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考察了纳米SiO2对聚丙烯酸酯复合涂层在水润滑下摩擦磨损性能的影响。利用FTIR分析纳米SiO2与聚丙烯酸酯的界面结合;利用SEM观察复合涂层磨损表面,并结合FTIR和摩擦磨损实验分析其磨损机理。结果表明:水润滑时,聚丙烯酸酯在摩擦过程中会发生摩擦化学反应,引起涂层摩擦腐蚀磨损;而纳米SiO2能与聚丙烯酸酯以化学键的形式结合,它的加入有助于摩擦界面在水介质中形成具有较好减摩作用的表面膜和水分子膜,提高聚丙烯酸酯复合涂层的耐磨性。在水润滑下,当纳米SiO2的含量较低时,涂层表面的磨损形式为摩擦腐蚀磨损和磨粒磨损;当纳米SiO2的含量达到5wt% 时,涂层表面形成完整的表面膜和水分子膜,此时涂层具有良好的摩擦学性能。 相似文献
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以醋酸铜为母体,维生素C(Vc)为还原剂,吐温-80为修饰剂,用原位合成一步法在基础油液体石蜡中成功制备了粒径分布为2.3—9.5nm、平均粒径为4.3nm的纳米铜胶。以制备的纳米铜胶的液体石蜡为润滑油添加剂,将其分散于关孚1号5w-30全合成机油中,制得分散稳定性、兼容性优良的纳米润滑油,在UMT-II摩擦磨损实验机、四球摩擦磨损实验机上分别考察添加纳米铜胶的润滑油的摩擦学性能,利用扫描电镜(SEM)和能谱散射光谱(EDS)分析磨损表面形貌,结果表明,添加的纳米铜胶在摩擦表面的划痕和犁沟处沉积并铺展成膜,相比关孚1号5w-30全合成机油,较大程度地降低了摩擦副的摩擦因数,显著改善了润滑油的润滑性能,表现出优异的抗磨减磨性能、极压性能和极限工作能力等摩擦学性能。 相似文献
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层状Cr2AlC纳米晶的合成及其摩擦学行为 总被引:1,自引:0,他引:1
通过液相磁力搅拌混合原料粉末2Cr/1.2Al/1C,在1400℃无压烧结合成了Cr2AlC。X射线衍射结果表明,Cr2AlC具有良好的结晶性,扫描电镜照片显示合成的Cr2AlC为层状结构,厚度大约在50~100 nm。将其以不同质量分数分散到基础油100SN中,利用摩擦磨损试验机初步研究了滑行速度,载荷等对其摩擦学性能的影响,结果表明,Cr2AlC添加量较低时,分散性较好,能显著降低基础油的摩擦系数和摩擦磨损,高载荷会加剧磨损,实验条件下,Cr2AlC添加量为0.6%和1%的润滑油在10N载荷时,摩擦过程中在表面形成具有减摩抗磨作用的润滑膜,表现出较好的摩擦学性能。 相似文献
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采用溶胶一凝胶法制备了硬脂酸表面修饰纳米TiO2颗粒,使用冷冻蚀刻电镜(FEEM)对其进行了形貌表征,用MM-WlA型四球试验机评价了其摩擦学性能,并考察了与硫化烯烃的复配规律。结果表明,所制备的纳米TiO2颗粒大小均匀,没有明显的团聚现象,在基础油中能起到极压抗磨作用,具有良好的极压性能,有利于提高油品的承载能力。另外,所制备的纳米TiO2添加剂与硫化烯烃有很好的复配效应,可以大幅度提高基础油的抗烧结负荷,这对于提高齿轮油的承载能力,具有非常重要的应用价值。 相似文献
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将Mg(OH)2/Fe(OH)3混合体超声活化4h,固相合成制备了尖晶石型MgFe2O4粉末。通过TG-DTA、XRD和TEM测试,分析固相反应的机理、材料的化学成分和微观结构。用振动样品磁强计(VSM)、矢量网络分析仪研究材料的电磁性能。结果表明,700℃下制备的MgFe2O4颗粒为纳米级单晶结构,纯度高,结晶性好,粒径分布为20~45nm;Mg-Fe2O4的比饱和磁化强度Ms=21.015A.m2/kg,剩磁Mr=2.5798A.m2/kg,矫顽力Hc=9.017×10-3T,MgFe2O4对7~18GHz范围内的电磁波表现为介电损耗。 相似文献
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采用化学方法制备了SiO2/SnO2复合纳米添加剂,在四球摩擦磨损试验机上考察了其在菜籽基础油中的抗磨减摩性能。用扫描电子显微镜观察分析钢球磨斑表面的形貌,同时通过对钢球磨痕表面进行X-射线光电子能谱分析,探讨了SiO2/SnO2复合纳米添加剂的抗磨减摩机理。结果表明:SiO2/SnO2复合纳米添加剂具有优良的减摩抗磨性能,其润滑作用机理是因为SiO2/SnO2复合纳米添加剂在摩擦表面沉积并在接触区的高温高压作用下熔融铺展,形成低剪切强度的表面膜,由于这层膜的剪切强度比较低,可以减少摩擦界面的粘着磨损,故表现出良好的减摩抗磨性能。 相似文献
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纳米SiO2对聚醚砜酮复合材料摩擦学性能的影响 总被引:10,自引:0,他引:10
在MM-2000型摩擦磨损试验机上考察了不同载荷和速度下纳米SiO2含量对聚醚砜酮(PPESK)复合材料摩擦磨损性能的影响,并利用扫描电子显微镜(SEM)观察分析PPESK及纳米SiO2/PPESK复合材料磨损表面形貌及磨损机理,结果表明:纳米SiO2不但可以提高PPESK的耐磨性,而且还有较好的减摩作用,在本研究的试验条件下,当纳米SiO2的质量分数为25%时,填充PPESK复合材料具有最佳摩擦学性能。随着载荷的增大,填充PPESK的摩擦系数降低,填料含量在20%质量分数以下时随载荷增大其耐磨性提高较明显,而填料含量超过20%质量分数时载荷对复合材料耐磨性的影响不大。 相似文献
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FeCrBSi/FeS层真空辐照环境下的组织结构与摩擦学性能研究 总被引:2,自引:0,他引:2
采用超音速等离子喷涂+低温离子渗硫技术在45#钢基体上制备了FeCrBSi/FeS复合涂层,考察了该复合涂层在大气、真空、原子氧辐照、紫外线辐照后的表面形貌、磨痕形貌及元素组成。利用真空摩擦磨损试验机分别完成了干摩擦条件下四种环境中的摩擦磨损性能测试。结果表明:复合FeCrBSi/FeS层经过原子氧及紫外线辐照后,有部分元素被氧化及化合物分解的现象,但并没有发生明显的材料性能改变以及润滑涂层的破坏。与45#钢相比,四种环境下该复合涂层均具有良好的润滑减摩效果。此研究表明,复合FeCrBSi/FeS层具有一定的抗原子氧和紫外线辐照的能力。 相似文献
