- Volume 36,Issue 6,2007 Table of Contents
>材料科學(xué)
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Lü Xianghong , Yang Yanqing , Ma Zhijun , Luo Xian , Huang Bin , Chen Yan
2007, 36(6):941-948.
Abstract:采用三元體系半無限擴(kuò)散偶的高斯方法，求解了SiC／Ti6A14V復(fù)合材料界面反應(yīng)層中相關(guān)元素的擴(kuò)散系數(shù)，計(jì)算的濃度分布和實(shí)測值一致。碳原子通過反應(yīng)層的擴(kuò)散服從間隙擴(kuò)散機(jī)制，硅原子的擴(kuò)散為空位擴(kuò)散機(jī)制。由于碳擴(kuò)散的振動能最低并且躍遷距離最短，而供硅擴(kuò)散的空位不足，碳和硅在反應(yīng)產(chǎn)物TiC，中具有最小的內(nèi)稟擴(kuò)散系數(shù)，分別為8．9403×10^-16和4．7747×10^-16·m^2·s^-1。研究表明，在SiC／Ti6A14V復(fù)合材料界面反應(yīng)的過程中，反應(yīng)元素通過反應(yīng)層TiCx的擴(kuò)散是一個主要的控制步驟。
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2007, 36(6):941-948.
Abstract:采用三元體系半無限擴(kuò)散偶的高斯方法,求解了SiC/Ti6AL4V復(fù)合材料界面反應(yīng)層中相關(guān)元素的擴(kuò)散系數(shù),計(jì)算的濃度分布和實(shí)測值一致.碳原子通過反應(yīng)層的擴(kuò)散服從間隙擴(kuò)散機(jī)制,硅原子的擴(kuò)散為空位擴(kuò)散機(jī)制.由于碳擴(kuò)散的振動能最低并且躍遷距離最短,而供硅擴(kuò)散的空位不足,碳和硅在反應(yīng)產(chǎn)物TiCx中具有最小的內(nèi)稟擴(kuò)散系數(shù),分別為8.9403×10-16和4.7747×10-16 m2·s-1.研究表明,在SiC/Ti6AL4V復(fù)合材料界面反應(yīng)的過程中,反應(yīng)元素通過反應(yīng)層TiCx的擴(kuò)散是一個主要的控制步驟.
>材料科學(xué)
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Jiang Na , Li Jinfeng , Zheng Ziqiao , Ren Wenda , Han Dongfeng Co. Ltd , Chongqing , China)
2007, 36(6):949-953.
Abstract:采用G1eeble-1500熱模擬實(shí)驗(yàn)機(jī)，對2195鋁鋰合金變形溫度為360～520℃，應(yīng)變速率為0．001-1．0s^-1的單道次熱壓縮及變形溫度為320℃和360℃，應(yīng)變速率為0．1s^-1，道次間隔時間30-180s的雙道次熱壓縮的流變應(yīng)力及靜態(tài)軟化規(guī)律進(jìn)行了模擬研究。通過對冪指數(shù)應(yīng)力函數(shù)中系數(shù)A和β與應(yīng)變關(guān)系的分析，以及采用平均軟化法考慮前一道次變形的殘余應(yīng)變對后一道次變形的影響，建立了2195鋁鋰合金多道次熱變形的流變應(yīng)力方程。
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Zhang Peixin , Wen Yanxuan , Liu Jianhong , Xu Qiming , Ren Xiangzhong , Zhang Qianling , Luo Zhongkuan
2007, 36(6):954-958.
Abstract:The chemical co-precipitation method was used to synthesize LiFePO4 by doping with Mg2+,Al3+,Ti4+,V5+,and Ni 2+,then the specific charge/discharge capacity of LiFePO4 was measured by stable-current charge/discharge method and the particle structure was examined by X-ray diffraction and Rietveld method. The results indicate that a small amount of metal ion doping can improve the discharge capacity of LiFePO4 to above 120 mAh/g at high current and keeping the capacity over 80% after 20 cycles when the charge/discharge rate is at 2C for Li1-xTixFePO4,Li1-xVxFePO4 and Li1-xNixFePO4,mainly due to the metal ion dopings in the form of solid solution and occupying the position of Lithium. The metal ion dopings change the distance and position between atoms in grains,resulting in the contraction of unit cells,the increase of average distance between Li-O atoms and the disengagement of Lithium ions.
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Wang Yuehui , Zhou Ji , Wang Ting
2007, 36(6):959-962.
Abstract:采用傳統(tǒng)固相反應(yīng)法對水熱BaTiO3粉體進(jìn)行La2O3和Nb2O5雙施主復(fù)合摻雜，研究（Bal-xLa2x/3）（Til-xNb4x/5）O3陶瓷顯微結(jié)構(gòu)特征。結(jié)果表明：隨著X的增大，晶體結(jié)構(gòu)逐漸由四方相轉(zhuǎn)為立方相。當(dāng)x≤0．03時，La^3＋、Nb^5＋固溶進(jìn)入BaTiO3晶格形成單一的鈣鈦礦相；當(dāng)x=0．05時，出現(xiàn)Ba6Til7O40富鈦第二相；當(dāng)x≥0．2時，出現(xiàn)Ba-Ti-La-Nb固溶組分的第二相，說明旆主摻雜固溶極限x〈0．2。當(dāng)x=0．001時，瓷體具有半導(dǎo)化特征，晶粒尺寸為8～10μm；當(dāng)x≥0．004時，瓷體開始呈現(xiàn)絕緣性，旆主離子表現(xiàn)出明顯的抑制晶粒生長作用，隨著X增加，晶粒尺寸由10μm（x=0．004）下降至0．5μm（x=0．3）。TEM和EDS分析表明，La^3＋、Nb^5＋雙旆主復(fù)合摻雜，La^3＋提高了Nb^5＋的擴(kuò)散固溶能力，相互協(xié)同作用使摻雜離子在BaTiO3中分布更均勻。
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Li Hui , Zhao Yongqing , Qu Henglei , Zeng Weidong
2007, 36(6):963-967.
