金属火灾熔痕的显微组织及物相成分的实验研究

利用X-射线衍射(XRD)和3D图像处理软件(Image-pro)研究了四种不同火灾类型金属熔痕的显微组织、平均晶粒度、物相组成及其分布规律。结果表明：金属火灾熔痕主要由立方晶系的Cu₂O和胞、枝状的Cu组成。在四种不同的起火方式下,金属熔痕的显微组织和成分有显著的差别：(1)一次短路的火灾熔痕平均晶粒度为3～5 μm,其Cu₂O含量最低;过载熔痕的平均晶粒度与一次短路的类似,但其Cu₂O含量为30%左右;(2)二次短路熔痕中含有一定数量直径较大的微观空洞,平均晶粒度约为30 μm;其Cu和Cu₂O衍射峰出现展宽和辟裂,烧蚀程度最深;(3)火灾熔痕中粗大的Cu₂O等轴晶衍射峰强度最大,且显微组织中几乎没有微观空洞存在。     

柔性ITO衬底电化学沉积制备Cu/Cu2O薄膜

研究了使用电化学沉积法于碱性条件下在柔性ITO衬底上制备Cu/Cu₂O薄膜的方法。循环伏安曲线表明Cu₂O与Cu的阴极峰分别位于-500 mV(vs Ag/AgCl)和-800 mV(vs Ag/AgCl)附近。利用循环伏安法考察了生长温度和电解液pH值等对Cu₂O与Cu阴极峰电位的影响,阴极峰随生长温度的升高以及pH值的降低而略向阳极移动,沉积电流也随之相应增大。与弱酸性条件相比,上述两个阴极峰随pH值升高而移动的程度明显减小,这可能与碱性条件下C₃H₆O电离程度增大以及C₃H₆O根作为配体的过量程度有关。通过X射线衍射光谱和扫描电子显微镜的表征证实,在所研究的生长温度区间和pH值内可利用电化学沉积法在柔性ITO衬底上制备Cu/Cu₂O纳米混晶薄膜。在相同的生长温度和pH条件下,电化学沉积电位对样品表面形貌和晶体性质具有较大影响。     

拉曼光谱分析青铜器本体中锈蚀产物

青铜器锈蚀研究能够揭示出青铜器腐蚀机理,为制定科学的保护措施提供重要的参考资料。目前,青铜器锈蚀研究主要从其外部锈蚀产物入手,通过锈蚀组成结构分析,探讨其腐蚀机理。本文选择了保存较好青铜器本体样品进行了内部锈蚀情况研究。首先采用金相制备技术,通过打磨、抛光和超声清洗处理后,制备了断面相组织形态清晰的24件秦早期青铜器青铜本体样品。然后利用共聚焦显微拉曼光谱仪对样品夹杂物进行了光谱学研究,发现其物相为PbCO₃和PbO及Cu₂O,都属于常见的青铜合金腐蚀产物。样品金相组织中圆形或者大面积无规则亮灰色区域为Cu₂O,反映出青铜器表面不仅易于形成一定厚度Cu₂O锈蚀层,在相界之间也容易发生氧化反应生成Cu₂O,存在合金内部和外部同时发生腐蚀生成赤铜矿锈蚀的情况。此外,拉曼光谱分析显示黑灰色物质主要为铅腐蚀产物——PbCO₃和PbO,反映出铅元素的腐蚀过程：Pb→PbO→PbCO₃。在铸造态青铜合金组织中,铅一般呈近圆形颗粒状态分布在相界之间。青铜器内部分布的铅颗粒在土壤埋藏环境中会发生氧化反应生成PbO,再与地下水中溶解的CO2-₃发生化学反应生成比较稳定的PbCO₃。结果表明：外界腐蚀因素(水、溶解氧和碳酸根等)能够通过合金中相界间通道进入青铜器内部,在相界表面逐步发生反应形成以金属氧化物为主的腐蚀产物。     

采用深度刻蚀与XPS能谱研究缓蚀膜/镀铜层/铁基体界面成分

为了探索焦磷酸盐镀铜层与铁基体结合强度差的原因,采用波谱技术,分析了纵向界面各种元素的成分变化,讨论了金属基体表面粗糙度对元素分布的影响.根据刻蚀时间可将膜层分为三部分:N,O量迅速减少的表面层,有基本固定组成的中间层和占一半厚度的出现基体元素的混合干扰层.通过对后期混合层中氧含量的分析,可得出镀铜层/铁基体界面含氧层的存在是影响电镀层与基体结合强度的主要原因的结论.     