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Yang Gao Yi‐Lun Hong Li‐Chang Yin Zhangting Wu Zhiqing Yang Mao‐Lin Chen Zhibo Liu Teng Ma Dong‐Ming Sun Zhenhua Ni Xiu‐Liang Ma Hui‐Ming Cheng Wencai Ren 《Advanced materials (Deerfield Beach, Fla.)》2017,29(29)
The ultrafast growth of high‐quality uniform monolayer WSe2 is reported with a growth rate of ≈26 µm s?1 by chemical vapor deposition on reusable Au substrate, which is ≈2–3 orders of magnitude faster than those of most 2D transition metal dichalcogenides grown on nonmetal substrates. Such ultrafast growth allows for the fabrication of millimeter‐size single‐crystal WSe2 domains in ≈30 s and large‐area continuous films in ≈60 s. Importantly, the ultrafast grown WSe2 shows excellent crystal quality and extraordinary electrical performance comparable to those of the mechanically exfoliated samples, with a high mobility up to ≈143 cm2 V?1 s?1 and ON/OFF ratio up to 9 × 106 at room temperature. Density functional theory calculations reveal that the ultrafast growth of WSe2 is due to the small energy barriers and exothermic characteristic for the diffusion and attachment of W and Se on the edges of WSe2 on Au substrate. 相似文献
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Chunsen Liu Xiao Yan Enze Zhang Xiongfei Song Qingqing Sun Shijin Ding Wenzhong Bao Faxian Xiu Peng Zhou David Wei Zhang 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(18)
The abundant electronic and optical properties of 2D materials that are just one‐atom thick pave the way for many novel electronic applications. One important application is to explore the band‐to‐band tunneling in the heterojunction built by different 2D materials. Here, a gate‐controlled WSe2 transistor is constructed by using different work function metals to form the drain (Pt) and source (Cr) electrodes. The device can be gate‐modulated to exhibit three modes of operation, i.e., the tunneling mode with remarkable negative differential resistance, the transition mode with a second electron tunneling phenomenon for backward bias, and finally the conventional diode mode with rectifying characteristics. In contrast to the heterojunctions built by different 2D materials, these devices show significantly enhanced tunneling current by two orders of magnitude, which may largely benefit from the clean interfaces. These results pave the way toward design of novel electronic devices using the modulation of metal work functions. 相似文献
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Tunneling Diode Based on WSe2/SnS2 Heterostructure Incorporating High Detectivity and Responsivity
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Xing Zhou Xiaozong Hu Shasha Zhou Hongyue Song Qi Zhang Lejing Pi Liang Li Huiqiao Li Jingtao Lü Tianyou Zhai 《Advanced materials (Deerfield Beach, Fla.)》2018,30(7)
