- Volume 36,Issue 10,2007 Table of Contents
>綜合評述
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Feng Bo , Weng Jie , Qu Shuxin , Lu Xiong , Wang Jianxin
2007, 36(10):1693-1697.
Abstract:The surface modification of the material prepared by nano-technology becomes one of the recent trends in development of biomaterials. This paper reviews the progress on nano-apatite coatings and self-assembled monolayers on biomedical titanium surfaces so as to provide material engineers and scientists as well as concerned readers with information.
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2007, 36(10):1698-1701.
Abstract:Boron is a promising element for hydrogen storage alloys. Boron and its compounds used as an additive in negative electrode materials in metal hydridenickel battery will dramatically improve the performances of hydrogen storage alloys electrode. The influence of boron addition on the mechanical properties, dynamic properties and thermodynamic properties of hydrogen storage alloys is reviewed. The control of boron content in the alloys is of great importance for improving the performances MH-Ni batteries
>材料科學
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Li Kezhi , Wang Chuang , Li Hejun , Luo Fa , Hou Dangshe
2007, 36(10):1702-1708.
Abstract:Carbon-fiber-reinforced cement-based composites were prepared and their fracture surfaces were observed by scanning electron microscopy. The reflectivities of the composites in the frequency ranges of 4-8 GHz and 8-18 GHz were measured by using the Naval Research Laboratory testing system to assess the electromagnetic interference through investigating the influence of carbon fiber contents of 0.2, 0.4, 0.6, 0.8, 1.0 wt% on their reflectivities. Results showed that all of the measured reflectivities data were less than -10 dB in the lower frequency range and there was mainly absorption of electromagnetic waves. However, the reflectivity was more than -10 dB when the fiber mass fraction was over 0.6% in the higher frequency range, and the electromagnetic waves were mainly reflected. As the mass fraction increased, the reflectivity changed. The minimum reflectivity in the lower frequency range was -15.1 dB when the mass fraction was 0.6%, whereas that in the higher frequency range was -19.3 dB when the mass fraction was 0.4%.
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Lu Xianghong , Yang Yanqin , Luo Xian , Liu Yucheng , Huang Bin , Chen Yan
2007, 36(10):1709-1716.
Abstract:通過Ti6A14V／TA1擴散偶的制備及其熱處理試驗，運用OPM，SEM以及EDS技術(shù)對擴散連接區(qū)域的組織、形貌、成分進行分析。結(jié)果表明：擴散連接界面充分結(jié)合，合金元素A1和V從Ti6A14V側(cè)向TA1側(cè)擴散，而Ti原子向Ti6A14V側(cè)擴散，其成分過渡區(qū)滿足拋物線規(guī)律；同時，根據(jù)柯勒方程，借助米德瑪生成熱模型，從熱力學上推導三元體系的計算公式，得出熱力學相互作用因子，并根據(jù)求得溶質(zhì)元素的互擴散系數(shù)，通過唯象公式的數(shù)值解法，得出擴散元素在連接界面處的理論濃度分布圖：實驗值與理論模擬結(jié)果吻合得很好，因此，能夠很好的預測擴散連接界面相關(guān)元素的濃度分布。
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Yang Guangyu , Jie Wanqi , Zhang Runqiang , Hao Qitang , Li Jiehua
2007, 36(10):1717-1721.
Abstract:研究了ZL205A鋁合金在近液相線不同等溫溫度和等溫時間條件下的微觀組織轉(zhuǎn)變規(guī)律。結(jié)果表明，a（A1）晶粒直徑與等溫時間滿足關(guān)系式r^-3-r0^3=k^1-t。系數(shù)k＇值隨等溫溫度變化，在622℃和631℃條件下對應的k＇值分別為4．288×10^10m^3／s和5．962×10^-10m^3／s。實驗合金的等溫過程基本上分為球化預備階段、球化階段和長大粗化階段。等溫溫度提高，固相體積分數(shù)也隨之降低，有利于加速。α（Al）晶粒球化和獲得均勻的球狀等軸固相顆粒。實驗合金等溫組織演變過程是溶質(zhì)傳輸和空位擴散、以及液固界面張力共同作用的結(jié)果。溶質(zhì)擴散作用在開始階段起主導作用，而界面張力在中后期占主要作用。
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Chen Ruirun , Ding Hongsheng , Guo Jingjie , Liang Fuzhen , Zhang Ziqin , Bi Weisheng , Liu Lin , Fu Hengzhi
2007, 36(10):1722-1727.
