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1.
通过磁控溅射的方法在石英衬底上沉积了Au薄膜,经过热退火处理形成了不同表面形貌和尺寸的Au纳米颗粒。通过XRD、AFM和紫外可见光谱研究了薄膜的质量、表面形貌、尺寸和光谱特性,分析了不同表面形貌和尺寸的Au纳米颗粒对局域表面等离激元共振的影响。研究表明:随着退火温度的升高,Au薄膜由各向异性的蠕虫状结构逐渐变成规则的纳米颗粒,退火温度越高,Au纳米颗粒越接近于圆形,颗粒间距越大,导致局域表面等离激元共振峰位发生蓝移,半峰宽变窄;另外溅射时间对Au纳米颗粒的影响也很大,随着溅射时间的增加,颗粒尺寸变大,变得不再均匀,局域表面等离激元共振峰发生红移、宽化和向长波段上扬。  相似文献   

2.
纯铜热喷涂扩散渗铝层的显微组织   总被引:1,自引:0,他引:1  
铜铝合金具有很好的抗高温氧化性能.在纯铜表面分别电 弧喷涂15mm和25mm厚的铝涂层,经900?℃保温4?h的扩散处理后获得19mm和36mm厚的铜铝合金渗层.主要针对渗层显微组织、渗层内的成分分布以及渗层的物相构成进行观察与测定.分析结果表明:渗层由表面层和内层两部分组成,层间结合良好.在加热处理过程中,铝涂层发生熔化,基体中的铜原子进入铝熔体形成表面渗层,表面渗层中遗留了原涂层的氧化物和孔洞.铝原子向铜基体的扩散形成组织紧密的内扩散层.内、外渗层都由金属间化合物Cu9Al4与αCu固溶体二相结构组成.在同样的扩散处理条件下,试件喷涂的铝涂层越厚,形成的渗层厚度越大,渗层中平均  相似文献   

3.
为了获得铜铝复合板在压应力作用下的腐蚀规律,采用螺栓加载方式令铜铝复合板承受不同程度压应力,利用盐雾腐蚀箱对不同压应力下的铜铝复合板进行了腐蚀实验,采用扫描电镜、能谱仪和X射线衍射仪对腐蚀形貌与产物进行了分析,研究了盐雾条件下压应力对铜铝复合板腐蚀形貌、腐蚀失重、腐蚀产物和电化学腐蚀性能的影响,并分析了压应力作用下铜铝复合板的腐蚀机制.结果表明:施加压应力后铜铝复合板腐蚀得到抑制,其腐蚀程度与压应力大小有关.在弹性变形区间内,存在一个压应力最佳值.压应力通过改变界面优先腐蚀倾向影响复合板腐蚀行为.压应力引起塑性变形时,应力释放可以减轻复合板腐蚀程度.铜铝复合板盐雾腐蚀条件下的腐蚀产物为Al2O3、Al(OH)3和AlO(OH).  相似文献   

4.
评述局域表面等离子体最新研究进展,介绍近年来在金属纳米颗粒和纳米结构的表面等离子体光学理论和实验研究上取得的一些成果,包括银纳米粒子的制备以及不同形状、尺寸等因素对局域表面等离子体光谱的影响、表面等离子体共振放大拉曼散射的增强、等离子激光、等离子非线性效应及局域表面等离子光热效应等.探讨表面等离子体光学结构在纳米尺度上对光的各种性质的调控以及局域表面等离子体在纳米生物光子学方面的新应用.  相似文献   

5.
针对连铸过程浸入式水口的堵塞情况,研究了铝锆碳复合浸入式水口堵塞的形成机理.堵塞沉积主要是由于氧化物颗粒附着到浸入式水口耐火材料的内表面,继而烧结存一起所致.  相似文献   

6.
针对碎片尺寸和形状会影响岩石强度和变形的问题,采用三维扫描技术获得真实岩石颗粒的表面点云数据,然后通过数字图像处理技术重构数字颗粒,利用连续-离散耦合方法(FDEM)模拟单个颗粒在平板压缩下的断裂破碎. 识别颗粒破碎后所产生的碎片,并进行碎片形状的表征和量化,分析碎片形状与颗粒初始形状、碎片尺寸的关系. 为了准确描述裂纹尖端的应力梯度和损伤演化,进行颗粒有限元网格密度的敏感性分析,结果表明,断裂过程区至少需要5、6个界面单元以减弱网格尺寸的影响. 本研究关注颗粒破碎后所产生碎片的整体形态,忽略断裂引起的碎片表面局部起伏和粗糙变化. 尽管所研究颗粒的初始形状存在较大差异,仍发现颗粒破碎后所产生碎片的形状指标分布具有一些共性特征. 碎片的圆度、扁平率、Domokos因子和凸度对颗粒初始形状的敏感性逐渐增强,并且除了圆度外,其他形状指标分布与碎片尺寸之间并未发现显著的相关性. 不同粒径组碎片的圆度分布表明,较大的碎片棱角更明显.  相似文献   

