磁控溅射MoS2薄膜的生长特性研究

利用非平衡磁控溅射技术制备出二硫化钼薄膜,并通过扫描电子显微镜和X射线衍射仪研究了工作气压和沉积时间对薄膜表面形貌和结构的影响及其演化规律。实验结果表明,在小于0.40 Pa的气压下,沉积MoS2薄膜的（002）面平行于基体表面,而在高于0.60Pa的高气压下,膜层的（002）面垂直于基体表面.在沉积初期,无论工作气压的高低,薄膜均按（002）基面的方式生长;在沉积后期,低气压下形成的薄膜仍按（002）基面方式生长,而在高气压下薄膜将转向以（002）基面与（100）或（110）棱面联合的方式生长。薄膜的表面形貌、微观结构,与薄膜的生长速率和沉积粒子的能量有关。     

射频磁控溅射法制备MoS2/SiC双层薄膜

采用射频磁控溅射法在室温、500℃的单晶硅和GCr15钢基体上制备了MoS2/SiC双层薄膜,并借助X射线衍射仪、扫描电子显微镜、摩擦磨损试验机以及划痕仪等研究了薄膜的结构、形貌、成分、摩擦学性能以及薄膜与基体的结合力。结果表明:当衬底温度为500℃时制备的MoS2/SiC双层薄膜表面致密平整,两层薄膜之间界面平直,膜厚约为0.8μm;该双层膜的摩擦因数低,耐磨性好;添加中间层可提高薄膜与基体的结合力。     

磁控溅射MoS2薄膜的结构和微观摩擦磨损特性

利用磁控溅射法制取了ＭｏＳ２薄膜,通过Ｘ光电子能谱、Ｘ射线衍射和ＡＦＭ／ＦＦＭ方法对薄膜的表面形貌、成分、化学价态、结构和微观摩擦磨损性能进行了研究。实验结果表明：ＭｏＳ２薄膜表面呈蠕虫状,微观结构为（１００）面平行于基面的非晶态,表面膜由ＭｏＳ２和少量的ＭｏＯ３组成。在微观摩擦磨损过程中,ＭｏＳ２薄膜的摩擦系数较大,且而磨性能高;微摩擦过程中没有磨合阶段,不存在摩擦机理的转变。     

MoS2/Al薄膜涂层磨损性能研究

采用磁控溅射法在304不锈钢表面制备双元复合涂层MoS₂/Al。采用EDS、扫描电子显微镜(SEM)、三维表面轮廓仪、摩擦磨损试验机等设备对涂层的摩擦学行为进行研究。结果表明，涂层的平均摩擦系数随着载荷的升高呈现下降趋势。载荷为2N时涂层的摩擦系数最高，达到0.34左右，载荷为20N时涂层的摩擦系数最低，约为0.21。对比单元MoS₂涂层可以发现，铝元素的加入提高了涂层的韧性与涂层的摩擦性能，MoS₂/Al复合涂层的破坏机制主要为裂纹的萌生和涂层的片状剥落。     

磁控溅射制备不锈钢薄膜研究

研究了磁控溅射镀膜工艺参数中溅射功率、溅射时间以及真空度等对不锈钢薄膜制备的影响，通过对获得的不锈钢薄膜层进行金相分析与其他性能测试发现：试验中溅射功率为100W、溅射时间为2h、真空度为0．08Pa、氩气压力为1．5MPa的条件下制得的薄膜性能最佳。     

载流下MoS2/Ag纳米复合薄膜摩擦学性能

MoS₂基纳米复合薄膜具有良好的摩擦学性能,但较差的导电性能限制了其在载流条件下作为润滑材料的应用。为提高MoS₂基纳米复合薄膜的导电性能,采用非平衡磁控溅射系统沉积2种不同Ag含量的MoS₂/Ag纳米复合薄膜,并在不同的电流条件下研究MoS₂/Ag纳米复合薄膜与GCr15钢球对摩时的摩擦学性能。结果表明：在载流下2种MoS₂/Ag纳米复合薄膜表现出相似的摩擦性能,而低掺杂MoS₂/Ag薄膜具有更佳的耐磨性能,这归因于低掺杂MoS₂/Ag薄膜具有较好的力学性能;无载流时,MoS₂/Ag纳米复合薄膜在摩擦过程中生成的氧化物颗粒增加了磨损、降低了润滑性,磨损机制主要为磨粒磨损;电流小于0.5 A时,电流促进了转移膜形成,使得摩擦因数降低,但磨损率增加,磨损机制主要为黏着磨损;当电流大于0.5 A时,由于电弧烧蚀加速了薄膜的磨损,磨损机制主要为磨粒磨损、黏着磨损和电弧腐蚀磨损。     

