核-壳结构PS/CeO_2复合磨料的制备及其氧化物化学机械抛光性能

以无皂乳液聚合方法制备的聚苯乙烯(PS)微球为内核,硝酸铈为铈源,六亚甲基四胺为沉淀剂,采用液相工艺制备了PS/CeO2复合颗粒.利用XRD、TEM、SAED、FESEM、EDAX等手段,对所制备样品的物相结构、形貌、粒径大小和元素成分组成进行表征.将所制备的复合磨料用于硅晶片热氧化层的化学机械抛光,用AFM观察抛光表面的微观形貌,并测量表面粗糙度.结果表明,所制备的PS/CeO2复合颗粒具有核-壳结构,呈近似球形,粒径在250～300nm,PS内核表面被粒径在5～10nm的CeO2纳米颗粒均匀包覆,壳层的厚度为10～20nm.抛光后的硅热氧化层表面在5μm×5μm范围内粗糙度Ra值和RMS值分别为0.188nm和0.238nm,抛光速率达到461.1nm/min.     

Hydrothermal synthesis of star-like and dendritic PbS nanoparticles from new precursors

Lead sulfide (PbS) nanostructures with different morphologies and particle sizes were obtained via a simple hydrothermal reaction between lead (II) salicylate (Pb(Hsal)₂) and thiourea (tu). Reaction products were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet-visible (UV–vis) and Fourier transform infrared (FT-IR) spectroscopy. Morphology of the product, varying from star-like to dendritic, depends on the mole ratio of tu to (Pb(Hsal)₂), pH, and reaction time.     

Facile aqueous synthesis and thermal insulating properties of low-density glass/TiO2 core/shell composite hollow spheres

Anatase TiO2 shells assembled on hollow glass microspheres(HGM)with tunable morphologies were successfully prepared through a controllable chemical precipitation method with urea as the precipitator. Thus,glass/TiO2 core/shell composite hollow spheres with low particle density(0.40 g/cm3)were fabricated.The phase structures,morphologies,particle sizes,shell thicknesses,and chemical compositions of the composite microspheres were characterized by X-ray diffraction(XRD),scanning electron microscopy (SEM),and energy dispersive X-ray spectroscopy(EDS).The morphology of the TiO2 shell can be tailored by properly monitoring the reaction system component and parameters.The probable growth mechanism and fabrication process of the core/shell products involving the nucleation and oriented growth of TiO2 nanocrystals on hollow glass microspheres was proposed.A low infrared radiation study revealed that the radiation properties of the products are greatly influenced by the unique product shell structures. A thermal conductivity study showed that the TiO2/HGM possess low thermal conductivity that is similar to that of the pristine HGMs.This work provides an additional strategy to prepare low-density thermal insulating particles with tailored morphologies and properties.     

玻璃质无机非金属自润滑复合涂层的研制及其摩擦学性能的考察

作者用熔烧法制备了一种以玻璃相为骨架的自润滑复合涂层。试验结果表明,这种涂层在盐酸和氢氧化钠溶液中的摩擦磨损性能良好。引入过渡层可以改善涂层与底材间的物理匹配,加入氟化物、稀土氧化物(CeO_2)和三氧化二铬对涂层的显微结构和摩擦学性能具有重要影响。CeO_2添加量为3.0％的涂层在摩擦过程中产生的断裂颗粒可能会落入小孔而发生部分滚动,而且小孔中储存的溶液还可以承受部分载荷,因而在本试验条件下这种涂层的摩擦系数最低。     

烷氧基硼酸铈的合成及摩擦学性能研究

合成了油溶性的异辛氧基硼酸铈,并对其摩擦学性能进行了评价,利用Ｘ射线光电子能谱对磨损表面Ｂ元素的组成及化学状态进行了分析,结果表明,异辛氧基硼酸铈具有良好的承载能力和抗磨减摩性能,Ｘ射线光电子能谱分析结果表明,在摩擦表面膜中,Ｃｅ和Ｂ分别以ＣｅＯ２、Ｂ２Ｏ３和Ｆｅ２Ｂ的形式存在。     

Facile aqueous synthesis and thermal insulating properties of low-density glass/TiO2 core/shell composite hollow spheres

Anatase TiO₂ shells assembled on hollow glass microspheres (HGM) with tunable morphologies were successfully prepared through a controllable chemical precipitation method with urea as the precipitator. Thus, glass/TiO₂ core/shell composite hollow spheres with low particle density (0.40 g/cm³) were fabricated. The phase structures, morphologies, particle sizes, shell thicknesses, and chemical compositions of the composite microspheres were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). The morphology of the TiO₂ shell can be tailored by properly monitoring the reaction system component and parameters. The probable growth mechanism and fabrication process of the core/shell products involving the nucleation and oriented growth of TiO₂ nanocrystals on hollow glass microspheres was proposed. A low infrared radiation study revealed that the radiation properties of the products are greatly influenced by the unique product shell structures. A thermal conductivity study showed that the TiO₂/HGM possess low thermal conductivity that is similar to that of the pristine HGMs. This work provides an additional strategy to prepare low-density thermal insulating particles with tailored morphologies and properties.     