Abstract:利用OM（光學(xué)金相）、SEM對損傷容限TC4-DT合金雙態(tài)組織中的疲勞裂紋擴(kuò)展行為進(jìn)行研究。結(jié)果表明：裂紋擴(kuò)展遇到初生口相時，既能以繞過初生口相的方式擴(kuò)展，又能直接切過初生口相向前擴(kuò)展；預(yù)裂區(qū)和快速擴(kuò)展區(qū)主要是以微區(qū)解理斷裂為主，穩(wěn)態(tài)擴(kuò)展區(qū)主要是以疲勞條帶擴(kuò)展機(jī)制為主，同時也存在微區(qū)解理斷裂機(jī)制。
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Zhang Xin , Zhang Jiuxing , Lu Qingmei , Wei Qun , Liu Danmin , Liu Yanqin
2007, 36(6):968-972.
Abstract:采用放電等離子燒結(jié)（sps）技術(shù)在800～1000K溫度范圍內(nèi)，原位反應(yīng)合成了以ce，La作為填充原子及Ni，F(xiàn)e作為置換原子的填充式方鈷礦化合物REy（Fe／Ni）xCO4xsb12（x=0～1．0，y=0～0．4）。系統(tǒng)研究了填充原子的種類、填充方式以及置換原子的種類對晶格熱導(dǎo)率及熱電性能的影響。結(jié)果表明，在Co位置上Fe或Ni的置換，能顯著降低其晶格熱導(dǎo)率，與Fe相比，Ni對晶格熱導(dǎo)率的影響更顯著。在Skutterudite結(jié)構(gòu)sb組成的二十面體空洞填充ce，La原子可以顯著降低其晶格熱導(dǎo)率，在填充分?jǐn)?shù)相同時，兩種稀土原子復(fù)合填充較單一原子填充更能有效降低晶格熱導(dǎo)率。電導(dǎo)率隨ce，La填充分?jǐn)?shù)的增加而降低，Seebeck系數(shù)隨填充分?jǐn)?shù)的增加而升高。填充分?jǐn)?shù)為0．3的ce0.1La0.2FeCo3Sb12化合物具有最低的晶格熱導(dǎo)率和最大的zT值，在800K時達(dá)0．6左右。
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Zhang Deming , Chen Guiqing , Meng Songhe , Qu Wei , Han Jiecai
2007, 36(6):973-976.
Abstract:采用電子束物理氣相沉積（EB-PVD）技術(shù)，成功制備了尺寸為150mm×100mm的TiAl基合金薄板，并利用光學(xué)顯微鏡（OM）、掃描電子顯微鏡（SEM）和x射線衍射（XRD）等測試手段，對真空退火或熱壓前后試樣的顯微形貌、物相組成等進(jìn)行了分析。結(jié)果表明，蒸鍍態(tài)TiAl基合金薄板由 γ相、α2相和ι相組成，成分呈梯度變化，內(nèi)部自然分層，顯微組織結(jié)構(gòu)為柱狀晶；經(jīng)1000℃，16h的真空退火處理后，柱狀晶和τ相消失，α2相含量顯著減少，成分趨于均勻化；而經(jīng)1250℃，1h的真空熱壓處理后，材料致密度得到明顯提高。TiAl基合金薄板經(jīng)真空退火或熱壓處理前后，斷裂方式由沿晶斷裂轉(zhuǎn)變?yōu)榻饫頂嗔押脱鼐嗔训幕旌蠑嗔逊绞健?/p>
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Wang Qingyang , Zhang Pingxiang , Li Jinsan , Yan Guo , Lu Yafen
2007, 36(6):977-980.
Abstract:采用低碳鋼作為外包套材料，通過原位法粉末裝管工藝（in-situPIT）制備出高密度Ti、zr摻雜的MgB2／Fe／Cu線材。將線材短樣在氬氣保護(hù)條件下，于650-800℃燒結(jié)2～5h。MgB2線材的微結(jié)構(gòu)分析顯示，通過該工藝制備的MgB2／Fe／Cu線材比MgB2塊材具有更好的晶粒連結(jié)性和更高的致密度。采用標(biāo)準(zhǔn)的四引線法，在4．2K，0～8T的磁場下測試線材的I臨界電流密度。測試結(jié)果顯示，800℃燒結(jié)的Mg0.9Zr0.1B2／Fe／Cu線材獲得了最高的臨界電流密度。
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Xiao Lixia , Yuan Songliu , Wang Yongqiang , Yin Shiyan
2007, 36(6):981-984.
Abstract:用固相反應(yīng)法制備了（1-x）La2／3Ca1／3MnO3/xcr2O3（x為摩爾分?jǐn)?shù)）復(fù)合樣品，實(shí)驗(yàn)研究了在外加0～3T的磁場下，Cr203含量對該復(fù)合樣品的電輸運(yùn)性質(zhì)及磁電阻的影響。結(jié)果發(fā)現(xiàn)隨著Cr2O3含量的增加，金屬．絕緣體（M-I）轉(zhuǎn)變溫度耳急劇降低，并且當(dāng)Cr2O3，含量x〉0．1時此轉(zhuǎn)變消失。與此同時，電阻率隨其含量增加而快速增大，特別的是在樣品中觀察到了較寬溫度范圍內(nèi)顯著增強(qiáng)了的磁電阻。這種結(jié)果的出現(xiàn)可能與Cr2O3有關(guān)的新相偏析在La2／3Ca1／3MnO3（LCMO）晶界和顆粒界面有關(guān)。
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Study on Electronic Structure and Microdefects by Positron Annihilation Spectroscopy for NiTi Alloys
Hu Yifeng , Deng Wen , Chen Zhenying
2007, 36(6):985-988.