Abstract:In order for making efficient use of the cold crucible, optimizing technological parameters and obtaining perfect metallurgy quality billets, the temperature fields of the cold crucible continuous melting and directional solidification of Ti6Al4V have been calculated. Boundary conditions were determined according to the feeding billet and fresh billet formed by induction heating, the meniscus formed by electromagnetic force. The meniscus shape was obtained from the parabola approaching the experimental one. Continuous casting was achieved by distinguishing from the moving unit at different positions. The calculation results under the conditions of 52 kW and 3 mm/min velocity show that the feeding billet begin to melt at 45 s and the meniscus was formed at 70s, then the melt had superheat degree and the skull was formed, the melt reached the highest temperature at 115 s. The feeding billet was melted completely and the temperature field was steady, the shape and the position of solidification front were invariable in the process of continuous melting and directional solidification. The solidification front was planar in the middle but upwarp on both sides, most of heat was transferred in axial direction. Experimental results are agreement with the calculation results, which proves that the procedure is accurate for calculating the temperature field of cold crucible continuous melting and directional solidification.
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Jiang Bin , Xu Binshi , Dong Shiyun , Ding Peidao
2007, 36(10):1728-1731.
Abstract:The comparative study of contact fatigue properties between the n-SiO2/Ni coating and the nickel coating prepared by electro-brush plating was carried out by means of microstructure characterization and taking account of effect of heat treatment on it. Results showed that the microstructure of n-SiO2/Ni composite coating was finer and the distribution of nano-particles incorporated in the nickel matrix was uniformly dispersive. The contact fatigue life of the heat-treated n-SiO2/Ni coating was over 1.3 million cycles, and 4.67 times that of the nickel coating, and almost equivalent to that of the as-deposited n-SiO2/Ni coating. The fracture zones of the heat-treated n-SiO2/Ni coating exhibited the feature of plastic deformation. The heat treatment can improve the ability of plastic deformation during the contact fatigue processes.
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Wan Diqing , Yang Gencang , Zhu Man , Cheng Suling , Zhou Yaohe
2007, 36(10):1732-1735.
Abstract:采用XRD，SEM，EDX，TEM，DTA等試驗分析手段及快淬方法對MgToZn28Y2準晶合金凝固過程、凝固組織以及對和準晶形成相關(guān)的包晶反應初生相進行了研究。Mg70Zn28Y2合金鑄態(tài)組織由α-Mg枝晶，Mg7Zn3基體相和二十面體準晶相組成。在鑄態(tài)Mg-Zn-Y合金中觀察到了完美的呈5次旋轉(zhuǎn)對稱性的平衡態(tài)準晶晶體外形。Mg70Zn28Y2合金凝固過程中準晶由包晶反應生成。差熱分析顯示包晶反應初生相在563℃形成，準晶形成的溫度為416℃。能譜分析結(jié)果顯示包晶反應初生相的成分為Mg22.94Zn55.73Y21.33。通過快淬方法保留的包晶反應初生相呈現(xiàn)粗大枝晶狀。然而，通過背散射圖片中所觀察到準晶中的殘留包晶初生相尺寸較小。
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Zhou Xiangyang , Jiang Zhuangde , Wang Hairong
2007, 36(10):1736-1740.
Abstract:對等離子法制備的400nm厚Cu膜-Si（100）基底系統(tǒng)（退火溫度為300℃）進行了納米壓入實驗，目的是尋找一種可靠的軟金屬薄膜本征模量的評定方法。研究結(jié)果表明：基于等模量假設的計算方法可以有效避免材料堆積行為和最小化基底效應對薄膜彈性模量評定的顯著影響。結(jié)合使用連續(xù)剛度測試（CSM）技術(shù)，Oliver—Pharr分析法中材料蠕變及熱漂移行為的誤差影響因素也被消除。利用這種方法得到的Cu膜彈性模量為（92．2±1．8）GPa，和文獻值符合較好。與通用的利用數(shù)學模型從復合模量中分離出薄膜模量的方法相比，這種方法更為準確和簡便。
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Yang Wen , Liu Jiabin , Meng Liang
2007, 36(10):1741-1744.
Abstract:采用冷拉拔制備了Cu-6％Ag及Cu-12％Ag纖維相復合強化合金線材，研究了組織纖維化對Cu—Ag合金強度與彈性模量的影響。隨變形程度的增加，合金抗拉強度和彈性模量在明顯升高后趨于飽和。Cu-12％Ag合金比Cu-6％Ag合金有更高的應變硬化速率和抗拉強度。在較低變形程度范圍內(nèi)，Cu-6％Ag合金的彈性模量高于Cu-12％Ag合金。在較高變形程度范圍內(nèi)，Cu-6％Ag合金的彈性模量低于Cu-12％Ag合金。纖維化組織中的高密度晶體缺陷使得兩種Ag含量的合金彈性模量均低于理論預測值。合金的強度和彈性模量主要取決于共晶體數(shù)量、相界面密度、變形抗力及兩相之間的變形協(xié)調(diào)行為。
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Ma Quan , Liu Xianghong , Chen Zili , Zhou Lian , Zhang Pingxiang , Du Shejun , Wu Xiaozu , Lu Yafeng
2007, 36(10):1745-1748.