采用AES深度刻蚀研究不同氧气含量下短路熔痕的成分

火灾中短路发生时周围的环境气氛对短路时导线上形成的熔化痕迹特征具有决定性影响。为了探讨环境气氛中氧浓度对短路熔痕特征的影响,文章对木材、纸板、泡沫、橡胶、塑料等典型燃烧物燃烧时燃烧部位的氧气浓度进行了测定,确定了典型燃烧物燃烧时燃烧部位氧气浓度的极限条件。选择100% N₂, 10% O₂+90% N₂和20% O₂+80% N₂三种浓度的试验气体,分别在3种气体环境下进行短路实验,然后对得到的短路熔痕样品进行AES深度剖析,得出短路熔痕样品表层平均氧含量与环境氧浓度成近似线性的对应关系。因此可以根据测得的氧浓度,确定出短路发生时的周围环境气氛条件,推断其与火灾发生的关系,进一步推断火灾原因。     

常见氯盐溶液水的拉曼包络线高斯-洛仑兹去卷积分峰定量研究

为了探索地质流体中常见阳离子的拉曼光谱定量方法, 在室温下对NaCl-H₂O, CaCl₂-H₂O, MgCl₂-H₂O, CuCl₂-H₂O, ZnCl₂-H₂O和FeCl₃-H₂O体系3 000～3 800 cm-1范围水的O—H伸缩振动区域进行了高斯-洛仑兹去卷积分峰,并对所得积分参数进行了分析。结果显示：(1)不同体系拟合后参数比(峰强比、半高宽比和积分面积比)与浓度的线性相关程度不尽相同,但对于所有体系来说拟合峰强度比(低频/高频)与浓度的线性关系均很好,完全符合定量要求,为室温下定量分析这些体系盐溶液,提供了一种便捷、可靠的定量方法。(2)拟合峰的强度比(低频/高频)随浓度的变化,在NaCl-H₂O,CaCl₂-H₂O和MgCl₂-H₂O体系中,随浓度增加,强度比呈下降趋势,说明分子间氢键逐渐减少;然而在CuCl₂-H₂O,ZnCl₂-H₂O和FeCl₃-H₂O体系却是呈上升趋势,说明分子间氢键逐渐增多,可能与这三个体系均是过渡金属离子氯盐在水中形成络合物作用有关,尚需进一步研究。(3)通过各个体系强度比与浓度关系一次拟合曲线斜率可以看出对水分子氢键的影响能力CaCl₂和MgCl₂＞NaCl;FeCl₃＞ZnCl₂和CuCl₂。     

反射光谱装置及定量分析设计

设计了一种反射光谱测量装置。该装置由光纤传导并用于定量分析。通过测定还原糖与斐林试剂反应生成的Cu₂O,建立测定还原糖的反射光谱分析方法。还原反应在微型反应池中进行,生成鲜红色Cu₂O,光纤探头直接测定降于池底的沉淀。探讨了该方法的基本原理、影响因素及测定条件。该方法具有操作方便,灵敏度高,试剂用量少等优点。还原糖在20～120 μg范围内呈良好的线性关系,用于实际样品测定,结果满意。     

激光熔覆原位合成Nb(C,N)陶瓷颗粒增强铁基金属涂层

采用预涂粉末激光熔覆技术,在42CrMo基体上制备出原位合成Nb(C, N)颗粒增强的铁基复合涂层。X射线及扫描电镜分析结果表明:激光熔覆获得的涂层基体为耐氧化、耐蚀性良好的Fe-Cr细晶组织及少量的-Fe相,原位合成的Nb（C, N）呈块状弥散分布在基体上。进一步的磨损试验表明:这些颗粒增强相极大增强了抗磨损性能,与未熔覆的母材相比,其磨损失重仅为母材的1/9左右; 涂层在750 ℃恒温氧化条件下具有较好的抗氧化性能,氧化层主要由NbO1.1,Cr2O3相组成; 母材的氧化产物为Fe2O3,容易脱落,保护性能较差; 激光熔覆涂层的氧化膜厚度仅为未涂层的1/5。     

β-SiC薄膜在SF6和SF6+O2中的等离子体刻蚀研究

以SF₆和SF₆+O₂为刻蚀气体,采用等离子体刻蚀工艺成功地对化学气相淀积工艺制备的β-SiC单晶薄膜进行了有效的刻蚀去除.实验指出当气体混合比约为40%时,刻蚀速率达到最大值.俄歇能谱分析表明,在SF₆和SF₆+O₂气体中被刻蚀后的样品没有形成富C表面的SiC层.研究结果为各种SiC器件的研制奠定了必要的实验基础. 关键词：     