Abstract:Doppler-broading spectrum of positron annihilation radiation have been measured by using 2-detector coincidence technique for pure metals of Si, Ni, Ti and NiTi alloys with five different chemical compositions. The W parameters of NiTi alloys are calculated. The experimental results show that some 3d electrons are localized to form covalent bonds when Ni and Ti atoms aggregate to form NiTi alloy, decreasing the free electrons in metal bonds. The covalent bonds and metal bonds coexist in NiTi alloy. The Ni-49at%Ti alloy has the biggest W parameter, indicating that the quantity of defects is least in this component alloy. This may be the reason why the Ni-49at%Ti alloy has the best shape memory effect.
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薛蕾 , 陳靜 , 林鑫 , 王維 , 呂曉衛(wèi) , 黃衛(wèi)東
2007, 36(6):989-993.
Abstract:針對Ti-6Al-4V合金在加工和服役過程中的損傷特點(diǎn),對Ti-6Al-4V合金鍛件的3種典型誤加工缺陷——槽缺陷、面缺陷和體缺陷進(jìn)行了激光快速修復(fù)研究。激光修復(fù)區(qū)與鍛件基體形成致密冶金結(jié)合,Al、V合金元素由鍛件基體到激光修復(fù)區(qū)均勻分布,無宏觀偏析。激光修復(fù)區(qū)組織為粗大原始β晶粒內(nèi)分布細(xì)長的α針及編織細(xì)密的α+β板條組織,呈現(xiàn)典型的魏氏結(jié)構(gòu),熱影響區(qū)組織從鍛件的等軸α+轉(zhuǎn)變β組織逐步過渡到魏氏(α+β)組織。對預(yù)制有3種類型缺陷的激光修復(fù)試樣進(jìn)行室溫靜載拉伸試驗(yàn)和硬度測試,結(jié)果表明修復(fù)試樣的拉伸性能達(dá)到鍛件標(biāo)準(zhǔn)(HB5224-1982)。激光修復(fù)試樣的硬度和強(qiáng)度高于鍛件基體,而塑性則低于鍛件基體。因此,激光修復(fù)區(qū)和鍛件基體可看作是一種“強(qiáng)+弱”的組合,這與二者的顯微組織是相對應(yīng)的。
>材料科學(xué)
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Xue Lei , Chen Jing , Lin Xin , Wang Wei , LU Xiaowei , Huang Weidong
2007, 36(6):989-993.
Abstract:針對Ti-6A1-4V合金在加工和服役過程中的損傷特點(diǎn)，對Ti-6A1-4V合金鍛件的3種典型誤加工缺陷——槽缺陷、面缺陷和體缺陷進(jìn)行了激光快速修復(fù)研究。激光修復(fù)區(qū)與鍛件基體形成致密冶金結(jié)合，Al、V合金元素由鍛件基體到激光修復(fù)區(qū)均勻分布，無宏觀偏析。激光修復(fù)區(qū)組織為粗大原始∥晶粒內(nèi)分布細(xì)長的α針及編織細(xì)密的a＋β板條組織，呈現(xiàn)典型的魏氏結(jié)構(gòu)，熱影響區(qū)組織從鍛件的等軸α＋轉(zhuǎn)變β組織逐步過渡到魏氏（a＋β）組織。對預(yù)制有3種類型缺陷的激光修復(fù)試樣進(jìn)行室溫靜載拉伸試驗(yàn)和硬度測試，結(jié)果表明修復(fù)試樣的拉伸性能達(dá)到鍛件標(biāo)準(zhǔn)（HB5224-1982）。激光修復(fù)試樣的硬度和強(qiáng)度高于鍛件基體，而塑性則低于鍛件基體。因此，激光修復(fù)區(qū)和鍛件基體可看作是一種“強(qiáng)＋弱”的組合，這與二者的顯微組織是相對應(yīng)的。
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Wang Wenjun , Lin Junpin , Wang Yanli , Chen Guoliang
2007, 36(6):994-997.
Abstract:The static isothermal corrosions of Ti-50A1 and Ti-45A1-8Nb alloys in liquid zinc were studied and their positron lifetime spectrums were measured. The densities of free electrons of the bulk and microdefects in these alloys were calculated by using the positron lifetime parameters. It is found that the density of free electrons is lower in the bulk TiAl alloy than in Ti or Al matrix due to the localization and aggregation of some valence electrons in Ti and Al atoms to form TiAl alloy with a mixture bond of metallic bond and covalent bond. The large open defects occurs in the grain boundary of TiAl alloy and the bonding strength of grain boundary is weak due to the low density of free electrons. Then the densities of free electrons in the bulk and the grain boundary will simultaneously increase due to the great decrease of dissolution rate in liquid zinc as the TiAl alloy is alloyed with Nb
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Li Minggao , Sun Daqian , Qiu Xiaoming , Sun Dexin , Yin Shiqiang
2007, 36(6):998-1001.