中频对靶反应磁控溅射Al2O3、TiO2、ZrO2功能薄膜的特性研究

利用中频对靶磁控溅射技术,分别制备出厚度低于5 μm、表面光滑的TiO2、ZrO2、Al2O3 3种功能薄膜.研究了不同工艺条件下薄膜的成膜速率和表面形貌,用四探针法测量了材料的薄膜电阻,并表征了膜层材料在大气压热等离子射流急速加热条件下的抗热冲击特性.     

射频磁控溅射制备HfMoNbZrNx薄膜的组织和性能

利用射频磁控溅射技术分别在单面抛光Si(001),Al₂O₃(0001)和硬质合金(WC-8 wt.%Co)基底表面沉积HfMoNbZrN_x薄膜,研究不同氮气流量R_N对HfMoNbZrN_x薄膜的组织和性能影响。结果表明,HfMoNbZr薄膜倾向于形成非晶态,随着R_N的增加,HfMoNbZrN高熵合金氮化薄膜转变为面心立方(FCC)结构并且沉积速率下降;当R_N=10%时,薄膜硬度和弹性模量最大,分别为21.8GPa±0.88GPa和293.5GPa±9.56GPa;所有薄膜均发生磨粒磨损,相较于多元合金薄膜,氮化物薄膜的磨损率下降了一个数量级,薄膜耐磨性显著提高。     

射频磁控溅射法制备二硫化钼薄膜

用射频磁控溅射法在GCr15钢表面制得了MoS2薄膜。通过扫描电镜、摩擦磨损以及划痕试验仪研究了工艺参数对薄膜形貌和性能的影响。结果表明:采用射频溅射法,在功率200W、工作气压3Pa、时间2h条件下制备的MoS2薄膜性能最佳;沉积过程中沉积原子从衬底表面获得足够的扩散能量时薄膜按层状模式生长,扩散能量不足时薄膜按层岛复合模式生长;MoS2薄膜摩擦因数低,具有优良的摩擦学特性。     

MoS2 single sheet lubrication by molybdenum dithiocarbamate

The mechanisms by which Modtc reduces friction in the centirange under boundary lubrication have been investigated using analytical tribometry. First, the SRV friction test was coupled with energy-filtering TEM on wear fragments and spatially-resolved XPS inside the wear scars. Second, we performed UHV friction tests on Modtc tribofilms previously created on a large area. The overall data demonstrate that the mechanisms of friction-reduction by Modtc is attributed to the effect of sliding between single layers of MoS₂ only, and not to intra-sliding in MoS₂ 3-D crystal. Highly-dispersed MoS₂ sheets are present in a carbon matrix in the tribofilm material. The growth of the 2-D MoS₂ single sheets is thought to be formed by degradation of the Modtc molecule by electron transfer mechanisms activated by the friction process. The lubrication of the uncoated, stationary counterface is attributed to successive transfer of individual sheets towards the friction surface. Practically, in these conditions only a few per cent of dispersed MoS₂ is sufficient to lubricate at the same level as pure MoS₂.     

钛合金表面磁控溅射制备羟基磷灰石/氧化钇稳定氧化锆复合涂层

采用磁控溅射法在Ti6Al4V基体上制备了HA／YSZ复合涂层。用X射线衍射仪、扫描电镜、原子力显微镜和划痕法对涂层进行了表征。结果表明：用磁控溅射法可在Ti6Al4V基体上成功制备HA／YSZ复合涂层,涂层主要含有HA、ZrO2和Y2O3物相,此外还有少量的TCP和CaO相;涂层表面呈多孔状,有利于类骨组织的长入,表面显微粗糙度约为140nm,涂层厚度约为4μm;划痕法测量涂层与基体的附着力约为80N。     

Friction and Wear Characteristics of C/Si Bi-layer Coatings Deposited on Silicon Substrate by DC Magnetron Sputtering