Abstract:研究了Nb／Ti擴散的特性和機理以及經(jīng)過相同時間、不同溫度時效熱處理的Nb／Ti擴散偶樣品中NbTi合金層的厚度、保溫結(jié)束后淬火與爐冷的擴散偶樣品中NbTi合金層微觀結(jié)構(gòu)的區(qū)別，討論了它們對NbTi超導體微觀結(jié)構(gòu)和性能的影響。研究表明通過選擇合適的擴散制度能獲得理想的微觀結(jié)構(gòu)和制備出高性能的NbTi超導線材。
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Li He , Yao Suwei , Zhang Weiguo , Wang Hongzhi , Ben Yuheng
2007, 36(10):1749-1753.
Abstract:采用陽極氧化法在鈦片上制備了垂直排列的TiO2納米管陣列，利用SEMXRD對納米管陣列的形貌和結(jié)構(gòu)進行了表征，并通過電化學交流阻抗譜、光照開路電位譜和瞬態(tài)光電流譜技術(shù)對納米管陣列電極的光電化學特性進行了研究。實驗結(jié)果表明，TiO2納米管的內(nèi)徑約為90nm，管壁約為10nm，納米管陣列厚度約為500nm，經(jīng)600℃退火處理后，轉(zhuǎn)變?yōu)殇J鈦礦型與金紅石型的混晶結(jié)構(gòu)。光電測試結(jié)果表明，隨著退火溫度升高，TiO2納米管陣列電極的界面電荷轉(zhuǎn)移電阻減小，光電流逐漸增大，光照開路電壓增大，至600℃達到最大，當退火溫度繼續(xù)升高，電極的光電性能急劇下降。與TiO2納米多孔膜電極相比，光電性能顯著提高，這主要歸因于TiO2納米管陣列更大的孔隙率和比表面積。
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Peng Ke , Yi Maozhong , Ran Liping
2007, 36(10):1754-1758.
Abstract:根據(jù)固體與分子經(jīng)驗電子理論，通過鍵距差（BLD）方法，計算了金屬間化合物WSi2的價電子結(jié)構(gòu)和理論結(jié)合能。結(jié)果表明，WSi2理論結(jié)合能為1859．5kJ／mol，與實驗值吻合。WSi2晶體中，沿〈331〉位向分布的W—Si鍵的鍵能最大，EA=33．397kJ／mol，且有32個等同鍵數(shù)，是晶體熔化時必須破壞的主干鍵絡，因而WSi2具有高熔點。WSi2晶體中含有較高密度的晶格電子，使WSi2具有良好的導電性。WSi2晶體中鍵絡分布不均勻性是導致晶體脆性的主要原因。
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Zeng Gang , Li Mingwei , Zhang Qingmao , Han Jiecai , He Xiaodong
2007, 36(10):1759-1762.
Abstract:A mathematical model for the calculation of TiAl alloy evaporation and deposition was developed. The activity coefficients of the elements represent the interaction between the components in the liquid pool. It is found that the main parameters affecting the evaporation rate include the activity coefficients and saturation vapor pressures of the elements. Experimental data are coincided with calculated data well. The results show that TiAl alloy can be deposited using the so-called single-crucible consisting of a water-cooled copper crucible with the base material being fed continuously through the bottom of the crucible.
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Li Ning , Qiu Youxu Zhang Wei , Wen Yunhua Zhang Yong , Zhou Yonggui
2007, 36(10):1763-1766.
Abstract:研究了超細晶硬質(zhì)合金VC／Cr3C2抑制劑作用及抑制機理。研究發(fā)現(xiàn)復合添加VC／Cr3C2可以有效抑制WC—10Co合金燒結(jié)過程中晶粒的連續(xù)長大，合金平均晶粒尺寸為0．5μm，具有較高TRS（橫向斷裂強度TransverseRuptureStrength）和硬度。TEM和EDS分析發(fā)現(xiàn)抑制劑元素的主要存在方式是溶解在粘結(jié)相中且分布均勻，未發(fā)現(xiàn)抑制劑元素偏聚和第二相析出，說明抑制機理在于抑制劑元素溶入粘結(jié)相Co后，顯著降低W，C在Co中的溶解度，使液相燒結(jié)階段WC晶粒的溶解一析出過程受到阻礙，從而抑制液相燒結(jié)階段的晶粒連續(xù)長大。
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Lu Baiping , Shen Jun , Liu Lin , Fu Hengzhi
2007, 36(10):1767-1771.