Abstract:采用透射電鏡和拉伸試驗(yàn)研究了溫度對醫(yī)用TiNi形狀記憶合金（TiNiSMA）絲微觀組織和力學(xué)性能的影響。結(jié)果表明，TiNiSMA微觀組織和力學(xué)性能對溫度變化極為敏感。對TiNiSMA進(jìn)行短時加熱處理，隨加熱溫度升高，TiNiSMA組織由冷拔態(tài)纖維狀組織逐漸轉(zhuǎn)變?yōu)榘鍡l狀馬氏體群組織，且組織粗化，位錯密度下降：TiNiSMA抗拉強(qiáng)度和超彈性能下降，塑性增加，當(dāng)加熱溫度超過400℃時這種趨勢更加顯著。
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Jiang Longtao , Wu Gaohui , Norio Kouno , Hideo Saito
2007, 36(6):1002-1004.
Abstract:選用0．15μm和5μm的Al2O3顆粒，采用擠壓鑄造法制備了體積分?jǐn)?shù)為40％的鋁基復(fù)合材料。利用選區(qū)電子衍射和高分辨電子顯微技術(shù)研究了Al2O3P／1070Al界面附近基體的顯微組織。結(jié)果表明，復(fù)合材料增強(qiáng)體顆粒為5μm時，基體存在大量的Eh熱錯配應(yīng)力引發(fā)的位錯，顆粒粒徑為0．15μm時，基體表現(xiàn)為近無位錯的組織特征，其缺陷形式為1～5nm的“微畸變區(qū)”，這主要是由于粒徑小、分布彌散，微區(qū)應(yīng)力均勻所致。
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Song Min , Chen Kanghua , Huang Langping
2007, 36(6):1005-1007.
Abstract:The effects of Mg element on the distribution of dislocations in Al-Cu-Mg alloy have been investigated. It has been shown that the interaction between Mg and Cu atoms was decreased since the concentration of Cu in Al matrix decreases due to the formation of Al2Cu precipitates during deformation and aging. The Mg element blocks the distributed glide of dislocations and thus inhibits the formation of cell structures due to the large atom radius, producing high aberrance energy and internal friction in Al matrix. Compared with the cell structures in typical metals and alloys with high stacking-fault energy, the dislocations in Al-Cu-Mg alloy are quasi-uniformly distributed and can decrease the free energy, named as the Taylor lattice distribution.
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2007, 36(6):1008-1011.
Abstract:A special furnace was designed and applied to produce an external electrical field up to 4 kV/cm and to study the wettability between copper and tungsten. The results showed that chromium can significantly reduce the wetting angle between copper and tungsten, so benefit to Cu-W infiltration system. The electrical field can also reduce the wetting angle, but not so stronger by comparing with chromium in the experimental electrical field range.
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Wen Shunda , Chen Liqiang , Gong Shengkai , Xu Huibin , Peng Hui
2007, 36(6):1012-1015.
Abstract:Tension-compression tests at high temperature were carried out on the specimens made of Ni based superalloys (DZ125 alloy) coated with bond coating (NiCoCrAlY) and zirconia ceramic coating by electron beam-physical vapor deposition(EB-PVD). Failure of the thermal barrier coatings (TBC) was investigated. The test results show that the failure of TBCs occurred from the initiation and expansion of fracture in TGO,differing from under thermal loading alone. There are two kinds of fracture cracks: initiating from the TGO/bond coat interface and the bond coat/diffusion coat,respectively,resulting in the failure of specimens at last. From the simulation results by finite element analysis (FE),it can be conclude that there are abrupt changes of stress state and value near the interfaces of TGO/TBC and TGO/bond coats. The abrupt change of radial stress would result in the failure of TBCs from the spallation of interface. The abrupt change of axial stress would accelerate the extension of the microcracks perpendicular to the interface,resulting in the rupture of specimens.
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Liu Hongtao , Sang Wenbin , Yuan Zheng , Min Jiahua , Zhan Feng
2007, 36(6):1016-1019.
Abstract:采用有限元方法，對晶體結(jié)晶結(jié)束位置處的晶體內(nèi)部熱應(yīng)力分布進(jìn)行了數(shù)值模擬，結(jié)果表明：晶體在石英安瓿內(nèi)壁附近，變徑處以及頭部尖端處的熱應(yīng)力較大，應(yīng)力值約在10^8N／m^2數(shù)量級，晶體中部熱應(yīng)力分布較小且比較均勻，約為10^7N／m^2。為了防止晶體在生長過程中頭部尖端處以及變徑處的位錯延伸至晶體內(nèi)部，提出了在不同生長階段采用不同下降速度，并且在晶體下降至變徑處采用“回熔”操作的新工藝。實(shí)驗(yàn)結(jié)果表明：利用新工藝生長的晶體位錯密度明顯降低，約為2×10^2cm^-2，同時顯著地提高了晶體的利用率。
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Feng Keqin , Bai Chenguang , Yang Yi
2007, 36(6):1020-1023.