Vapour-diffusion assisted growth of oriented or-cobalt hydroxide thin films

Layered ,α-cobalt hydroxides Co(OH) 1.65Cl0.35.0.5H2O (1), Co(OH) 1.75(NO3)0.25.0.1H2O (2) with unique macro- and microscale morphologies have been synthesised by a low temperature, ammonia-controlled vapour-diffusion method. The materials have thin film morphologies and were characterized by X-ray powder diffraction (XRD) and field emission scanning electron microscopy (FESEM).     

二烷基磷酸锌作为润滑油添加剂的摩擦学行为研究

合成了二烷基磷酸锌(ZDP),采用四球摩擦试验机对其作为润滑油添加剂的摩擦磨损性能进行了研究,同时研究了ZDP与有机胺进行复配后的摩擦磨损性能.采用扫描电子显微镜(SEM)分析了磨损表面的微观形貌,采用X射线光电子能谱仪(XPS)分析了摩擦表面典型元素的化学状态.结果表明:ZDP作为润滑油添加剂与二烷基二硫代磷酸锌(ZDDP)相比,表现出低摩擦高磨损的性能;ZDP与有机胺复配之后表现出优异的摩擦磨损性能,其原因是由于复配之后在摩擦表面形成了复杂的含有N、P等元素的摩擦化学反应膜,同时提高了摩擦表面P元素的含量进而起到了降低摩擦磨损的作用.     

PFPE脂润滑2Cr13钢摩擦副的真空摩擦磨损行为研究

利用销-盘式摩擦磨损试验机对PFPE脂润滑2Cr13钢摩擦副进行了不同滑动时间的真空滑动摩擦磨损试验.采用扫描电子显微镜(SEM)、X射线光电子能谱仪(XPS)和傅里叶变换红外光谱(FTIR)分别对磨损表面的形貌、化学状态及润滑脂的结构和成分进行了系统分析.结果表明:随着滑动时间的增加,由微切削磨损、轻微腐蚀磨损向严重腐蚀磨损、轻度局部剥落继续向严重黏着磨损、严重局部剥落的严重复合磨损转变.在真空摩擦过程中PFPE润滑脂主要以物理退化为主,即润滑脂中基础油和增稠剂的相对比例发生变化.同时,PFPE润滑脂与2Cr13钢在摩擦过程中发生化学反应,生成具有催化作用的Fe F3.但由于所生成的Fe F3量较少,并未使PFPE润滑脂发生化学降解.     

氧化铈添加量对 M_(80)S_(20) 激光涂敷层的显微组织和摩擦学性能的影响

通过金相分析、扫描电子显微镜分析和透射电子显微镜分析，以及在无润滑条件下的摩擦磨损对比试验研究，考察了稀土氧化物ＣｅＯ２添加量对（Ｆｅ，Ｃｒ，Ｎｉ，Ｗ，Ｍｏ）８０（Ｂ，Ｓｉ，Ｃ）２０铁基非晶自熔合金粉末喷涂－激光重熔涂敷层的显微组织和摩擦磨损性能的影响．研究结果表明，在给定的试验条件下，稀土氧化物ＣｅＯ２的添加量（以质量分数计）为８％的改性效果比其添加量分别为４％和１２％的改性效果都好，可以明显改善激光涂敷层的显微组织，提高涂敷层的显微硬度，而且此时涂敷层的摩擦学性能最好．     

镍掺杂白云母复合粉体的制备及其作为润滑脂添加剂的摩擦学性能

采用液相还原法制备了纳米镍掺杂白云母微粉(Muscovite,简记为Mu)的复合粉体Mu/Ni,表征了复合粉体的微观形貌、晶体结构和元素组成.利用环-块摩擦磨损试验机考察并比较了Mu/Ni和Mu作为锂基润滑脂添加剂的摩擦学性能,对磨损表面的粗糙度、二维和三维形貌以及元素组成进行了分析,探讨了Mu/Ni复合粉体的减摩抗磨机理.结果表明:复合粉体中纳米镍粒子均匀负载在白云母微粉表面,Mu/Ni和Mu作为添加剂均能有效提高锂基润滑脂的摩擦学性能,且Mu/Ni相比于Mu表现出更好的减摩抗磨性能,摩擦系数较锂基润滑脂降低了67.9%.Mu/Ni优良的摩擦学性能与白云母的层状结构及磨损表面生成的含有O、Fe、Si、Al和Ni等元素的润滑膜有关.     