Abstract:研究了電磁成形大寬厚比板狀件的感應加熱特性，推導了電磁成形大寬厚比板狀件單位體積感應加熱功率公式。結(jié)果表明：中小尺寸的大寬厚比板狀件角部感應加熱功率與角部半徑的平方成正比，角部半徑越小，感應加熱功率越小，板狀件角部越難以熔化。單頻磁場條件下，板狀件角部和寬面部分均勻熔化的條件是板狀件角部半徑大于等于板狀件寬面處電流透入深度。角部半徑小于板狀件寬面處電流透入深度時，電磁場難以使板狀件角部和寬面部分均勻熔化。針對角部半徑小于寬面處電流透入深度的板狀件，提出雙頻電磁成形的方法，并成功制備出具有預設橫截面形狀的大寬厚比耐熱不銹鋼板狀件。
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Wang Mingwei , Zhang Liwen , Zhang Fanyun , Li Chenhui
2007, 36(10):1772-1775.
Abstract:A 2-D nonlinear thermo-mechanical coupled finite element model was developed. Numerical simulation of vacuum hot bulge forming process of titanium alloy cylindrical workpiece was carried out using the FE software MSC.Mrac. The temperature field and displacement field of vacuum hot bulge forming process of titanium alloy cylindrical workpiece were calculated using the model. The corresponding experiments were carried out. The simulated results are in good agreement with the experimental results, The wall thickness effects of the cylindrical workpiece were simulated numerically using the developed model. The relationships between bending angle of cylindrical workpiece and wall thickness, between maximum bulge height and wall thickness and between residual stress and wall thickness were discussed under certain technical conditions during the vacuum hot bulge forming process. The results will lay a theoretic foundation for optimizing technical parameters of vacuum hot bulge forming of titanium alloy in future manufacturing process.
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You Li , Song Xiping , Lin Zhi , Zhang Bei
2007, 36(10):1776-1779.
Abstract:通過用納米壓入法和靜態(tài)拉伸法對β-Ti絲、不銹鋼絲以及3種NiTi絲進行彈性模量的測量。實驗表明，納米壓入法彈性模量比靜態(tài)拉伸法彈性模量大，并且材料的彈性模量越低，二者相差越大，其原因同試樣的表面硬化層和尺寸效應有關(guān)。通過分析比較，建立了金屬絲彈性模量的納米壓入法和靜態(tài)拉伸法所得值之間的相關(guān)關(guān)系。
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Peng Delin , Shen Jun , Sun Jianfei
2007, 36(10):1780-1783.
Abstract:利用電弧熔煉及銅模快速鑄造的方法，制備Zr412Ti13.8Cu125Ni10Be225塊體非晶合金，通過電化學方法向塊體非晶中充入氫。研究了氫對塊體非晶合金電子結(jié)合能和電阻率的影響。結(jié)果表明：氫能夠提高非晶合金原子的電子結(jié)合能；當氫容量等于29％（摩爾分數(shù)，下同）時，電阻率無明顯的變化；氫容量等于62％和92％時，電阻率隨著氫容量的增加顯著降低；并且，充氫使電阻率突變溫度降低。
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Sun Yaru , Sun Wenru , Sun Xiaofeng , Guo Shouren , Liu Zheng , Hu Zhuangqi
2007, 36(10):1788-1792.
Abstract:研究了改變Thermo—Span合金的Al，Cr含量對合金熱膨脹系數(shù)、力學性能和650℃氧化性能的影響。當合金中Al含量由0．45％提高到1．5％，Cr含量由5．5％降低到3．0％，合金20～800℃的膨脹系數(shù)顯著降低，650℃，600MPa的光滑持久性能由354h提高到597h，室溫拉伸強度明顯增大，650℃，100h氧化速率稍有提高。Al含量增加，γ‘相析出增多。Cr含量較高時，氧化層和基體界面處的Cr濃度較高，提高了抗氧化性。降低Cr含量，提高Al含量，氧化層與基體界面處的Cr富集程度降低，Al的富集程度提高，合金的抗氧化性雖然有所降低，但幅度不大，仍保持為完全抗氧化級別。
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Chen Jiangli , Xu Zhuo , Qu Shaobo , Liu Xiaohui , Wei Xiaoyong
2007, 36(10):1793-1796.