Abstract:采用Gleeble-1500D熱模擬機(jī)，通過對質(zhì)量分?jǐn)?shù)55％（Ti＋C）-45％Fe粉末壓坯分別升溫至250～800℃的解析實(shí)驗(yàn)，研究Fe-Ti-c體系在電場誘導(dǎo)下低溫燃燒合成的顯微組織演變。結(jié)果表明：在電場和大熱流密度的共同作用下，體系的點(diǎn)火溫度可大幅降低。當(dāng)加熱溫度在250～350℃之間，體系雖未發(fā)生化學(xué)反應(yīng)，但顯微結(jié)構(gòu)在一定程度隨溫度而發(fā)生變化；當(dāng)加熱溫度在350-470℃范圍內(nèi)，體系被點(diǎn)燃發(fā)生“熱爆”現(xiàn)象，而在燃燒合成反應(yīng)前期，合成TiC的反應(yīng)優(yōu)先發(fā)生；當(dāng)加熱溫度提高到470-670℃，合成TiC反應(yīng)發(fā)生的同時還伴隨有合成Fe2Ti的反應(yīng)；然而隨加熱溫度進(jìn)一步提高到670-800℃，F(xiàn)e2Ti會發(fā)生部分分解，進(jìn)而使得合成TiC的反應(yīng)繼續(xù)進(jìn)行。當(dāng)溫度達(dá)到800℃左右，該合成反應(yīng)全部完成，產(chǎn)物由Fe、TiC和少量Fe2Ti組成。此外，通過合成反應(yīng)所得呈圓球狀、細(xì)小的TiC顆粒均勻地分布在Fe基體中，且隨加熱溫度的提高而有所長大。
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Chen Xiaozhen , Zheng Ziqiao , Li Shichen , Wei Xiuyu , Chen Zhiguo
2007, 36(6):1024-1028.
Abstract:研究了微量Ce、Ag對一種Al-Cu-Li合金熱暴露后顯微組織和性能的影響。Ce的添加提高T1相的抗粗化能力,有利于穩(wěn)定合金熱暴露后的力學(xué)性能;Ag的缺少降低了T1相的穩(wěn)定性,使合金在150℃熱暴露后的強(qiáng)度損失較大,但卻使合金在200℃熱暴露后保持較高的強(qiáng)度,這與不含Ag的合金在200℃熱暴露時大量θ′相析出有關(guān)。
>材料科學(xué)
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Chen Xiaozhen , Zheng Ziqiao , Li Shichen , Wei Xiuyu , Chen Zhiguo
2007, 36(6):1024-1028.
Abstract:研究了微量Ce、Ag對一種Al-Cu-Li合金熱暴露后顯微組織和性能的影響。Ce的添加提高T1相的抗粗化能力，有利于穩(wěn)定合金熱暴露后的力學(xué)性能；Ag的缺少降低了乃相的穩(wěn)定性，使合金在150℃熱暴露后的強(qiáng)度損失較大，但卻使合金在200℃熱暴露后保持較高的強(qiáng)度，這與不含Ag的合金在200℃熱暴露時大量θ相析出有關(guān)。
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Yang Yingjun , Xing Dawei , Wang Gang , Sun Jianfei , Wei Sidong , Shen JunI
2007, 36(6):1029-1032.
Abstract:銅基大塊非晶合金Cu52.5Ti30Zr11.5Ni6與Cu53.1Ti31.4Zr9.5Ni6（at％）具有高的抗壓縮斷裂強(qiáng)度（σc,f），分別為2212MPa和2184MPa；斷裂伸長率（εc,f）分別為2．1％和2．2％。斷口微觀形貌分析表明，Cu基大塊非晶合金具有3種不同類型的微觀形貌，分別與斷口的3個斷裂擴(kuò)展區(qū)域相對應(yīng)。由于斷裂沿著2個不同方向進(jìn)行，條帶型脈狀網(wǎng)絡(luò)的產(chǎn)生，使得Cu基非晶具有高的抗壓縮斷裂強(qiáng)度。
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Huang Linjun , Liang Gongying , Sun Zhanbo
2007, 36(6):1033-1036.
Abstract:Amorphous and nanocrystalline Mg-based alloys (Mg65Cu25)100-xNdx (x=2,5,7,10) were prepared by melt-spinning. The microstructure of the as-quenched ribbons was characterized and the hydriding properties of these alloys were measured. The experiment results show that the as-quenched amorphous (Mg65Cu25)93Nd7 alloy display the best hydriding properties (hydriding kinetics and hydrogen absorption capacity),its maximum hydrogen capacity is 3.0 wt%H. The nanocrystalline (Mg65Cu25)98Nd2 alloy shows slower hydriding kinetics and lower hydrogen absorption capacity compared to the other Mg-Cu-Nd amorphous alloys. It is conformed that the glass-forming ability becomes strong with the increase of neodymium for the as-quenched (Mg65Cu25)100-xNdx alloys,which leads to the high H-capacity.
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Zhang Junying , Ge Qi , Yang Chun , Wang Tianmin
2007, 36(6):1037-1040.
Abstract:Light-storing photocatalyst was prepared by combining long afterglow phosphor with TiO2 photocatalyst film, and bactericidal effect of this material on E.coli was investigated. TiOz shows high bactericidal ability under irradiation of light source and can decompose bacterial cell completely, but can not function in the darkness. The long afterglow phosphor can supply light for TiOz film after irradiation source is cut off, and hence E.coli can be killed by the light-storing photocatalyst even in the dark. This light-storing photocatalyst can be irradiated intermittently while maintaining photocatalyst activity all the time.
>材料工藝
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Lu Shiqiang , Hu Chunwen , Li Xin , Wang Kelu , Dong Xianjuan , He Yuehui
2007, 36(6):1041-1045.
Abstract:CuCr50 powders were first activated by mechanical alloying (MA),then used to prepare the contact materials by vacuum hot pressing. The results indicate that the CuCr50 powder by MA is ametastabe and supersaturated solid solution,would dissolve during the followed hot pressing. The microstructures and properties of bulk CuCr50 materials vary with the dissolving amounts of supersaturated solid solution. A bulk CuCr50 material of high density with fine and homogeneous Cr particles distributed can be acquired at lower temperature for shorter holding time in hot pressing due to the mechanically activated effect of MA powders. As a result,the synthetical properties of bulk CuCr50 materials fabricated by this method are superior to those prepared by other methods.
