滑”型轉(zhuǎn)變.復(fù)合材料對(duì)應(yīng)變速率不敏感,隨應(yīng)變速率升高,復(fù)合材料的流變應(yīng)力略有升高.在800℃和1s^-1下,復(fù)合材料的抗壓強(qiáng)度為1176.9MPa.用Arrhenius方程描述復(fù)合材料在1000℃～1200℃的熱變形行為,變形激活能為811.4 kJ/mol.

Abstract:The atom structure models of two kinds of quasicrystal in Zr-base amorphous alloys were set up by using the conjugate structure model of quasicrystals. The effects of alloying elements on the crystallization behavior of Zr-base amorphous alloys were investigated by recursion method. The results show that two kinds of quasicrystal -Zr6Ni, Ni6Zr clusters are exist in Zr-base amorphous alloys, and alloying elements (Ag, Pt, Pd, Au) occupy the sites of Ni ( or Cu) in the quasicrystal phase, and that increase the interaction of neighbor atoms, which explains the fact of alloying elements (Ag, Pd, Pt, Au) promoting the stable growth of the quasicrystal phase.

Abstract:利用掃描電鏡(SEM)和鹽霧腐蝕試驗(yàn)等手段,研究了鎂合金在不同電導(dǎo)率溶液中微弧氧化處理生成陶瓷層的生長(zhǎng)規(guī)律及耐蝕性。結(jié)果表明:隨溶液電導(dǎo)率的增大,發(fā)生微弧氧化現(xiàn)象的起弧電壓減小,微弧氧化陶瓷層厚度表現(xiàn)出近似線性增長(zhǎng),陶瓷層表面微孔數(shù)目逐漸減少,微孔孔徑逐漸增大,陶瓷層內(nèi)顯微缺陷數(shù)量逐漸增多;陶瓷層的耐蝕性隨電導(dǎo)率的增大表現(xiàn)出先增后減的變化趨勢(shì),在溶液電導(dǎo)率為4 (?·m)-1～6 (?·m)-1 時(shí),陶瓷層的耐蝕性較好。

Abstract:闡述了指數(shù)曲線擬合方法和多項(xiàng)式擬合方法.分別用上述方法對(duì)52條卸載過(guò)程載荷-位移曲線進(jìn)行了擬合,其中多項(xiàng)式的最高次數(shù)分別選為2～6種.在NANOINDENTERⅡ上對(duì)13個(gè)試樣進(jìn)行了壓入實(shí)驗(yàn),試樣包括4個(gè)塊體材料試樣和9個(gè)膜/基材料試樣,最大壓入深度分為2組,即:一組為200 nm和500 nm,另一組為1 μm和2 μm.在每種壓入深度下,對(duì)每個(gè)試樣進(jìn)行兩次壓入.通過(guò)上述實(shí)驗(yàn),13個(gè)試樣可得到52條卸載過(guò)程載荷-位移曲線的數(shù)據(jù)文件.用所述擬合方法對(duì)所有卸載曲線進(jìn)行了擬合并得到相應(yīng)的擬合曲線參數(shù).用所得到的參數(shù)對(duì)試樣的硬度和彈性模量進(jìn)行了評(píng)定,對(duì)各種曲線擬合方法得到的載荷-位移擬合曲線與實(shí)測(cè)的載荷-位移曲線之間的關(guān)系進(jìn)行了分析.分析結(jié)果表明:在上述曲線擬合方法中,5次多項(xiàng)式曲線擬合是最佳的擬合方法,而指數(shù)曲線擬合是最差的擬合方法,曲線擬合方法對(duì)納米壓入法材料力學(xué)性能的測(cè)量結(jié)果產(chǎn)生較大的影響.

Abstract:Effect of specimen size on the residual stress distribution of Al2O3/Nb joint is studied using numerical analysis. It can be concluded that the difference of specimen size can greatly influence the stress distribution. When the height of the specimen increased, the residual stress did not change evidently, and the residual would not change any more with the height increased to some degree with the width of specimen increasing, the residual stress increased firstly. But when the width reached 25 mm, the residual stress decreased instead. In conclusion, increasing specimen size is beneficial to both residual stress decrease and structure design in practice.

Abstract:The contact angles of Ag on SnO2 with different CuO content were measured by the sessile drop method, and the morphology and composition of transition zone of the interfaces were analyzed by SEM and EPMA technique. The results show that the wettability of Ag on SnO2 is improved by increasing the CuO content. The contact angle of Ag/SnO2 decreases from 90oto 29o with 7% CuO content. When CuO dopant is added into SnO2, Ag liquid can infiltrate into MeO, and a little MeO diffuses into Ag zone. So the strong interfacial bonding is obtained.