Abstract:以PZT5和（Mg0.5Zn0．5）Fe2O4為原料，合成了不同配比的鐵電／鐵磁復相材料。XRD和SEM研究結(jié)果表明復相材料中只含有鈣鈦礦結(jié)構(gòu)的PZT5和尖晶石結(jié)構(gòu)的（Mg0.5Zn0.5）Fe2O4，無雜相生成，這說明共燒過程中兩者沒有發(fā)生明顯的化學反應。介電頻譜表明，相對介電常數(shù)隨PZT5含量的增加而增加（測試頻率在30MHz以下），介電溫譜表明，居里溫度隨頻率升高而向高溫移動（其值分別為250，300，326，372℃）。電滯回線呈現(xiàn)了材料的漏電流較大的特點。磁滯回線表明，這種復相材料具有亞鐵磁性，飽和磁化強度隨鐵氧體含量的增加而增加。性能測試表明，這種由PZT5和（Mg0.5Zn0.5）Fe2O4共同組成的復相材料對外同時表現(xiàn)出鐵電性和鐵磁性。
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Liang Minjie , Chen Zheng , Wang Yongxin , Chu Zhong
2007, 36(10):1797-1801.
Abstract:采用三元微觀相場動力學模型，模擬研究了973，1173，1253K時效溫度下，Ni75Al15Fe10合金中γ’相的早期沉淀過程。通過對該合金原子顯微形貌，長程序參數(shù)和濃度及Fe原子在不同格點占位分數(shù)隨時間演化的模擬計算分析得出：隨著溫度的升高，Ni75Al15Fe10合金的沉淀機制由等成分有序化兼失穩(wěn)分解機制向非經(jīng)典形核長大機制過渡；γ’相沉淀析出的孕育期變長；Fe原子在B格點的占位越來越困難，占位幾率降低；合金沉淀析出的γ’相為單一Ll2結(jié)構(gòu)的Ni3（AlFe）復合相。
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Liu Jing , Li Qian , Chou Kuochih , Lin Genwen
2007, 36(10):1802-1806.
Abstract:利用一種新模型分析了納米晶鎂粉的吸放氫動力學，量化了球磨和添加劑Pd對鎂粉吸放氫動力學性能的改善效果。結(jié)果表明，球磨能大幅度降低氫化反應活化能，提高鎂粉的氫化速率30倍。添加1％（質(zhì)量分數(shù)）Pd的納米鎂粉（30nm）的吸放氫速率比未添加Pd的納米鎂粉（30nm）的吸氫速率提高6．6倍。模型計算出30nmMg-1％Pd（質(zhì)量分數(shù)）合金的吸氫活化能為38．74kJ／molH2。
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Ning Yuantao , Zhang Xiaohui , Wu Yuejun
2007, 36(10):1807-1810.
Abstract:研究了形變態(tài)Cu-10Ag和Cu-10Ag-RE合金原位纖維復合材料時效強化效應。在300℃以下溫度時效顯示連續(xù)沉淀并導致合金強化，在300℃以上溫度時效顯示不連續(xù)沉淀，析出片層狀Ag沉淀并與Cu基體保持共格位向關(guān)系。在真應變η=6時效，合金具有高的時效強化效應，其極限拉伸強度增幅可達約12％；而在真應變η=9．8時效，時效強化效應減弱，極限拉伸強度增幅約4％-5％。微量Ce或Y添加劑提高Cu-10Ag合金的時效強化效應及不連續(xù)沉淀溫度。
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Song Shuxiang , Zhou Zhangjian , Du Juan , Yao Weizhi , Ge Changchun
2007, 36(10):1811-1814.
Abstract:The plasma sprayed tungsten coatings were prepared on oxygen free copper substrates, which are to be used as the plasma-facing materials of the divergent components in fusion reactors. The influences of different interlayers on bonding strengths of the plasma-sprayed tungsten coatings were compared. The morphologies and compositions of the coatings were observed and analysed by SEM, EDS. It was found that the bond between copper and the coating was relatively loose, and the bond between tungsten and the coating was relatively dense. Tensile tests indicated that the tungsten coating without any interlayer showed higher bonding strength than that of the other specimens.
>材料工藝
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Feng Yan , Wang Richu , Yu Kun
2007, 36(10):1820-1823.
Abstract:The nickel based self-lubricating materials containing different contents of BN were prepared by not-pressing technology of powder metallurgy. The morphologies of worn surfaces and the fracture were analyzed by scanning electron microscopy and metallurgical microscope. The influences of different hot-pressing temperature and contents of BN on mechanical and tribological properties of the material were studied. The results showed that increasing of hot-pressing temperature leaded to good mechanical properties and tribological properties of material as well as the decreasing of porosity. The Ni-Cr/10%BN had worse tribological properties compared with Ni-Cr/11%BN because decreasing of content of BN cannot form continuous lubricating film on the friction surface or the flaking lubricating film can not be supplied on time.