van der Waals (vdW) heterostructures based on atomically thin 2D materials have led to a new era in next‐generation optoelectronics due to their tailored energy band alignments and ultrathin morphological features, especially in photodetectors. However, these photodetectors often show an inevitable compromise between photodetectivity and photoresponsivity with one high and the other low. Herein, a highly sensitive WSe2/SnS2 photodiode is constructed on BN thin film by exfoliating each material and manually stacking them. The WSe2/SnS2 vdW heterostructure shows ultralow dark currents resulting from the depletion region at the junction and high direct tunneling current when illuminated, which is confirmed by the energy band structures and electrical characteristics fitted with direct tunneling. Thus, the distinctive WSe2/SnS2 vdW heterostructure exhibits both ultrahigh photodetectivity of 1.29 × 1013 Jones (Iph/Idark ratio of ≈106) and photoresponsivity of 244 A W?1 at a reverse bias under the illumination of 550 nm light (3.77 mW cm?2). 相似文献
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研究了NbSe2的添加对铜-石墨固体自润滑材料的影响,采用粉末冶金法将制备的不同质量百分比含量的纤维状或片层状的纳米NbSe2材料与铜粉、石墨粉混合均匀,冷压制成小圆盘.采用光学显微镜,SEM(JSM-7001F扫描电子显微镜)等手段表征表面形貌.并在超低温摩擦磨损机和UMT-2摩擦试验仪上测试其摩擦性能.实验结果表明... 相似文献
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Hai Li Gang Lu Yanlong Wang Zongyou Yin Chunxiao Cong Qiyuan He Lu Wang Feng Ding Ting Yu Hua Zhang 《Small (Weinheim an der Bergstrasse, Germany)》2013,9(11):1974-1981
Single‐ and few‐layer transition‐metal dichalcogenide nanosheets, such as WSe2, TaS2, and TaSe2, are prepared by mechanical exfoliation. A Raman microscope is employed to characterize the single‐layer (1L) to quinary‐layer (5L) WSe2 nanosheets and WSe2 single crystals with a laser excitation power ranging from 20 μW to 5.1 mW. Typical first‐order together with some second‐order and combinational Raman modes are observed. A new peak at around 308 cm?1 is observed in WSe2 except for the 1L WSe2, which might arise from interlayer interactions. Red shifting of the A1g mode and the Raman peak around 308 cm?1 is observed from 1L to 5L WSe2. Interestingly, hexagonal‐ and monoclinic‐structured WO3 thin films are obtained during the local oxidation of thinner (1L–3L) and thicker (4L and 5L) WSe2 nanosheets, while laser‐burned holes are found during the local oxidation of the WSe2 single crystal. In addition, the characterization of TaS2 and TaSe2 thin layers is also conducted. 相似文献