Abstract:為了得到光電化學(xué)性能穩(wěn)定、光催化活性好、制備方法簡(jiǎn)便的TiO2光電極,采用涂覆法制備了納米TiO2薄膜光電極.XRD,SEM結(jié)果表明電極上涂覆的TiO2的晶型為銳鈦型,納米TiO2在電極表面分布均勻,薄膜厚度在10μm左右,且電極表面有一定的粗糙度.交流阻抗圖譜分析顯示TiO2電極在光照下能進(jìn)行光電化學(xué)反應(yīng).應(yīng)用于20mg/L苯酚溶液的降解中,結(jié)果表明,該電極光電催化降解性能優(yōu)于光催化降解性能,電場(chǎng)在降解過(guò)程中發(fā)揮了作用;對(duì)照態(tài)光氧化過(guò)程基本無(wú)化學(xué)反應(yīng)發(fā)生;暗態(tài)下電極上也無(wú)吸附現(xiàn)象;反應(yīng)后電極無(wú)剝落損傷.

Abstract:A contrastive experiment was conducted by using 4 key process parameters, i.e. concentration of sodium tungstate, current density, pH value and temperature that have greater influences on the electro deposition of Ni-W alloy nanocrystalline. Influences on the deposition rate, microhardness and surface of plating were studied respectively, which would provide basis for the preparation of Ni-W alloy nanocrystalline. At the same time, the plating of Ni-W alloy nanocrystalline was obtained, the size of which was10.09 nm.

Abstract:通過(guò)爆炸壓實(shí)燒結(jié)納米ITO粉末制備了ITO陶瓷靶材，結(jié)果表明爆炸沖擊壓實(shí)在靶材的后續(xù)燒結(jié)密實(shí)過(guò)程中起到了促進(jìn)作用，它與常規(guī)的加壓燒結(jié)相比，具有操作簡(jiǎn)單，設(shè)備要求低等很多優(yōu)點(diǎn)。經(jīng)過(guò)爆炸壓實(shí)的燒結(jié)靶材具有細(xì)小的晶體顆粒，比商業(yè)靶材的晶粒度小約1個(gè)數(shù)量級(jí)。

Abstract:MoO3 hydrosol was prepared by precipitation method. The effect factors on hydrosol were discussed systematically. TEM photos show that the MoO3 nanoparticles are spherical in shape, the size is about 60 nm, particle size distribution is in narrow range. ED images indicate that the MoO3 nanoparticles are polycrystalline structure. UV-VIS analysis show that the MoO3 nanoparticles hydrosol had good photochromic effect.

Abstract:Nanocrystalline La2O3 was prepared by sol-gel process using common La2O3, HNO3 and PEG. The decomposition process of the precursor powder and the calcened nanocrystalline La2O3 formed at the end were charactered with various techniques: TG-DTA, XRD and TEM and the effects of some factors such as pH value of the solution, stirring rate and the amount of the PEG in the solution on the particle size and morphology are investigated. The result shows that the nanocrystalline La2O3 can be obtained with particle diameter of 30 nm~50 nm under appropriate conditions.

Abstract:TiO2 codoped with antimony and chromium was prepared by coprecipation method. The characters of samples were measured by XRD, TEM, BET and DRS methods. TiO2 codoped with antimony and chromium shows intense absorption bands in the visible light region. Codoped samples are presented with enhanced performance over nondoped samples and TiO2 doped with only antimony.

Abstract:Metallic cementation treatment about Al, Zn elements on ZM5 magnesium alloy was conducted by solid diffusion.It was shown that the solid diffusion layer was mainly composed of Mg-Al-Zn intermetallic compounds and Mg-Al-Zn solid solution transition zone that had more Zn and Al elements than standard ZM5 magnesium substrate did. The test indicated that the microhardness values of Mg-Al-Zn intermetallic compounds were much higher than that of the substrate, and this would greatly contribute to the enhancement of wear resistance. The diffusion alloying layer was an effective corrosion barrier to decrease the corrosion rate for ZM5 magnesium alloy when exposed to 3.0% NaCl solutions.