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Zhou Wei , Chen Jun , Zhao Yongqing , Qu Henglei , Feng Liang , Guo Dizi
2007, 36(10):1824-1826.
Abstract:對不同變形量的合金絲進行了再結(jié)晶退火試驗。根據(jù)Arrhenius公式計算出再結(jié)晶激活能Q＊結(jié)果表明，TaTi合金的再結(jié)晶速率隨變形的增加而增大，這種情況是由于再結(jié)晶形核激活能（Q）的降低所致。
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2007, 36(10):1827-1830.
Abstract:Lanthanum oxide was introduced to molybdenum powder by liquid-liquid doping and liquid-solid doping, respectively. Mo-La2O3 alloys were prepared by powder metallurgy technology. The particle size distribution and feature of doped particles were investigated by SEM and TEM. The distribution of doped particles in matrix was analyzed, the tensile property of the molybdenum alloy wire was tested, the mechanism of the influence of La2O3 particle on tensile property of Mo-La2O3 alloys was discussed by dislocation pile-up theory. The results show that liquid-liquid doping method can refine La2O3 particles and makes them dispersed uniformly in matrix. The tensile property of the molybdenum alloy wire with 0.6 mm diameter liquid-liquid-doped is better than that liquid-solid-dopinged.
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He Yushi , Wang Liang , Yuan Xianxia , Liao Xiaozhen , Ma Zifeng
2007, 36(10):1831-1834.
Abstract:分別采用混合氫氧化物法和溶膠．凝膠法制備了三元的鋰離子電池LiNi0．4Co0．2Mn0．4O2正極材料。采用XRD，SEM以及BET等方法對正極材料進行表征，并對其電化學性能進行測試。實驗結(jié)果表明，不同的合成方法和工藝條件導致了材料的晶相結(jié)構(gòu)、表觀形貌、比表面積以及電化學性能上的差異。LiNi0．4Co0．2Mn0．4O2正極材料中出現(xiàn)的陽離子相互占位將導致其電化學性能變差。與溶膠．凝膠法制備的樣品相比，混合氫氧化物法制備的樣品具有較高的比表面積（3．2m2／g）和較高的放電比容量。在充放電電壓范圍為2．5～4．3V、充放電電流為20mA／g條件下，混合氫氧化物法所制備樣品的首次放電比容量為180．1mAh·g^-1，20次循環(huán)后放電容量為160．2mAh·g^-1，并顯示出較好的循環(huán)穩(wěn)定性。
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Wang Kuaishe , Wang Xunhong , Su Xiaoli , Xu Kewei
2007, 36(10):1835-1838.
Abstract:Friction and wear performances were investigated using gas tungsten arc welds and the friction stir welds of LF2 aluminum alloy, and three sorts of revolution speeds, e.g. 480, 1200, 2400 r/min were adopted. The result showed that the friction stir weld showed much better wear-resistance performance than the gas tungsten arc welds under the same condition. There was almost no difference of wear mass loss at 480 r/min. The wear mass loss of friction stir welds was about 4~6 times less that of the gas tungsten arc welds at the other two speeds. The morphologies of the surfaces of worn welds were observed, it was found that the surface of gas tungsten arc welds presented plough ditch and spalling, and the friction stir welds presented mild fatigue wear.
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Zhang Shuangyin , Lin Xin , Chen Jing , Zhang Fengyin , Huang Weidong
2007, 36(10):1839-1843.
Abstract:通過改變激光快速成形過程中激光功率、掃描速度、搭接率、Z軸增量AZ等工藝參數(shù)，研究了各工藝參數(shù)對Ti-6Al-4V合金組織及成形質(zhì)量的影響規(guī)律。結(jié)果表明：隨著激光功率尸的提高，柱狀晶的長度逐漸變短并轉(zhuǎn)變?yōu)轭愃频容S晶的不規(guī)則晶粒；在相同的激光功率下，柱狀晶的尺度隨著激光掃描速度礦的增加變得細且長；當P／V值大于933W·s／mm時，晶粒呈現(xiàn)等軸晶形態(tài)。存在一個臨界搭接率，當搭接率為30％時，成形件內(nèi)部組織基本質(zhì)量良好，只是在靠近基材區(qū)域有少量的熔合不良；如搭接率小于30％，兩相鄰熔覆道之間的搭接區(qū)將出現(xiàn)形狀不規(guī)則的熔合不良現(xiàn)象。另外，△Z過小會造成重熔深度變大，層與層的結(jié)合處組織粗大；△Z過大時會造成層間熔合不良。
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Zhang Taiwei , Zhang Lu , Yang Shengchun , Yang Zhimao , Ding Bunjun
2007, 36(10):1844-1847.