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Thin films of tungsten disulfide (WS2) were deposited on 3Cr13 martensitic stain less steel substrate by radio-frequency (RF) sputtering. The as-deposited films were annealed at 473, 673 and 873 K respectively for 2 h in 5 × 10− 4 Pa vacuum. Composition of the films was inspected by energy dispersive spectroscopy. Surface morphology and structure properties were studied by scanning electron microscopy and X-ray diffraction techniques. Tribological behavior was also examined using tribometer. At 473 K, the films exhibited low crystallization structure and no significant improvement in the tribological performance. At 673 K, the tribological performance was improved and a transition from non-crystalline to hexagonal structure took in place. When the annealing temperature rose up to 873 K, the films cracked and fell off from the substrate. The results suggested that with suitable technical parameters vacuum annealing could promote crystallization and improve tribological performance of RF sputtering WS2 films. 相似文献
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Jinxin Liu Mengqi Zeng Lingxiang Wang Yongting Chen Zhuo Xing Tao Zhang Zheng Liu Junlai Zuo Fan Nan Rafael G. Mendes Shengli Chen Feng Ren Ququan Wang Mark H. Rümmeli Lei Fu 《Small (Weinheim an der Bergstrasse, Germany)》2016,12(41):5741-5749
The controllable synthesis of uniform tungsten diselenide (WSe2) is crucial for its emerging applications due to the high sensitivity of its extraordinary physicochemical properties to its layer numbers. However, undesirable multilayer regions inevitably form during the fabrication of WSe2 via the traditional chemical vapor deposition process resulted from the lack of significantly energetically favorable competition between layer accumulation and size expansion. This work innovatively introduces Cu to occupy the hexagonal site positioned at the center of the six membered ring of the WSe2 surface, thus filtrates the undesired reaction path through precisely thermodynamical control and achieves self‐limited growth WSe2 crystals. The as‐obtained WSe2 crystals are characterized as strictly single‐layer over the entire wafer. Furthermore, the strictly self‐limited growth behavior can achieve the “win–win” cooperation with the synthesis efficiency. The fastest growth (≈15 times of the growth rate in the previous work) of strictly monolayer WSe2 crystals thus far is realized due to the high‐efficiency simultaneous selenization process. The as‐proposed ultrafast Cu‐assisted self‐limited growth method opens a new avenue to fabricate strictly monolayer transition metal dichalcogenides crystals and further promotes their practical applications in the future industrial applications. 相似文献
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为探索界面工程对二维材料范德华异质结构中载流子复合率的影响, 本工作基于界面键弛豫理论和费米黄金定则, 建立了范德华异质结俄歇和层间复合率与各结构组元尺寸之间的理论模型。结果表明, MoS2/WSe2异质结的俄歇复合寿命随着组元尺寸的增大而增加, 且异质结的俄歇复合率远小于相应的单组元体系。在MoS2/WSe2双层异质结中引入薄h-BN插层后, 体系的层间复合率和俄歇复合率随h-BN厚度的增加而分别呈现减小和增大的趋势; 在组元处于单层MoS2和WSe2情况下, 当界面插层h-BN厚度达到9.1 nm时, 俄歇复合率将趋于5.3 ns -1。该研究结果为二维过渡金属硫族化合物基异质结光电器件的优化设计提供了一种理论依据。 相似文献