纯钛与Ti6Al7Nb合金氮离子注入层在小牛血清溶液中的扭动微动磨损试验研究

文中主要研究了纯钛、Ti6A17Nb基体以及经过氮离子注入后的改性层的扭动微动磨损行为.氮离子注入采用高能离子注入机及增强沉积系统,加速电压为50 kV,注入剂量分别为1×l017、5×1017和9×1017cm-2.采用球/平面接触模式,对纯钛和Ti6Al7Nb合金/(Zr2O球(直径为25.2 mm),接触副在小牛血清介质条件下进行了纯钛和Ti6Al7Nb合金及其改性层的了扭动微动磨损试验.借助X衍射仪(XRD)、拉曼光谱(Raman)、三维形貌仪(3D)和扫描电镜(SEM)分析了两种材料及其改性层的化学成分、微动磨损磨痕形貌和微观组织结构,探讨了纯钛和Ti6Al7Nb合金基材和改性层的扭动微动运行行为和损伤机制.研究结果表明:用氮离子注入方法处理钛及其合金,生成的氮化物层能够改善材料表面的综合性能,提高其扭动微动磨损的耐磨性.纯钛和Ti6Al7Nb基体的磨损现象为氧化和剥落,其离子注入层的磨损现象为犁沟.     

两种含氟空间润滑油的真空摩擦磨损行为研究

利用真空四球摩擦试验机系统考察了全氟聚醚（Z25）和甲基氟氯苯基硅油（FCPSO）两种空间润滑油在空气、真空和高纯氮气气氛中的摩擦磨损性能,采用扫描电子显微镜（SEM）和X射线光电子能谱仪（XPS）分别分析了磨损表面的微观形貌及典型元素的化学状态。结果表明：Z25在3种气氛中均表现出低摩擦高磨损的特性,且真空中摩擦系数最低,这主要是由于Z25对摩擦副具有润滑和腐蚀的双重作用;FCPSO在3种气氛中均表现出高摩擦低磨损的特性,且真空中磨斑直径最小,这主要是由于FCPSO在摩擦副表面形成了FeCl2边界保护膜.     

双层自组装分子/离子液体复合润滑薄膜的制备及其摩擦学性能研究

利用自组装和喷覆技术,在单晶硅(Si)表面制备了N-3-(三甲氧基硅烷基)丙基乙二胺(DA)-月桂酰氯(LA)-1-十二烷基-3-甲基咪唑六氟磷酸盐离子液体(ILs)双层自组装分子/离子液体复合润滑薄膜(DA-LA-ILs).采用接触角测量仪、傅里叶变换红外光谱仪(FTIR)和原子力显微镜(AFM)对复合润滑薄膜进行了润湿性能、分子组分、微观形貌和微尺度黏附行为的研究;利用球-盘摩擦磨损试验机研究了该薄膜的摩擦学性能.结果表明:经DA-LA-ILs复合润滑薄膜改性后,有效改善了Si表面的微观黏着性能;同时,相较于DA-LA双层自组装分子膜改性的Si表面和直接由ILs修饰的Si表面,该复合润滑薄膜具有良好的宏观减摩抗磨性能.研究为DA-LA-ILs复合润滑薄膜应用于微机电系统,降低微接触表面的黏着并提高耐磨性能提供了理论依据和试验基础.     

Yttria-stabilized-zirconia hollow spheres prepared by atmospheric plasma spray

Yttria-stabilized-zirconia （YSZ） hollow spheres are widely utilized for their novel physical and chemical properties. However, developing a simple and low-cost method for preparing such hollow spheres still remains a great challenge. In this paper, an atmospheric plasma spray （APS） method is introduced, and the formation mechanism of hollow 7YSZ （ZrO2-7wt%Y2O3） spheres is presented. The hollow sphere morphology was observed by scanning electron microscopy （SEM） when agglomerated and sintered 7YSZ powders were used. Additionally, additive composition changes, phase transformations, and the thermal behavior of 7YSZ powders were analyzed by energy dispersive spectroscopy （EDS）, X-ray diffractometry （XRD）, thermogravimetric analysis （TG） and differential scanning calorimeter analysis （DSC）. Furthermore, the phase transformations of agglomerated and sintered 7YSZ powders, 7YSZ hollow spheres that annealed at various temperatures for different times are analyzed.     