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Li Wei , Ying Jierong , Wan Chunrong , Jiang Changyin , Tang Changping , Lei Min
2007, 36(6):1046-1050.
Abstract:用FeSO4、H3PO4、(NH4)2HPO4、NH3·H2O為原料合成NH4FePO4·H2O前驅(qū)體,再與LiCO3和蔗糖均勻混合,烘干后埋入活性炭粉中,在最大功率為800 W的家用微波爐中以320～640 W功率加熱一定時間,獲得LiFePO4.用掃描電鏡和X射線衍射分析對NH4FePO4.H2O和LiFePO4的形貌結(jié)構(gòu)進(jìn)行了表征.研究了微波輸入功率、加熱時間對LiFePO4結(jié)構(gòu)和電化學(xué)性能的影響.研究表明,在320 W下微波加熱15 min得到的LiFePO4材料,具有良好的電化學(xué)性能.在0.05 C放電倍率下可達(dá)到156 mAh/g的放電比容量,在0.5 C放電倍率下仍可達(dá)到115 mAh/g的放電比容量.
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Li Lingxia , Wang Dapeng , Guo Rui , Wang Hongru , Meng Xudong , Li Huiling
2007, 36(6):1051-1054.
Abstract:研究了鎂離子在金屬-電介質(zhì)復(fù)合材料中的改性作用。通過SEM、EDS、XRD等分析手段綜合得出Mg^2＋取代了BaTiO3晶格中B位的Ti^4＋，并使置換出來的Ti^4＋在樣品表面形成富集。介電性能分析證明Mg^2＋可以明顯降低系統(tǒng)介電損耗，展寬并壓低居里峰。當(dāng)Mg^2＋添加量為0．9％（摩爾分?jǐn)?shù)），系統(tǒng)介電常數(shù)高達(dá)11395，介電損耗為0．006，并在-55～150℃范圍內(nèi)容量變化率〈±10％。
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2007, 36(6):1055-1057.
Abstract:Gold nanoparticles are prepared in O/W microemulsion of SDS/Vc/H2O (0.001 mol?L-1 HAuCl4) system by using Vc as the reducing agent. The size of obtained polygonal gold nanoparticles is from 5 nm to 20 nm,and increases with the content increase of HAuCl4 in O/W microemulsion in the condition of SDS/Vc weight ratio of 50/50. The formation mechanism of gold nanoparticles is discussed in the present paper.
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Zhou Zenglin , Song Yueqing , Cui Shun , Huang Zhuo , Guo Zhimeng , Qu Xuanhui
2007, 36(6):1058-1062.
Abstract:The La0.7Mg0.3(Ni0.85-xCo0.15Alx)3.4 hydrogen storage electrode alloys were prepared by cold crucible melting under argon gas atmosphere. The phase structure of these alloys and the electrochemical properties and surface of corresponding electrodes were investigated by means of XRD and tri-electrode test system and SEM. Rietveld analyses show that all these alloys consist of hexagonal Ce2Ni7-type main-phase,hexagonal CaCu5-type phase,rhombohedral PuNi3-type phase,cubic MgCu2-type Laves-phase and orthorhombic BCr-type phase. The Ce2Ni7-type main-phase content and the cell volume of all these phases increase with increasing of x. P-C isotherms show that hydrogen-desorption plateau region narrows,and the plateau pressure decreases and the plateau becomes steeper with increasing of x. The electrochemical results show that maximum discharge capacity and high-rate dischargeability decrease,cyclic stability is improved markedly with increasing of x.
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Xu Sankui , Wang Xiangyu , Liang Lizhen
2007, 36(6):1063-1065.
Abstract:用正交實(shí)驗(yàn)考察了溶液溫度、pH值、攪拌速度等因素對催化劑吸附量的影響規(guī)律，并據(jù)此用浸漬及甲醛還原法制備了系列Ru／C催化劑，在0．5MPa、120℃下測得葡萄糖加氫生成山梨醇的催化活性、山梨醇選擇性和催化劑的穩(wěn)定性。并運(yùn)用程序升溫還原TPR（temperatureprogrammedreduction）技術(shù)研究了催化劑的表面還原性質(zhì)。結(jié)果表明：釕的負(fù)載量對Ru／C催化劑的性能影響較大，釕負(fù)載量為5％時，制得的催化劑具有較佳的各項(xiàng)性能。釕的負(fù)載量越少時，負(fù)載釕的分散度越高，釕與載體間作用力越強(qiáng)，催化劑的還原溫度越高。同時，隨著含釕量的增加，催化劑的還原峰發(fā)生明顯的變化，負(fù)載量為5％時出現(xiàn)了明顯的肩峰，化學(xué)吸附是催化活性的主要來源。
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Liu Weiqiang , Yue Ming , Zhang Jiuxing , Wang Gongping , Li Tao
2007, 36(6):1066-1069.
Abstract:The electrochemical properties of Nd2Fe14B single crystal grain,conventional sintered NdFeB and SPS NdFeB in electrolyte were studied. The microstructures and compositions of the magnets were investigated with scanning electron microscope (SEM) and energy dispersive X-ray detector (EDX). Polarization curves in 3.5% NaCl solution show that Nd2Fe14B single crystal grain has displayed most positive corrosion potential and the SPS NdFeB magnet has more noble potentials compared with the conventional sintered one. Compared with conventional sintered NdFeB magnet,SPS processed magnet has original microstructure i.e. the grain size of the Nd2Fe14B main phase is fine and uniform,and the fine Nd-rich phase does not form along the grain boundaries of main phase,but agglomerates into the triple junctions. The pathways for corrosion propagation are restricted and the inter-granular corrosion process though Nd-rich phase in the magnet is suppressed effectively. Therefore,the SPS NdFeB magnet possesses excellent corrosion resistance. Autoclaves test indicates that a strong correlation has been established between an increase in the total rare earth level,which corresponds to the amount of Nd-rich phase,and an increase in the corrosion rate. The results show that chemical character; microstructure and the amount of Nd-rich phase determine the corrosion resistance of magnets and indicate an intergranular corrosion leads to poor corrosion resistance.