The tribological behavior of carbon/silicon bi-layer coatings deposited on a silicon substrate by DC magnetron sputtering was assessed and compared to that of amorphous carbon and silicon coatings. The motivation was to develop a wear resistant coating for silicon using thin layers of amorphous carbon and silicon. Wear tests were conducted by sliding a stainless steel ball against the coating specimens under applied normal loads in the range of 20?~?50?mN. Results showed that the wear rate of the bi-layer coating was strongly dependent on the ratio of thickness between the carbon and silicon layers. The wear rate of the bi-layer coating with 25?nm thick carbon and 102?nm thick silicon layers was about 48 and 20 times lower than that of the single-layer amorphous carbon and amorphous silicon coating, respectively. In addition, the steady-state friction coefficient of the bi-layer coating could be decreased to 0.09 by optimizing the thickness of the layer. Finally, a model for the wear reduction mechanism of the carbon/silicon bi-layer coating was proposed.     

Tribological performance of MoS2---B2O3 compacts

A recent investigation suggests that selected oxides perform well as additives in molybdenum disulphide (MoS₂) because of their ability to soften at asperity contacts with the result that the solid lubricant can attain and retain a preferred tribological orientation.This research determined the effectiveness of boric oxide (B₂O₃), when used as an additive in MoS₂, for substrate temperatures ranging from 21°C to 316°C. This range was used to allow the asperity contact temperature to vary below and above the softening point of B₂O₃. It was found that a moderate friction coefficient and high wear, which is attributed to the additive acting abrasively, occurred when the asperity contact temperature was well below the softening point of the oxide. When the asperity contact temperature neared the softening point of the oxide, the friction coefficient increased dramatically and wear volume was reduced. It is postulated that B₂O₃ acted adhesively at the interface resulting in a higher coefficient of friction, and wear decreased due to an attainment of a preferred orientation by the MoS₂. For asperity contact temperatures significantly above the softening point of B₂O₃, the friction coefficient returned to about the same value as for temperatures below the softening point. It is speculated that wear continued to increase moderately because of localized melting of the B₂O₃, permitting the MoS₂ to be removed from the interface. These observations support a hypothesis that an additive, such as boric oxide, can soften as the asperity contact temperature approaches the softening point temperature of the additive so that the overall tribological conditions may be improved resulting in reduced interfacial wear. Significant changes in temperature, load or sliding velocity would, of course, dramatically alter the wear characteristics observed at the interface.     

Effects of MoS2 concentration on friction

The effects of MoS₂ concentration on friction were investigated by using the ring compression test. An optimum concentration was found for friction. The optimum value is affected by specimen hardness and surface finish. A second optimum value also seems to exist for annealed (softer) 2011 aluminium alloy specimens.     

Morphological properties of sputtered MoS2 films

As the lubricating properties of MoS₂ are due to the sliding of lamellae, the crystallographic orientation and structural properties of these lamellae are important for the tribological behaviour. Thus an analysis of the growth morphology of sputtered MoS₂ films was carried out. It is shown that morphological properties can be influenced by the parameters of the deposition process; in particular, it is possible to prepare coatings in which the lamellae are oriented parallel to each other.     

磁控溅射法制备ZrW2O8薄膜及其性能

利用射频磁控溅射法在单晶硅片和石英基片上沉积了非晶态ZrW2O8薄膜,对不同温度下热处理的薄膜进行了XRD分析;用扫描电镜观察了薄膜的表面形貌,用阻抗分析仪和分光光度计分别研究了薄膜的介电性能和透光性能.结果表明:非晶态薄膜在740℃热处理3 min可以制得具有较好负热膨胀特性的ZrW2O8薄膜,其热膨胀系数为-2.54×10-5 /℃;介电常数和介电损耗均随着频率的增加而减小;在可见光范围内薄膜的透光率达75%.     

单层MoS2和WS2的太赫兹近场显微成像研究

采用太赫兹散射式扫描近场光学显微镜(THz s-SNOM)研究了化学气相沉积法制备的单层MoS₂和WS₂晶粒的太赫兹近场响应。在没有可见光激发时,未探测到可分辨的太赫兹近场响应,说明晶粒具有较低的掺杂载流子浓度。有可见光激发时,由于光生载流子的太赫兹近场响应,能够测得与晶粒轮廓完全吻合的太赫兹近场显微图。在相同的光激发条件下,MoS₂的太赫兹近场响应强于WS₂,反映了两者之间载流子浓度或迁移率的差异。研究结果表明,THz s-SNOM兼具超高的空间分辨率和对光生载流子的灵敏探测能力,对二维半导体材料和器件光电特性的微观机理研究具有独特的优势。