Abstract:Silver nanocubes synthesized by hydrothermal-Induced method were prepared into substrates using two different methods. The morphologies of these two substrates were different from each other. On one substrate, the nanoparticles congregated into congeries which were monodisperse, but another was a continuous film. SERS activities of silver substrates were detected by using RhB as probe molecule The results showed that the former has better SERS activity. The mechanism of SERS effect was also discussed.
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Chen Weidong , Han Lin , Zhang Li , Huang Yongzhang , Wang Lijun , Chen Song
2007, 36(10):1848-1850.
Abstract:采用原位氧化法在氫化鋯表面制備了氫滲透阻擋層，分析了工藝參數(shù)對氧化層生長的影響，借助XRD，XPS，SEM等分析測試手段對氧化層的物相組成和截面形貌進行分析，并對氧化層的阻氫效果進行檢測。結(jié)果表明，氧化層的質(zhì)量增量隨氧化溫度的升高而增大，在氧分壓為0．1MPa，550℃恒溫氧化2h的工藝條件下，在氫化鋯表面制得了厚度為50～60um的氧化層；該氧化層主要為Baddeleyite結(jié)構(gòu)的ZrO2；氧化層中含有O，Zr，C等元素并存在O-H鍵；氧化層均勻、致密，具有一定的阻氫作用。
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Research and Application of the Catalyst Assemblies for NOx Selective Catalytic Reduction by Ethanol
Dong Hongyi , Shuai Shijin , Li Rulong , Wang Jianxin , He Hong , Shi Xiaoyan
2007, 36(10):1851-1855.
Abstract:為了解決富氧條件下NOx排放問題，在發(fā)動機臺架上對以乙醇作為還原劑時Ag／Al2O3的特性進行了實驗研究，同時對Ag／Al2O3＋Cu／TiO2和Ag／Al2O3＋Cu／TiO2＋Pt／TiO2兩種組合催化劑降低NOx的效果進行了對比分析。研究表明：Ag／Al2O3具有很好的NOx去除活性；與Ag／Al2O3＋Cu／TiO2相比，Ag／Al2O3＋Cu／TiO2＋Pt／TiO2催化劑組合具有更好的去除NOx并抑制THC和CO排放升高的綜合性能。將Ag／Al2O3＋Cu／TiO2＋Pt／TiO2應用在實驗發(fā)動機上，在EurolHESC工況下取得了64％的穩(wěn)態(tài)Nq轉(zhuǎn)化效率，并保持THC和CO排放基本不變。另外，本文也分析了組合催化劑對微粒（PM）各組分的影響。
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Wu Yanj un , Wang Dahui , Luo Yongchun , Kang Long , Yan Ruxu
2007, 36(10):1856-1860.
Abstract:The hydrogen storage alloys were prepared using induction melting followed by heating treatment and melt spun. The effect of melt spun on the phase structure, microstructure and electrochemical properties of La2Mg0.9Ni7.5Co1.5Al0.1 was investigated systematically XRD analysis shows that the obvious change of the phase composition of the La2Mgo.gNi7.5Co1.5Al0.1 alloy took place with the increase of quenching rate. The annealed alloy consists of aLa2Ni7 main phase with Ce2Ni7 type structure and a little LaNi3 second phases with PuNi3 type structure. With the increase of quenching rate, the LaNis phase with CaCus type structure and LaMgNi4phase with MgCu4Sn type structure appear in the alloys, the content of the new phases increases but the content of aLa2Ni7 phase and LaNij phase decreases. EPMA analysis indicates that the La2Mg0.9Ni7.5Co1.5Al0.1 alloys prepared by melt spun have fine columnar crystal structure. The electrochemical measurement shows that the quenching rate has little effect on the activation property but the maximum discharge capacity and the high rate discharge ability decrease with the increase of quenching rate. It has a little improvement of the cyclic stability at the lower quenching rate as 5m/s, but the alloy electrode demonstrates better cyclic stability with the further increase of quenching rate as 20 m/s
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Zeng Shengnan , Liu Jiaxiang , Zhang Nan
2007, 36(10):1861-1864.