7.
利用化学气相沉积技术对碳化硼颗粒表面进行改性,X-射线衍射证实在碳化硼颗粒表面形成碳化铬和硼化铬混合物的薄膜,利用电沉积技术制备了Ni-W-Co-B4C(CVD)表面复合材料,油润滑条件下的磨损实验结果表明B4C颗粒的表面改性取得了良好效果,B4C(CVD)颗粒与表面金属结合紧密。  相似文献   

8.
颗粒形状对铝基复合材料热残余应力影响的有限元分析   总被引:3,自引:0,他引:3  
通过复合材料显微组织观察,建立了平面应力状态的复合材料组织模型,利用有限元方法对Al2O3p/2024Al复合材料和SiCp/2024Al复合材料淬火过程的热应力进行了数值模拟,研究了颗粒形状对铝基复合材料淬火处理过程下热残余应力的影响.结果表明,由于增强颗粒与铝基体之间的热膨胀系数差异较大,淬火处理后颗粒和基体的界面附近产生很大的热残余应力场,同时基体发生塑性应变.  相似文献   

9.
在室温条件下先用直流溅射的方式在丙纶非织造布表面沉积铜膜,再用射频磁控溅射法在铜膜表面沉积氧化锌薄膜形成层状膜,借助X射线能谱仪(EDX)、扫描电子显微镜(SEM)、原子力显微镜(AFM)和X射线衍射(XRD)观察薄膜结构,通过改变氩气流量研究其对织物紫外线透过率的影响.实验结果表明,随着氩气流量的增加,纳米薄膜颗粒先增大后缩小,紫外线透过率也先升高后降低,在氩气流量为40 mL/min时,紫外线透过率最低.  相似文献   

10.
采用真空离子镀膜机在SiO2玻璃基片表面分别蒸镀Cu和Al薄膜,3组参数6次制备12个铝或铜薄膜试样.实验表明:相同工艺条件下,铝膜较铜膜附着力更强,膜厚更大,更易形成薄膜且结构均匀致密.经测试可知:当铝膜的轰击电压为175V,烘烤电压为160V,蒸镀时间为2h、铜膜的轰击电压为200V,烘烤电压为100V,蒸镀时间为1.8h,制得的样品纯度高,杂质含量少,微观结构与膜厚最理想,界面结构规范,平滑,吸附力强,薄膜界面微观粗糙性和形状较佳.  相似文献   

11.
1 IntroductionElectrodeposition,has been widely usedin electron-ics, automobile and airliner industry, and has been anobject of intense research over the past years . Comparedwith other methods for preparing coatings ,the electro-deposition has several advantages , such as least cost ,controllability, avoidance of thermal stress and higherproduction, which can produce functional coatings withresistance to corrosion and wear and low coefficient offriction in engineering field[1 ,2]. Moreover ,t…  相似文献   

12.
The nucleation process of graphene films prepared by pulsed laser deposition has been investigated in detail. It is found that graphene nucleates at the steps on the substrate surface firstly, from aggregation of nuclei into particles. High pulsed laser energy offers large incident energy for carbon particles deposited on the surface of the substrate, which is beneficial to the nucleation of graphene. A lot of steps are formed on the copper substrate due to the high temperature, so that the high incident energetic carbon species are able to form a stable nucleus at the steps. As the incident particles increases, the graphene nuclei are combined to grow together. Further, it is found that graphene tends to form few layer graphene particles instead of large graphene sheets.  相似文献   