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2007, 36(6):1070-1073.
Abstract:研究了一種新型的制備金屬藕狀多孔結(jié)構(gòu)技術(shù)——選區(qū)激光燒結(jié)，著重說明該技術(shù)的基本原理和工藝過程，并利用此制備技術(shù)成功獲得了藕狀多孔試樣。利用SEM分析了316不銹鋼藕狀多孔試樣的微觀孔隙特征，并測定其孔隙率，結(jié)果表明其孔徑大小分布均勻（2-4μm），平均孔隙率約為60％，孔隙貫通性良好；初步探討了選區(qū)激光燒結(jié)制備316不銹鋼藕狀多孔結(jié)構(gòu)的成形機(jī)制。
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Hu Tao , Chu Chenglin , Sun Weibin , Wang Juan , Zhou Jingyan , Dong Yinsheng , Pu Yaopu , Lin Pinghua , Paul K Chu
2007, 36(6):1074-1077.
Abstract:通過高級氧化法對NiTi形狀記憶合金進(jìn)行表面改性，SEM和TF—XRD分析證實(shí)，羥自由基（·OH）氧化后的NiTi形狀記憶合金表面生成了金紅石和銳鈦礦結(jié)構(gòu)的二氧化鈦薄膜。通過測定動態(tài)凝血時間、溶血率和研究血小板黏附行為等方法進(jìn)行了血液相容性評估。結(jié)果表明，經(jīng)高級氧化法表面改性后的NiTi形狀記憶合金血液相容性獲得了明顯的改善。
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Sheng Jianfeng , Feng Haibo , Yu Ronghai
2007, 36(6):1078-1081.
Abstract:A new Y6Fe60.5Co11.5B22 Fe-based bulk metallic glass with a maximum diameter of 2 mm has been fabricated by suction casting method in a water-cooled copper mould. The interrelationship between cooling rates and magnetic properties were investigated and the critical cooling rate of the amorphous alloy was calculated. The bulk amorphous alloy has a coercivity of 2.53 A/m,a saturated magnetization of 1.24 T,and a high initial susceptibility. The critical cooling rate (Rc) of the Y6Fe60.5Co11.5B22 amorphous alloy was determined to be about 119 K/s.
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Zhu Guoli , Ye Jinwen , Liu Ying , Wang Xiaohong , Zhang Zhongyu , Gao Shengji , Tu Mingjing
2007, 36(6):1082-1084.
Abstract:The microstructure and phase composition of Sm-Fe alloy during quenching process were investigated by means of SEM, XRD, EDX, and AFM, etc. It is indicated that the Sm-Fe alloy cast consists of Sm2Fe17 phase, Sm-rich phase and a mount of a-Fe phase, and the alloy of single Sm2Fel7-phase was obtained after homogenization annealing. The alloy is composed of the Sm2Fe17 phase with Th2Zn17-type structure and a few a-Fe phase, with unhomogeneous grain sizes of about 100 nm when the quenching velocity is 10 m/s. But at 20 m/s, the alloy still contains Sm2Fe17 and a-Fe phases, but the content of a-Fe is increased when compared with at 10 m/s. At the same time, the stable Sm2Fe17 phase starts to convert into sub-stable SmloFe90 phase. At 30 m/s, the alloy is completely composed of SmloFe90 phase with the ThCuT-type structure and homogeneous grain size of40-50 nm.
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Zhang Dailan , Bai Xinde , Li Juan , Chen Jianxin , Wu Zhiming , Zhu Guosheng
2007, 36(6):1085-1087.
Abstract:利用微弧氧化技術(shù)，以NaOH為電解液，對Zr-Nb合金進(jìn)行表面處理，以改善其抗溶液腐蝕性能。利用SEM觀察到Zr-Nb合金微弧氧化膜厚約8μm，膜層為一連續(xù)整體，厚度均勻，與基體結(jié)合牢固。X射線衍射分析表明，微弧氧化膜主要由四方和單斜相的二氧化鋯組成。通過電化學(xué)極化曲線測量，對Zr-Nb合金微弧氧化膜的抗腐蝕性能進(jìn)行了評價，結(jié)果表明，氧化膜抗腐蝕性能比基體提高顯著。
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Wang Huijie , Li Anhua , Li Wei
2007, 36(6):1088-1090.
Abstract:The effects of PrHx addition on the magnetic properties, microstructure and bending strength have been studied for the sintered Nd-Fe-B magnets. It shows that the bending strength and coercivity can be effectively improved and enhanced by the addition of PrHx for the experimental magnets. The magnets have the optimal microstructure according to SEM images, and the atoms diffusion can be potentially improved among the magnetic main phase Nd2Fel4B after the PrHx addition.
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2007, 36(6):1091-1094.