非晶熔石英表面等离子体刻蚀过程 中的表面晶化研究

本工作采用电子回旋共振(ECR)低压等离子体刻蚀技术, 刻蚀非晶熔石英表面. Ar/CF₄为反应气体刻蚀后再经O等离子体钝化, 非晶熔石英表面出现晶化现象. 晶化层约几百纳米厚. Ar/CF₄在ECR的电磁场作用下产生F离子与C离子, F离子使熔石英表面的Si-O共价键断裂, 并释放出O离子. C离子与O离子迅速键合生成CO₂, 而被断键的Si原子与四个F原子键合生成气态SiF₄. 熔石英原始表面被去除的同时, 在新的表面留下大量不饱和Si原子. 不饱和Si原子在高温条件下被O等离子钝化, 形成结晶态α 方石英.     

Characterization of oxide layers on amorphous Zr-based alloys by Auger electron spectroscopy with sputter depth profiling

Amorphous Zr-Cu-Ni-Al-[Ti, Nb] ribbons prepared by melt spinning under argon atmosphere were subjected to electrochemical investigations. Passive films developed at potentiostatic anodic polarization in sulphuric acid solution were investigated by Auger electron spectroscopy (AES) and sputter depth profiling.Changes in the shape of the Auger peaks have been analyzed by factor analysis of the spectra obtained during depth profiling. Pronounced changes in shape and position occur for the Zr, Al, and Ti Auger transitions, but not for Cu and Ni. At least three different peak shapes for O(KVV) were found and attributed to different oxygen binding states. The alloy composition has no significant effect on the thickness and composition of the oxide layer.In multi-element alloys preferential sputtering is a common phenomenon. In the steady state of sputtering, a significant depletion in Cu is found. At the oxide/metal interface, a distinct enrichment of copper is found for all alloys and treatments. The degree of this Cu enrichment depends on the pretreatment. It is higher for the electrochemically-passivated samples than for samples with oxide layers grown during melt spinning.     

Investigation of the compositional changes of a Y-Ba-Cu-O HTSC target under ion sputtering

An Auger electron spectroscopy study is reported of the elemental depth profile of Y-Ba-Cu-O HTSC targets subjected to ion-plasma sputtering in a magnetron deposition system and ion-beam sputtering in the Auger spectrometer chamber. It has been established that the process consists in all cases of predominant copper sputtering accompanied by the formation of a modified surface layer and of a copper-depleted region. This region is assumed to originate from intense copper diffusion from the bulk to the modified surface layer driven by a concentration gradient.     

分子束外延GaN薄膜的X射线光电子能谱和俄歇电子能谱研究

用XPS和AES电子能谱的方法对等离子体辅助分子束外延(MBE)生长的GaN薄膜进行了表面分析和深度剖析.发现红外分子束外延(RFMBE)生长的富镓GaN薄膜实际表面存在O和C吸附层,C主要为物理吸附,而O在GaN表面形成局域化学键产生氧络合物覆盖层,并形成一定的深度分布.杂质O在GaN带隙中导带底形成杂质带同时引入深受主能级,使得带隙变窄室温光吸收谱向低能方向移动,光致发光谱出现宽带发光峰.从而影响GaN薄膜的电学和光学性质 关键词： GaN薄膜 X射线光电子能谱 俄歇电子能谱 表面分析     

Quantitative Auger analysis of gold-copper-oxygen and gold-nickel-oxygen surfaces using relative sensitivity factors

Quantitative Auger analysis is becoming routine for unoxidized binary allowys. Many specimens of technological importance, however, contain large amounts of oxygen, which can complicate quantitative analysis by changing (a) peak shapes (e.g. ] ne widths, δ), (b) energy position of the peaks, (c) Auger currents, and (d) the sputtering correction factor (R). This paper describes quantitative Auger analysis of the gold- copper-oxygen and gold-nickel-oxygen systems, based on relative sensitivity factors before (P_rel) and after (P^s_rel) sputtering. The relative sensitivity factors, (P^s_rel) were found to be independent of the gold and oxygen concentrations for both systems. In the gold-copper-oxygen system this is attributed to the sharpness of the 920 eV (LMM) copper transition compared to the energy resolution (0.6%) of the CMA analyzer used. For the gold-nickel-oxygen system it is ascribed to a fortuitous cancellation of two effects (1) increased line width, δ, hence a decreased 848 eV (LMM) peak height upon oxidation, and (2) increased Auger emission of the 848 eV peak due to oxidation. A single crystal standard of Cu₂O was used to confirm the 2 : 1 ratio of Cu to O in the ternary samples. The sputtering correction factors were found to be R(O, Cu) = 1.0 for the composition of Cu₂O and R(O, Ni) = 0.72 for the composition NiO. The variation in R with Au concentration is negligible. The major limitation on the quantitative Auger analysis of these ternary systems has been found to be uncertainty in the sputtering correction Factor R. Nomographs for calculating concentrations for constant C_o/C_Cu and C_O/C_Ni using (P^s_rel) are also presented.     

