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回顾了近年来国内外对于表面活性剂在氧化铝制备过程中的应用研究现状,结合氧化铝制备中中间产物的研究成果,综述了阴离子、阳离子表面活性剂对纳米氧化铝颗粒大小、形貌以及孔结构等的控制作用.分析了吸附机理以及各种因素如表面活性剂物性、溶液pH值、离子强度等对吸附作用的影响.在此基础上探讨了表面活性剂在该领域的应用前景. 相似文献
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采用复合电铸工艺, 在硫酸铜镀液中加入纳米氧化铝颗粒制备了纳米颗粒弥散增强铜基复合材料, 利用扫描电镜、电子透镜对复合材料的表面、拉伸断面和摩擦磨损表面的形貌以及微观组织进行了观察, 并对显微硬度、拉伸性能、磨损性能及电阻率进行了研究。结果显示, 氧化铝颗粒及其团聚体以纳米级尺寸弥散分布在铜基体中, 且与铜基体结合良好。复合材料的硬度最大增幅达42 %。氧化铝颗粒含量在1. 26 %时, 复合材料的拉伸强度和延伸率分别高达385 MPa 、26 %。相对电铸纯铜, 复合材料的耐磨性能明显提高, 而复合材料的电阻率最大增幅小于6 %。 相似文献
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在低温条件(80℃)下,以钛酸丁酯为原料,利用胶溶–回流法在氧化铝粉体表面制备了纳米TiO2颗粒.通过扫描电镜、X射线衍射、X光电子能谱仪、BET等检测手段对复合颗粒的表面形貌、包覆层相组成、比表面积等进行了表征.结果表明,纳米TiO2颗粒在微粉表面形成纳米薄膜修饰层,包覆层主要为锐钛矿型相,表面纳米化修饰后氧化铝粉体表面的粗糙度显著增加,比表面积较包覆前提高了30倍以上.将经表面纳米化修饰后的微粉应用于以有机硅改性环氧树脂为基体的耐磨涂层中,其磨损失重仅为包覆前复合耐磨涂层的55%,耐磨性显著提高,并初步讨论了复合耐磨涂层的摩擦磨损性能. 相似文献
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分别采用纳米气相氧化铝(F-Al_2O_3,平均粒径13nm)和纳米球形氧化铝(Q-Al_2O_3,平均粒径100nm)与环氧-聚酯粉末涂料熔融挤出复合,经静电涂装的方式制备环氧-聚酯纳米复合耐磨涂层。在多功能摩擦实验机上对不同填充量的两种纳米氧化铝颗粒复合涂层进行耐磨性测试,采用电子扫描显微镜观察纳米氧化铝颗粒在涂层中的分散情况,采用激光共聚焦扫描显微镜观察磨损面的形貌,并对涂层的表面粗糙度、光泽度进行测量。结果表明:F-Al_2O_3两种氧化铝颗粒都可改善涂层的耐磨性能,在相同填充量的情况下,F-Al_2O_3复合涂层的比磨损速率都低于Q-Al_2O_3体系。F-Al_2O_3颗粒质量含量为10%时,磨损速率变为纯树酯涂层磨损量的1/3;Q-Al_2O_3颗粒质量含量为30%时,磨损速率变为纯环氧-聚酯涂层的1/52。两者的颗粒都增加了涂层的表面粗糙度,F-Al_2O_3对涂层表面光泽度无影响,Q-Al_2O_3含量越高,表面粗糙度提高,光泽度下降。 相似文献
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Al2O3/Ni包裹粉体的制备、烧结行为及其显微结构研究 总被引:11,自引:0,他引:11
利用非均相沉淀包裹技术,在铝无机盐溶液中制备出氧化铝前驱体包裹纳米镍颗粒的复合粉体,并通过能量发射能谱(EDS)以及俄歇电子能谱(AES)研究包裹粉体的成分构成,发现镍纳米颗料表面均匀地包裹一层氧化铝的前驱体。燃烧后的包裹粉体在氩气氛中进行热压烧结。结果表明,与溶胶-凝胶法制备的粉体相比,包裹粉体可以在较低的温度下达到致密化,烧结后的材料其显微结构明显不同于环磨粉体烧成的材料,否认在氧化铝晶界或晶内,镍颗粒与氧化铝之间都有孔隙,这是由于镍的热膨胀系数与氧化铝的热膨胀系数大引起的,Al2O3/Ni复合材料的断裂方式以及沿晶断裂为主。 相似文献
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纳米氧化铝颗粒增强TDE-85型环氧树脂的固化动力学和力学性能研究 总被引:1,自引:0,他引:1
用超声分散法和程序温度固化制备了纳米氧化铝颗粒增强TDE-85型环氧树脂复合材料,研究了添加纳米氧化铝颗粒对环氧树脂固化动力学和力学性能的影响.根据示差扫描量热法(DSC)曲线,由Kissinger方法和Ozawa方法计算了固化体系固化反应的活化能,用Kissinger公式计算了Arrhenius指前因子,并用Crane方法计算了固化体系的反应级数.研究结果表明,添加纳米氧化铝颗粒增加了体系固化反应的活化能,但对反应级数和Arrhenius指前因子的影响较小;当纳米氧化铝添加量为1wt%(环氧树脂的质量分数)时,复合树脂的拉伸强度提高19%;伸长率提高34.5%. 相似文献
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The effect of an alumina coating, obtained by mechanofusion, on stainless-steel particles used in plasma spraying has been studied by examining sprayed particles in mid-flight and their resulting splats and coatings. The mean size of the injected powders is about 65 μm and the thickness of the alumina shell 4 μm. The results show that without preheating the substrate the splats of both types of powder are extensively fingered and become circular when the substrate surface is preheated over 200°C. For the case of the stainless steel/alumina composite splats, Energy dispersive spectroscopy (EDS) analysis of the distribution of the various elements shows that the alumina is either spread exactly on the stainless-steel splat or is dispersed in pieces and frozen over the surface of the stainless-steel splat. The first case corresponds to well molten particles where, after their flight in the plasma jet, all the alumina shell has flowed to the tail of the particle; the second case is related to particles which have still an alumina shell uniformly distributed around the stainless-steel core. Finally, a composite stainless steel/alumina coating sprayed on a rough (Ra 6.7±0.3 μm) stainless-steel substrate preheated to 400°C is compared with a pure stainless-steel coating. Both hardness and cohesion are found to improve for the alumina-coated particles. 相似文献
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为了提高氧化铝颗粒的CMP性能, 本工作探索了一种合适的改性方法。同时, 为了改善其化学机械性能, 通过与其表面羟基的硅烷化化学反应和与Al和仲胺的络合两种作用, 用N-(2-氨基乙基)-3-氨基丙基三甲氧基硅烷表面改性氧化铝颗粒。本工作给出了化学反应机理, 即N-(2-氨基乙基)-3-氨基丙基三甲氧基硅烷接枝到氧化铝表面。通过傅里叶变换红外光谱(FTIR)和X射线光电子能谱(XPS)表征了改性氧化铝颗粒的组成和结构。结果表明: N-(2-氨基乙基)-3-氨基丙基三甲氧基硅烷已被成功地接枝到氧化铝颗粒的表面, 导致改性比未改性的氧化铝颗粒具有更好的化学和机械性能。测试了未改性和改性的氧化铝颗粒在蓝宝石基底上的CMP性能。结果显示: 改性氧化铝颗粒比未改性氧化铝颗粒有更高的材料去除速率和更好的表面质量。即, 改性氧化铝颗粒在pH=10时比未改性氧化铝颗粒在pH=13.00时表现出更高的材料去除率, 这将为减少设备腐蚀提供新思路。 相似文献