Abstract:采用機(jī)械合金化（MA）工藝，以W-25％CuO為原料，球磨參數(shù)設(shè)置為：球料比20：1、球磨轉(zhuǎn)速500r／min，球磨時間范圍1-40h，采用球磨20min、空氣冷卻30min的循環(huán)球磨方式。對不同球磨時間條件下制備的粉末進(jìn)行了x射線衍射和透射電鏡分析。結(jié)果表明，通過MA工藝可在較短時間內(nèi)（lh）獲得W-Cu納米晶粉末，球磨時粉體中的CuO發(fā)生了還原，部分W被氧化成WOx（x=2～3），球磨后w粉的平均晶粒尺寸為12．5nm左右，最小晶粒5～6nm；W粉顆粒的最終形態(tài)為球形，并被Cu所包覆。
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Huang Yunxia , Cao Quanxi , Li Zhimin , Wang Yupeng , Li Guifang , Wei Yunge
2007, 36(6):1095-1098.
Abstract:以sn-Pd膠體溶液為活化劑，對空心微球的表面進(jìn)行活化，并采用化學(xué)鍍工藝，在其表面分別鍍Co和Co-Fe薄膜。利用掃描電子顯微鏡（SEM）、能量散射譜（EDS）和x-射線衍射儀（XRD）分別對鍍膜前后的空心微球進(jìn)行表征，用網(wǎng)絡(luò)矢量分析儀測試鍍膜后空心微球的電磁損耗和微波吸收性能。結(jié)果表明：經(jīng)過活化后的空心微球表面分別淀積了均勻、致密的Co和Co-Fe薄膜。改性后的空心微球在2-18GHz的頻率范圍內(nèi)對電磁波有不同程度的吸收，具有寬頻的吸收特性。
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Yu Xiaojiao , Yao Binghua , Nagaosa Yukio
2007, 36(6):1099-1101.
Abstract:The extraction of Pr3+was studied by using heptane containing bis(2-ethylhexyl)phosphinic acid in sodium perchlorate,chloroacetic acid and citric acid medium,respectively. The effects of extraction equilibrium time,different mediums,PIA-8 concentrations upon extraction Pr3+ and that of concentration of back extraction agent on back extraction rate of Pr3+ were discussed. The composition of the extracted compound was shown to be La(HA2)3.The pH1/2 values of La3+,Ce3+,Pr3+,Nd3+,Sm3+ and Eu3+ in different mediums were determined,it is 3.69,3.30,3.16,3.10,2.68 and 2.54 in sodium perchlorate medium respectively,3.65,3.27,3.12,3.08,2.66 and 2.50 in chloroacetic acid mediums,respectively,4.34,4.26,4.11,3.91,3.57 and 3.38 in citric acid mediums,respectively.
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Huang Jingjing , Ren Yibin , Zhang Bingchun , Yang Ke
2007, 36(6):1102-1105.
Abstract:The vitro blood anticoagulant activities,including rothrombin time (PT),plasma recalcification time (RT) and kinetic cloting time,were measured and compared for pure magnesium,magnesium alloys and a comparison material (316L stainless steel). The pure magnesium rods were implanted into the back muscle of rats to evaluate the osteo-induction.The results showed that the blood anticoagulant activities were in the order of Mg
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Zhang Guikai , Lu Guangda , Chen Huchi , Yin Chen
2007, 36(6):1106-1109.
Abstract:為了解雜質(zhì)氣體對鈀柱氫氘排代性能的影響程度，利用快排代法考察了排代氫中添加CO，O2，CH4，CO2等氣體后室溫下鈀柱氫氘排代效率的變化情況，并測量了鈀表面O2，CO，CH4的等溫吸附曲線。結(jié)果表明：H2中僅加入10μL／L的CO，排代性能已顯著下降，隨CO含量的增加，排代性能隨之顯著降低，當(dāng)CO含量增至3000μL／L時將幾乎沒有排代效果；O2的影響比CO弱，H2中含3000μL/L的O2時排代性能約下降20％；然而當(dāng)H2中含3000μL／L的CO2時排代性能約下降3．2％；CH4的影響則相對可忽略。
>綜合評述
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Chao Yajun , Yuan Xianxia , Ma Zifeng
2007, 36(6):1110-1114.
Abstract:Electrochemical capacitor (ECs) is one of the novel energy-storage and conversion devices,by which the electric energy can be obtained from the electrochemical double-layer or the redox reaction occurring on the interface between electrode and electrolyte with the advantages of large power density,large energy density,excellent reversibility and long cycle life. In the present paper,the recent application progresses and developments of the composite electrode materials for ECs have been reviewed and introduced in detail.
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iZuan Meini , Yang Yanqing , Ma Zhijun , Ltl Xianghong , Li Jiankang , Chen Yan
2007, 36(6):1115-1118.
Abstract:The effect factors, micro measurements and numerical simulation were reviewed and discussed for the interracial strength of SiC fiber reinforced titanium composites. Special attentions were paid to the limitation of the experimental measuring numerical modeling. The way of quantitative study on the interracial bonding strength was pointed out for the composites
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Chen Junliang , Fang Fang , Zhang Jing , Zhu Jian , Chen Guorong , Sun Dalin
2007, 36(6):1119-1123.
Abstract:Nanotechnology can remarkably modify the hydrogen storage properties of hydrogen storage materials. The latest progresses on the nanotechnological aspects of hydrogen storage materials are described and discussed in this paper. Some problems to be overcome are pointed out, and some suggestions for future work are given.
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2007, 36(6):1124-1128.
Abstract:The changes of A and B elements have great effects on the electrochemical properties and microstructure for the rare-earth based ABs-type hydrogen storage alloy as the cathode material of Ni-MH batteries. The electrochemical properties of rare earth-based hydrogen storage alloy, and the substitution of A and B in the ABs-type hydrogen storage alloy are reviewed and the relationship of substituted elements and electrochemical properties are summarized in order to provide some ideas for researchers.