13.
Growth behavior of electroless copper on silicon substrate   总被引:1,自引:1,他引:1  
The growth behavior containing deposit morphology, growth rate, activation energy, and growth mechanism of copper on silicon substrate, especially at the initial stage, in the electroless plating process was studied. Copper was deposited on the surface of the silicon substrate in an electloless plating bath containing formalin (CH2O 37vol%) as a reducing agent at a pH value of 12.5 and a temperature of 50-75℃. The copper deposit was characterized using a field emission scanning electron microscope and transmission electron microscope. The results showed that after the activation process, nanoscale Pd particles were distributed evenly on the surface of the silicon; in the deposition process, copper first nucleated at locations not only near the Pd particles but also between the Pd particles; the growth rate of electroless Cu ranged from 0.517 nm/s at 50℃ to 1.929 nm/s at 75℃. The activation energy of electroless Cu on Si was 52.97 kJ/mol.  相似文献   

14.
用不同铜盐制备大小均匀、平均粒径分别为70nm和200nm的菱形氧化铜粒子,并对影响粒子大小、形状的诸因素进行了探讨。  相似文献   

15.
Gold(Au) nanoparticles were prepared on Au-fi lm-coated K9 glass and silicon substrates by direct current(DC) magnetron sputtering and thermal annealing treatment. The effects of substrate material, annealing temperature, and time on morphologies of Au nanoparticles were investigated, and the formation mechanism of Au nanoparticles was discussed. The experimental results indicate that silicon substrate is more suitable for the formation of Au nanoparticles. On a silicon substrate, Au nanoparticles formed with good spherical shapes at temperature over 700 ℃. It was also found by spectral analysis that the fi eld enhancement factor of the island-shaped Au particles was smaller than that of the granular Au particles; the better the spherical shape as well as the smaller the size and spacing of Au particles, the higher the light absorption rate; the absorption peak had a red shift with increasing particle size and spacing.  相似文献   

16.
The process of Sb2Te3 thin film growth on the Pt substrate by electrochemical atomic layer epitaxy (ECALE) was studied. Cyclic voltammetric scanning was performed to analyze the electrochemical behavior of Te and Sb on the Pt substrate. Sb2Te3 film was formed using an automated flow deposition system by alternately depositing Te and Sb atomic layers for 400 circles. The deposited Sb2Te3 films were characterized by XRD, EDX, FTIR and FESEM observation. Sb2Te3 compound structure was confirmed by XRD pattern and agreed well with the results of EDX quantitative analysis and coulometric analysis. FESEM micrographs showed that the deposit was composed of fine nano particles with size of about 20 nm. FESEM image of the cross section showed that the deposited films were very smooth and dense with thickness of about 190 nm. The optical band gap of the deposited Sb2Te3 film was determined as 0.42 eV by FTIR spectroscopy, and it was blue shifted in comparison with that of the bulk Sb2Te3 single crystal due to its nanocrystalline microstructure.  相似文献   

17.
Ti/Cu/N coatings with different Cu contents were deposited on titanium alloy surface by the DC magnetron sputtering technique.XPS and FESEM were employed to characterize the composition and structure of the coating on the Ti6A14 V substrates.In addition,The adhesion force,friction,and wear properties of the Ti/Cu/N coatings were investigated.The experimental results showed that the coarse particles of the coatings would grow more and the surface roughness increased with the increase of copper content in the coatings;The coatings showed a strong adhesion force;The friction coefficient of the coating of the samples was less than the substrate,reaching 0.19 at least.The wear resistance of the coatings could be improved by optimizing and controlling the relative content of Ti,Cu,N elements on the titanium alloy surface,especially the 10.98 at%contents of the copper.The sample C2 kept the best wear resistance.  相似文献   

18.
研究了制备氧化铜均分散的超微粒子的条件,发现pH、阴离子、温度等均与此有关。用不同方法研究了粒子形成过程及内在的化学机理。在实验室条件下,制备出各种形状、大小的氧化铜粒子,从中得到一些规律。  相似文献   

19.
研究了焙烧对物理法制备的纳米铜催化剂的影响规律。结果表明,焙烧不同程度地降低纳米钢催化剂的活性,高温焙烧时生成了 CuAl2O4,纳米钢粒子在载体上的分散度影响焙烧后催化剂活性的变化。  相似文献   

20.
用磁控溅射SiO2膜作为台面SiGe/SiHBT的表面保护纯化膜和光刻掩膜.测试分析了溅射工艺对SiO2膜的性质和SiGe/SiHBT性能的影响.研究发现,较高的衬底温度(200℃)有得于改善SiO2膜的质量.用溅射SiO2方法制备的HBT的电流增益明显高于用热分解正硅酸乙脂方法淀积SiO2制备的HBT.这说明溅射法避免了高温引起SiGe层应变驰豫所造成的HBT性能变差.  相似文献   

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