Abstract:采用室溫固相化學(xué)反應(yīng)前驅(qū)體法合成了亞微米級(jí)的(La,Ce,Tb)PO4綠色熒光粉.利用熱重-差示熱分析(TG-DTA)、X射線衍射(XRD)、掃描電鏡(SEM)、透射電鏡(TEM)等實(shí)驗(yàn)技術(shù),研究了熒光粉的形成過(guò)程,并對(duì)粉體尺寸、形貌及發(fā)光性能進(jìn)行研究.結(jié)果表明:將前驅(qū)體在900℃煅燒后,產(chǎn)物為單斜晶系、獨(dú)居石結(jié)構(gòu)的正磷酸鹽.粉末為亞微米級(jí)的球形顆粒.在272 nm紫外線激發(fā)下發(fā)綠色熒光,發(fā)射主峰在548 nm.同時(shí)表明:用室溫固相化學(xué)反應(yīng)前驅(qū)體法合成的(La,Ce,Tb)PO4是1種性能優(yōu)良的熒光粉.

Abstract:采用機(jī)械合金化、冷壓與熱擠壓法制備了Al-15%Pb-4%Si-1%Sn-1.5%Cu(質(zhì)量分?jǐn)?shù))軸瓦合金.實(shí)驗(yàn)結(jié)果表明,合金中Pb晶粒為納米晶,Al以2種形態(tài)存在于合金體系中,一部分為亞微米晶體,另一部分為非晶相.合金的抗壓強(qiáng)度和硬度值都隨熱擠壓溫度的升高而降低;熱擠壓溫度為400℃時(shí),合金的抗壓強(qiáng)度σbe和抗壓屈服強(qiáng)度σ0.2分別為610 MPa和440 MPa;其HV值達(dá)到1 820 MPa,高于采用其它方法制備的Al-Pb系軸瓦合金的值.

Abstract:In order to search a new process of fabricating TiAl intermetallic compounds with favorable combination of properties, this paper investigated the microstructure and thermal stability of Al-10wt.%Ti powders synthesized by mechanical milling. The experimental results show that Al, Ti particle and grain size decrease rapidly with the increase of milling time, and that the more milling time, the more energy stored in the composite powders. Consequently, the activation energy of the reaction for Al-Ti intermetallics decreases obviously. It is mechanical milling that causes a large number of crystal defects such as dislocations, vacancies, stacking fault and grain boundaries, hence raise the internal energy and the diffusivity. The final equilibrium phase of Al-10wt.%Ti powder which was sintered is DO22-Al3Ti.

Abstract:Metastable single phase with CaCu5 type structure for Co free over-stoichiometric La(NiMn)6 alloys were obtained by non-equilibrium processing of melt spinning. The crystal structure and electrochemical properties were investigated comparatively. The XRD results show that the La(NiMn)6 alloys prepared by melt spinning, in comparison with the as-cast alloys, present a single phase with CaCu5 type. The crystal lattice constants a and c exhibit a anisotropic change. With the increase of cooling rate, the a axis decreases and c axis and ratio of c/a value increase. The electrochemical analyses show that when cooling rate increases from 20 m/s to 50 m/s, the MH electrodes discharge capacity reach 277 mAh/g~256 mAh/g and the capacity retention is 63%~97.8% after 100 cycling number. The alloys prepared by melt spinning show a good cycling stability, but a lower discharge capacity and worse activation kinetics than that of the as-cast alloys.

Abstract:采用磁控濺射方法制備金屬銻薄膜,并把它作為鋰離子二次電池負(fù)極進(jìn)行研究。研究發(fā)現(xiàn),通過(guò)磁控濺射比較容易控制條件得到符合條件的銻薄膜,并且薄膜銻有較平的吸放鋰平臺(tái)。另外,不同厚度對(duì)銻薄膜的吸放鋰性能有較顯著的影響,較薄的銻薄膜有著更好的電化學(xué)吸放鋰性能,經(jīng)過(guò)15 個(gè)循環(huán)后其脫鋰容量仍保持在400 mAh·g-1 以上。

Abstract:用伏安電荷容量表征了聚合前驅(qū)體法制備的Ti/TiO2電極的熱分解溫度和熱分解時(shí)間對(duì)電極電催化活性的影響,用XRD,ESEM,TEM對(duì)所制電極的表面結(jié)構(gòu)、形貌及TiO2的粒徑進(jìn)行了表征.實(shí)驗(yàn)結(jié)果表明:熱分解溫度和熱分解時(shí)間對(duì)Ti/TiO2電極的伏安電荷容量有顯著的影響,在熱分解溫度低于500℃時(shí),延長(zhǎng)熱分解時(shí)間有利于提高電極的電催化活性.熱分解反應(yīng)溫度大于500℃后,增長(zhǎng)熱分解時(shí)間,電極的電催化活性減小.不同熱分解溫度和熱分解時(shí)間下所形成的不同的電極表面結(jié)構(gòu)和形貌影響了Ti/TiO2電極的電催化活性.