单晶硅表面稀土复合纳米膜的制备与摩擦特性

利用分子自组装技术,在单晶硅表面制备了稀土复合纳米自组装膜.运用原子力显微镜(AFM)观察了薄膜的表面形貌,使用X射线光电子能谱仪(XPS)分析了薄膜表面典型元素的化学状态,并运用静-动摩擦系数测定仪评价了薄膜的摩擦磨损性能.研究结果表明:通过硅烷偶联剂3-巯丙基三甲氧基硅烷(MPTS)的磺酸基化学吸附功能,稀土元素可以成功组装到氧化后的硅烷化表面.当组装稀土复合膜后,基片表面的摩擦系数由无膜时的0.8降到了0.08,表明复合膜可以降低基片的摩擦系数,并且在较低载荷下具有较好的耐磨性能.     

SURFACE METALLIZATION OF CENOSPHERES AND PRECIPITATORS BY ELECTROLESS PLATING

This paper reports the use of a colloidal Pd^0 catalysis system to metallize the surface of precipitators separated from coal fly-ash, and metals such as Cu, Ni etc. are deposited on the precipitators surface. Alternatively, according to the characteristic surface of cenospheres, an Ag coating catalysis system is adopted to first deposit Ag on the cenospheres surface, followed, if necessary, by the deposition of other metals such as Cu, Ni, etc. on the Ag coating to produce monolayer and multilayer metal-coated cenospheres. The surface characteristics and the morphologies of the metal coatings are examined in detail with scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) techniques. It can be shown that the quality of metal coatings derived from the Aa coatina catalysis system, is better than that of the colloidal Pd^0 catalysis system.     

壳层形态对核/壳结构PS/SiO_2复合磨料抛光性能的影响

以聚苯乙烯(PS)微球为内核,通过控制正硅酸乙酯的水解过程制备具有不同壳层形态的核/壳结构PS/SiO2复合磨料,应用于二氧化硅介质层的化学机械抛光,借助AFM测量抛光表面的形貌、轮廓曲线及粗糙度.SEM和TEM结果显示:碱性水解条件下,复合磨料的壳层由SiO2纳米颗粒组成(非连续壳层);酸性条件下,复合磨料的壳层则呈无定型网状(连续壳层).抛光对比试验结果表明:复合磨料的PS弹性内核有利于降低表面粗糙度并减少机械损伤,SiO2壳层则有利于提高材料去除率,复合磨料的核/壳协同效应对于提高抛光质量具有主要影响.相对于非连续壳层复合磨料,具有连续壳层的PS/SiO2复合磨料能够得到更低的抛光表面粗糙度值(RMS=0.136 nm),且在抛光过程中表现出了更好的结构稳定性.然而,PS/SiO2复合磨料的壳层形态对抛光速率的影响则不明显.     

高温润滑脂中WS_2亚微米粒子的摩擦学性能研究

以新型润滑材料WS2亚微米粒子作为高温润滑脂添加剂,对其在高温润滑脂中于不同温度下所起的抗磨、减摩、抗极压等摩擦学性能进行了研究,并用电子探针显微镜和俄歇电子能谱仪分析了钢球磨斑表面形貌与表面典型元素的面分布和深度分布.结果表明:在不同温度尤其高温下,WS2亚微米粒子能显著提高润滑脂的摩擦学性能;在摩擦过程中,WS2亚微米粒子在摩擦副表面形成WS2吸附膜和含Fe、S的化学反应膜来有效减少摩擦磨损,增强润滑脂的抗磨、减摩和极压性能,从而更好地保护摩擦表面.     

纳米碳酸钙作为润滑脂添加剂的摩擦学性能及流变行为研究

使用碳化法制备出三种具有不同粒径的纳米碳酸钙颗粒,利用透射电镜(TEM)和X射线衍射仪(XRD)对其形貌及结构组成进行表征.通过UMT-2摩擦学试验机及RS6000流变仪分别考察了纳米颗粒作为润滑脂添加剂的摩擦学性能及流变学行为,并通过X射线多功能电子能谱仪(XPS)对磨斑表面进行分析.结果表明:所制备的三种纳米颗粒均为方解石结构,可以显著提高基础脂的减摩抗磨性能;添加剂浓度及添加剂尺寸均会影响润滑脂最终的摩擦学性能;在最佳添加浓度和尺寸条件下,能够同时获得最佳的抗磨减摩性能;过高的添加剂浓度会影响润滑脂的结构稳定性,进而影响其摩擦学性能;三种纳米添加剂在磨斑表面形成以碳酸钙为主要成分的润滑膜,纳米颗粒物理性质的差异可能导致其摩擦学性能的差异.