Abstract:以金屬銦和結(jié)晶四氯化錫為原料，采用溶膠．凝膠工藝，用浸漬提拉法在石英玻璃基體上制備ITO透明導電薄膜。采用XRD，AFM，四探針電阻率儀，紫外分光光度計對薄膜的晶型結(jié)構(gòu)，表面形貌，方電阻和透光率進行了測定和分析，研究了熱處理溫度和提拉層數(shù)對薄膜光電性能的影響。結(jié)果表明：隨著熱處理溫度的升高，薄膜的方電阻顯著降低，透光率也不斷增大，但是當后處理溫度大于750℃時，透光率略有降低，方電阻仍然降低。
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Liu Shibin , Wang Xiuguang , Hao Xiaogang , Zhang Zhonglin , Duan Donghong , Sun Yanping
2007, 36(10):1865-1869.
Abstract:采用脈沖電沉積法制備Pt—Ru．Eu／C電催化劑，循環(huán)伏安法（cv）測定催化劑的甲醇電氧化活性，用XRD，EDS和XPS表征電極及催化劑的物性結(jié)構(gòu)、表面元素組成和價態(tài)形式。結(jié)果表明，電催化劑中Pt-Ru-Eu以合金的形式存在，在合金表面存在EuOx；合金微粒比表面積為55．8m^2．g^-1，粒徑為4．6nm；摻雜適量稀土金屬Eu對Pt．Ru合金活性有一定的促進效應，其中原子比為Pt：Ru：Eu=1：1：0．2時電催化活性較高。原子比過高則Pt-Ru-Eu活性低于Pt-Ru；在摻雜少量Eu時，Pt—Ru—Eu與Pt—Ru的Tafel常數(shù)b相近，常數(shù)a以Pt：Ru：Eu=1：1：0．2最?。患状挤磻墧?shù)為0．12級，反應活化能為28.3kJ·mol^-1。
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Qin Liang , Tao Jie , Wang Ling , Tao Haijun
2007, 36(10):1870-1873.
Abstract:In order to improve the electrocatalytic activities of the Ti/TiO2 electrode, the nanotube TiO2 film was fabricated by anodic oxidation on TA1 samples, and then Ti/TiO2-Pt modified electrode was prepared through the deposition of Pt on the film. The compositions, crystal structures and surface morphologies before and after depositing were characterized with the aid of X-ray and FESEM. The results showed that Pt was deposited preferentially on the edge of the nanotube ostiums. The cyclic voltammetry and stationary current-potential curves indicated that the electrocatalytic activities of the Ti/TiO2 electrode of deposited Pt were improved evidently.
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Wang Zhong , Tian Wenhuai , Li Xingguo
2007, 36(10):1874-1877.
Abstract:采用直流電弧等離子體方法合成了硅與氮化鈦納米復合材料，利用XRD，TEM等手段研究了其微觀結(jié)構(gòu)。結(jié)果顯示，得到的納米顆粒由Si和TiN以及部分Cu0．1Si1.9Ti組成，其形狀為球形，顆粒尺寸大多分布在10～50nm之間。用恒流充放電的方法研究了其作為鋰離子電池負極的電化學行為，在鋰的嵌入硅鎳納米顆粒的過程中，Si充當活性中心，而其中的TiN和Cu0.1Si1.9Ti作為惰性成分，不與Li反應，充當緩沖基體及導電劑的作用。當電流密度為150mA·g^-1時，電極的循環(huán)穩(wěn)定性最好，首次可逆容量為737mAh·g^-1，20次循環(huán)后容量仍為542mAh·g^-1。在O．05～0．8V的電位區(qū)間的循環(huán)穩(wěn)定性是最好的。
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Duan Hongzhen , Lin Xiangyang , Xu Lei , Liu Guanpeng , Guo Xiaode , Li Fengsheng
2007, 36(10):1878-1880.
Abstract:采用還原反應制備了約15nm的鈷硼（COB）金屬粉，為了防止納米金屬粉在空氣中被氧化，通過化學置換反應制備了銀包納米CoB（Ag-CoB）的納米核殼金屬粉，其形貌與組成分別通過電子透射顯微鏡（TEM）與X射線衍射（XRD）進行表征。對納米金屬粉（Ag-CoB）與未包銀的CoB金屬粉的抗氧化性通過熱重分析進行了對比，另外，利用差熱分析對兩種金屬粉對高氯酸銨（AP）的催化熱分解作用進行了比較。結(jié)果表明：（Ag-CoB）金屬粉的抗氧化效果好；納米CoB金屬粉和包銀后的Ag-CoB金屬粉對AP的催化效果都較好，經(jīng)過包銀后的Ag-CoB金屬粉對AP的催化效果明顯好于未包銀的金屬粉，達到了包覆的目的。