Abstract:Zr-Si-N diffusion barrier films were deposited by reactive magnetron sputtering with different negative bias. The results reveal that the Si content and resistivity of the Zr-Si-N films decrease as negative bias increases. The crystalline phase increases with the increase of negative bias. The thermal stability of Zr-Si-N diffusion barrier was so good that Zr-Si-N diffusion barrier can effectively prevent from the diffusion of Cu.

Abstract:為了改善空氣擴(kuò)散電極的電催化性能,提高鋅空氣電池的放電電流,采用溶膠-凝膠法制備了分子式為L(zhǎng)a1-xSrxMnO3的鋅空氣電池用電催化劑.通過(guò)X射線衍射(XRD)、穩(wěn)態(tài)電流-電壓極化曲線等方法研究了La1-xSrxMnO3催化劑的結(jié)構(gòu)與電催化性能,并將其作為鋅空氣電池催化劑裝配成AA型鋅空氣電池進(jìn)行恒流放電測(cè)試.研究結(jié)果表明,當(dāng)分子式中的x=0.3、熱處理溫度為700℃時(shí),所合成催化劑La0.7Sr0.3MnO3具有最優(yōu)的電催化活性;XRD的分析證實(shí),該催化劑的結(jié)構(gòu)為完美的鈣鈦礦型晶體結(jié)構(gòu);分別以La0.7Sr0.3MnO3和LaMnO3為催化劑的AA型鋅空氣電池的放電容量分別為4800mAh和4200mAh,前者比后者的放電比能量有顯著的提高.該催化劑的研制成功將有助于加快鋅空氣電池的實(shí)用化進(jìn)程.

Abstract:采用溶膠凝膠(Sol-Gel)和兩步氫還原及燒結(jié)法成功制備了(2%～5%),質(zhì)量分?jǐn)?shù),下同)La2O3-Mo陰極粉末和燒結(jié)體,借助于XRD,SEM等手段對(duì)材料成分及微觀結(jié)構(gòu)進(jìn)行分析.結(jié)果顯示在粉末和燒結(jié)體中稀土元素La以氧化物形式存在,La2O3粒子大小為100nm,彌散分布在燒結(jié)體基體中.熱發(fā)射測(cè)試結(jié)果表明1400℃時(shí),零場(chǎng)發(fā)射電流達(dá)到J0=6A/cm^2.暴露大氣48h后,再經(jīng)過(guò)1350℃激活,發(fā)射性能得到全面恢復(fù).

Abstract:商業(yè)用純鈦在空氣爐中700℃～900℃,1h～4h進(jìn)行熱氧化處理,得到由氧化層和滲氧層構(gòu)成的表面結(jié)構(gòu).通過(guò)金相觀察、顯微硬度測(cè)試、X射線衍射(XRD)及掃描電鏡(SEM)分析,研究了滲氧層的結(jié)構(gòu)和性能.結(jié)果表明,經(jīng)一定溫度及時(shí)間處理,試樣滲氧層被一條連續(xù)的界線分為內(nèi)滲氧層和外滲氧層,在光學(xué)顯微鏡下觀察,內(nèi)外兩層滲氧層形貌無(wú)差別,但在掃描電鏡下觀察可發(fā)現(xiàn)在較高溫度形成的外滲氧層較疏松,內(nèi)滲氧層則仍致密.隨著熱處理溫度的升高、時(shí)間的延長(zhǎng),滲氧層厚度和含氧量增加,晶格常數(shù)c伸長(zhǎng),表面硬度顯著增大.

Abstract:Nano-metal nickel powder is prepared by liberty arc in which fusible hydrogen is joined as cathode shoot. It is found that the influence of working pressure do not followed the classical rules. Hydrogen is a key factor to improve the productive efficiency of nano metal powder. The mini-hydrogen bubble in fusible metal can lead to the vacuum evaporating of Nickel, so the powder productivity is proportional to the hydrogen pressure. The molecular evaporating mechanism of hydrogen in Ni bubble is presented.

Abstract:采用Gleeble-1500D熱模擬機(jī),在電場(chǎng)和大熱流密度作用下,研究壓坯密度對(duì)55%(Ti C)-45?(質(zhì)量分?jǐn)?shù))粉末壓坯低溫燃燒合成過(guò)程的影響.結(jié)果表明:當(dāng)壓坯密度在68%～78%范圍內(nèi),體系的點(diǎn)火溫度在340℃～650℃之間;隨壓坯密度提高,體系點(diǎn)火溫度降低,點(diǎn)火延遲時(shí)間縮短,所達(dá)到的最高溫度也降低.同時(shí),合成產(chǎn)物的XRD結(jié)果表明:較低密度壓坯的合成反應(yīng)進(jìn)行完全,而過(guò)高的壓坯密度會(huì)導(dǎo)致合成反應(yīng)的不完全性.