Interfacial studies of uncoated and coated NiTi particles in SnPbAg matrix

Uncoated and copper electroless coated fine NiTi superelastic particles have been incorporated into liquid SnPbAg matrix. The wettability of the Cu coating by the molten alloy was determined with a wetting balance. The composite interfaces have been investigated by Auger Spectroscopy. Uncoated NiTi reacted with the matrix to form Ni-Sn intermetallics, whereas the Cu layer of coated particles behaved as a sacrificial layer, leading to a small interfacial zone containing neither Cu-Sn nor Ni-Sn intermetallics. The mechanical characterisation of Cu-coated NiTi/SnPbAg composites shows a reinforcement of the composite material compared to the monolithic matrix, and also an unusual increase of the elongation at rupture. These results can be interpreted in terms of the superelastic properties of the NiTi SMA particles.     

A study of H2S adsorption kinetics on the clean and oxygen covered (110) surface of copper

The very low pressure adsorption kinetics of H₂S on the clean and oxygen covered Cu(110) face have been examined by Auger Electron Spectroscopy (AES) and Mirror Electron Microscopy (MEM, used for continuous surface potential variations of the copper surface). The AES experimental curves on the clean copper face have been interpreted using a model of island growth by surface diffusion. The presence of an adsorbed oxygen layer on the copper surface changes notably the induction times observed on both AES and MEM measurements.     

Characterization of doped diamond-like carbon films deposited by hot wire plasma sputtering of graphite

Diamond-like carbon (DLC) films doped with nitrogen and oxygen were deposited on silicon(100) and polytetrafluoroethylene (PTFE) substrates by hot wire plasma sputtering of graphite. The morphology and chemical composition of deposited films has been characterized by scanning electron microscopy, XPS, Auger, FTIR spectroscopy and micro-Raman scattering. Plasmon loss structure accompanying the XPS C 1s peak and electron energy loss spectroscopy (EELS) in reflection mode was used to study the fraction of sp³ bonded C atoms and the density of valence electrons. Raman spectra show two basic C–C bands around 1575 cm^-1 (G line) and 1360 cm^-1 (D line) . Auger depth profiling spectroscopy was used to measure the spatial distributions of C, N and O atoms in the surface layer of DLC films. The fraction of sp³ bonded atoms of about 40% was detected in DLC films by XPS plasmon loss and EELS techniques. Nitrile and iso-nitrile groups observed in FTIR spectra demonstrated the existence of sp bonded carbon in doped DLC films. The typical for DLC films specific density 1.7–1.8 g/cm³ was obtained from EELS and XPS data. PACS 52.77.Dq; 81.65.-b; 82.80.Pv     

Auger study of preferred sputtering on binary alloy surfaces

Auger Electron Spectroscopy has been used to investigate the preferred sputtering behavior on homogeneous Cu/Ni alloy surfaces. Measurements were made on a range of alloy compositions with Ar⁺ sputter ions of 0.5 to 2 keV energy. A kinetic model has been formulated to describe the time variation of the surface composition during sputtering. Based on this model, we were able to determine the individual sputter yields for Cu and Ni atoms in the alloy and the depth of the surface layer where the composition is altered by sputtering. The sputter yields were found to be relatively independent of the alloy composition but increased almost linearly with energy. The depth of the altered layer was comparable to the Auger sampling depth with its value increasing from 10 Å to more than 20 Å when ion energy increased from 0.5 to 2 keV.     

基于激光焊接的网络滤波器无铅化封装

 采用激光直接焊接的方法,研究网络滤波器的无铅化封装技术,通过3种不同的方式进行了实验研究和理论分析,获得了将网络滤波器中直径为0.10 mm的极细铜芯漆包线在不去除绝缘漆的情况下直接焊接到铝引脚上的方法和途径。结果表明：焊接时用激光照射铜芯漆包线,去除绝缘漆后再熔化高熔点的、流动性好的铜芯,熔化后的液态金属铜向下流动,包覆难于焊接的、流动性差、易氧化、易形成气孔等焊接缺陷的铝材引脚,然后再与铝发生溶解、扩散,最后形成良好焊点。这种不需去除绝缘漆的方法使焊接过程大大简化,且满足无铅化的要求;通过辅助电路,能在一定程度上提高焊接的可靠性,便于进行自动化。