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本文讨论了用超临界流体干燥混凝胶制备氧化铝超细粒子的影响因素;一类为超临界流体的影响因素.其甲温度和压力具有明显的影响,有一较台适的超临界温度达最大比表面积;但超临界压力越低,比表面积越大。加热速率几乎没有影响。另一类为制备混凝胶的影响因素,包括水解温度、加水比例.异丙醇铝固体浓度等均有一最佳制备条件。 相似文献
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This paper reported on dispersion effect and dispersing techniques of nanometer WS2 particles in the green lubricant concocted by us. And it also researched on auto-reconditioning performance of nanometer
WS2 particles to the abrasive surfaces of steel ball from four-ball tribology test and piston ring from engine lubrication test.
The treated and untreated nanometer WS2 particles were analysed by infrared spectrum. And the elementary component and interior elementary distribution of abrasive
surface repaired by nanometer WS2 particles were analysed by multifunction electron spectrometer. The results showed that the combinative method of ultrasonic
dispersion, mechanical agitation and surface modification could improve the dispersion uniformity and stability of nanometer
WS2 particles in the green lubricant effectively. And the optimal ratio of the mass between surface modifier and nanometer WS2 particles was 1: 2.5, the optimal treating time was 5 h. And IR analysis indicated that surface modifier could react with
hydroxide radicals on surfaces of WS2 particles and modify the surfaces, and the long lipophilic groups on surfaces of nanometer WS2 particles could stretch in oil adequately and form steric hindrance layers between particles which prevented particles from
conglomerating and depositing. In addition, tribological tests and surface analysis indicated that there were WS2 adsorption film and reaction film on abrasive surfaces during the tribological tests, which could fill and level up the furrows
on abrasive surfaces. As a result, the abrasive surfaces were repaired effectively by nanometer WS2 particles. 相似文献
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This study investigated the batch grinding kinetics of silicon carbide (SiC) particles in a fluidized bed opposed jet mill by population balance modeling. The selection and breakage functions were obtained by the first Kapur function method. The breakage behaviors for various SiC particles obtained under different experimental conditions (such as inlet air pressure, feed load, and distance between nozzle outlet and jet meeting point) in the jet mill were discussed. In addition, a polynomial model was proposed to predict the relation between the Kapur function and the particle size in the jet mill. The product size distributions obtained under various operating conditions from the jet mill could be simulated by modeling. 相似文献
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In this study, the subsurface microstructure of alumina wear surfaces and the microstructure of agglomerated debris generated from unlubricated sliding wear at room temperature have been investigated through transmission electron microscopy (TEM). Specimens were thinned through the use of a focused ion beam miller (FIB). TEM studies, including analysis of electron diffraction patterns from the agglomerated region of the specimen, revealed the presence of an aggregate of nano crystalline particles embedded in an amorphous phase, together with some larger alumina particles. These larger alumina particles appear at the base of pits in the alumina surface, whereas the finer material appears at the contact surface. The agglomerated debris was readily distinguished from the alumina substrate, which contained localised dislocation damage and microcracking. It is proposed that the wear process involves the removal of ‘large’ alumina particles from the surface by a combination of trans- and intergranular microcracking. These particles are then ground into very fine, nanometer-sized particles that react on the surface with moisture in the air to form an amorphous hydroxide film. These are then compacted to form a nanocrystalline structure within an amorphous matrix that may also be viewed as a grain boundary phase. 相似文献