Abstract:研究了1種新型的納米AgSnO2觸頭材料.通過(guò)采用摻雜、SnO2粒子的納米化及化學(xué)鍍的方法,改善了氧化物和銀的浸潤(rùn)性,從而提高了觸頭材料的導(dǎo)電性、機(jī)械強(qiáng)度和加工性能.通過(guò)機(jī)械混合法和溶膠凝膠法2種工藝的對(duì)比,證明用機(jī)械混合法在SnO2中摻雜TiO2,反而使電導(dǎo)率升高;用溶膠凝膠法在SnO2中摻雜TiO2,Ti4 能夠很好的進(jìn)入SnO2的晶格,能夠明顯改善觸頭的電性能.微觀組織分析表明:納米觸頭中SnO2的分布明顯的比非納米觸頭中SnO2分布的要均勻,從而可以避免因SnO2的富集導(dǎo)致電導(dǎo)率降低,提高AgSnO2觸頭的電性能和電壽命.

Abstract:用放電等離子燒結(jié)技術(shù)將WO3和炭黑的混合粉原位合成為致密的WC塊體.研究了合成工藝和配碳量對(duì)塊體的物相、致密度和顯微組織的影響,結(jié)果表明:在860℃～1060℃溫度范圍內(nèi),炭能快速地將WO3還原成W,同時(shí)發(fā)生碳化反應(yīng),溫度繼續(xù)升高發(fā)生燒結(jié).含碳量低時(shí),塊體中有雜相W或W2C,含碳量合適時(shí),塊體的物相為純WC,致密度達(dá)到WC的理論密度,晶粒在500nm左右.

Abstract:Sintering is one of the most important steps for powder metallurgy (PM). In order to observe the sintering process directly, a high temperature optical microscope (HTOM) was used to in-situ investigate the Al and Mg binary alloy system with a weight ratio of 9:1. A typical physical evolving character was found in this system. The melting process of magnesium particles is not synchronous, first from the particle border, then in the grain boundary, and last into the whole magnesium particle. When sintering temperature is above a critical temperature Tc, the magnesium particle melts in a very short time, and the sintering rate is accelerated with the increasing of the cold compact density. These experiment results afford a direct reference to the sintering routine optimization.

Abstract:Research about the 91tungsten alloy deformed by hydrostatic extrusion is carried out. The relations between the microstructures, mechanical properties of the 91tungsten alloy after deformation and the deformation amount were studied. The results show that the ratio of the long-short axis of tungsten particles and the strength of tungsten alloys increase along with the increase of the deformation amount, the valid contiguity of tungsten particles and the elongation ratio and contraction ratio of area of tungsten alloys decrease along with the increase of the deformation amount. Both the increment and the decrement become smaller and smaller along with the increase of the hydrostatic extrusion deformation amount.

Abstract:根據(jù)合金相圖的基本原理,分析了Au-Ag-Si系相圖,研制出熔化溫度在400℃～500℃的共晶釬料合金.通過(guò)釬料合金與Ni板的潤(rùn)濕性測(cè)試和潤(rùn)濕后界面的微觀組織分析.結(jié)果表明:Au-Ag-Si系釬料對(duì)于純Ni具有良好的漫流性和潤(rùn)濕性,在450℃～500℃范圍內(nèi),可以對(duì)Ni板進(jìn)行釬焊.

Abstract:研究激光退火對(duì)Inconel718時(shí)效合金的顯微組織和硬度的影響.一臺(tái)2.5kW的CO2激光機(jī)被用來(lái)照射試樣的表面.在激光能作用下,試樣表面層被加熱后空冷.通過(guò)控制激光工藝參數(shù),在表面不發(fā)生熔化的前提下,能夠使一定厚度表面層內(nèi)的硬度降低到標(biāo)準(zhǔn)退火合金的水平,而不影響試樣內(nèi)部母材的硬度.顯微組織觀察顯示表面層的基體強(qiáng)化相(γ″和γ‘)在激光照射過(guò)程中被固溶,而其它二次相沒(méi)有變化.γ″和γ‘的固溶被確定是表面層硬度下降的原因.在其它試驗(yàn)條件不變時(shí),確立了退火層生成時(shí)由激光散焦距離和掃描速度描述的工藝參數(shù)范圍.