Effect of Thickness on the Structure and Tribological Properties of MoSx Coating

MoSx coatings were prepared by bipolar-pulse DC unbalanced magnetron-sputtering system with the variation of coating thickness at different Ar pressures.The composition and surface morphology were determined by using energy dispersive X-ray and scanning electron microscopy;the structural characterization was analyzed by X-ray diffraction.The friction and wear properties were investigated by fretting tests in air with less than 10% and 50% relative humidity.At 0.40 Pa pressure,(002) basal plane orientation was formed throughout the coatings.At 0.88 Pa and 1.60 Pa pressures,(002) basal plane orientation was only noticed in the first stage of coating growth(around 0.20 μm in thickness), and then edge orientations with their basal planes perpendicular to the surface would be evolved in the coatings.Humidity has a minor influence on the coatings that have(002) basal plane orientation,whereas the tribological properties of MoSx coatings with edge orientations are greatly affected by humidity.The mechanisms of coating growth and friction and wear processes are discussed.     

固化对水性环氧粘结固体润滑涂层理化及摩擦学性能的影响

为了确定水性环氧粘结固体润滑涂层的最佳固化条件,采用MFT-R 4000型往复摩擦磨损试验仪评价了不同固化条件对其摩擦学性能的影响,用傅立叶变换红外光谱(FTIR)和示差扫描量热法(DSC)表征手段,确定了体系的最佳固化条件.结果表明:固化条件不同,涂层的摩擦学性能差异很大;水性粘结剂与水性固化剂的最佳质量比为2:1,最佳固化温度为75℃,最佳固化时间为2 h;以最佳条件制备的水性环氧粘结固体润滑涂层具有优异的理化性能和摩擦学性能,摩擦磨损寿命比传统的有机溶剂型粘结固体润滑涂层约长30%.本研究为制备高性能环保型粘结固体润滑涂层提供了可能.     

Si含量对VAlSiN涂层微结构、力学性能和摩擦磨损性能的影响

采用反应磁控溅射技术,在300℃下制备不同Si含量的VAlSiN涂层。研究Si含量的变化对VAlSiN涂层相结构、生长形貌、化学状态、力学性能和摩擦磨损性能的影响。结果表明:不含Si的VAlN涂层呈现(111)择优取向生长。随着Si含量的增加,VAlSiN涂层的(111)择优取向逐渐消失,最终转变为非晶结构。Si含量大于1.8%(原子分数,下同)的VAlSiN涂层是由nc-VAlN和a-Si_3N_4组成的多相复合涂层。与VAlN涂层相比,添加少量Si(0.8%)的VAlSiN涂层晶粒尺寸减小,致密度得到提高,对应的涂层硬度也得到显著增大,达到30.1GPa。继续增加Si的含量,VAlSiN涂层的柱状生长结构被打断,硬度逐渐下降,最后稳定在22GPa左右。VAlSiN涂层的摩擦因数随着Si含量的增加先降低后升高。当Si含量为0.8%时涂层的磨损率最低,达1.2×10~(-16)m~3·N~(-1)·m~(-1)。     

退火温度对DLC膜热稳定性及摩擦学性能的影响

采用非平衡磁控溅射技术分别在氮化硅陶瓷球和高速工具钢圆盘表面制备了类金刚石(DLC)膜。使用箱式电阻炉对DLC膜在大气环境中进行高温退火处理以研究环境温度对DLC膜摩擦学性能的影响;并分别采用激光拉曼光谱仪和球-盘式摩擦磨损试验机对退火处理前后DLC膜的结构和摩擦学性能进行了研究。采用金相显微镜观察了摩擦副磨损表面的形貌。研究发现,随着退火温度的升高,DLC膜中sp3杂化键向sp2杂化键的转化加快,当退火温度为600℃时,DLC膜发生严重的石墨化。而当退火温度为400℃时,DLC膜的摩擦系数及磨损率最小。拉曼测试表明400℃退火处理后DLC膜表层含有Si及SiO2,在摩擦过程中形成了含SiC的转移膜,使得DLC膜的摩擦系数明显降低,磨损减小。研究结果表明,退火处理对DLC膜的热稳定性和摩擦学性能有重要的影响。     

化学组成对聚苯胺类电流变体电流变效应的影响

制备了聚苯胺、聚甲基苯胺和溴化聚苯胺三种微粒,将其分别分散在氯化石蜡中形成电池变体以考察苯环取代基的性质对聚苯胺电流变效应的影响。结果表明,聚甲基苯胺电流变效应最强、溴化聚苯胺最弱。掺杂程度对聚苯胺和聚甲基苯胺电流变效应影响的研究表明,分别存在一适宜的掺杂程度使其电流变效应较好。少量的聚丙烯酸锂与聚苯胺的复合在不明显减弱其电流变效应的同时可降低其电流密度。     

超声处理对建筑用EVM表面离子镀DLC涂层组织和摩擦性的影响

通过超声方法处理聚氨基甲酸酯表面,选择脉冲碳离子源,结合阴极放电等离子方法在EVM表面完成DLC涂层的沉积过程,对超声处理过程中温度与时间参数引起的DLC涂层摩擦特性改变进行分析。实验测试研究结果表明:当超声处理的时间延长或者温度升高后,在试样表面形成了更深的条纹,能够显著增强EVM表面发生溶解的能力。DLC涂层在拉曼光谱测试过程中都形成低波数区间中的肩部结构,可以推断其光谱曲线都包含了D峰与G峰,在DLC膜内形成了跟高比例的石墨相。DLC涂层后的表面相对于EVM发生了摩擦系数稳定性下降,该结果表明DLC涂层可以使EVM获得更优耐磨性。当超声温度升高以及时间延长后,试样先发生摩擦系数的略微减小,之后发生逐渐升高。进行超声超声后,试样发生了磨损量的大幅降低,可以获得更致密的DLC涂层。     

Influence of the Composition of Electrolytes on the Properties of Plasma-Electrolytic Oxide Coatings on Light Alloys

Materials Science - We study the effect of various electrolytes on the functional characteristics of the coatings deposited by the method of plasma-electrolyte oxidation (PEO) on aluminum and...     

MoS2与石墨对聚四氟蜡粘接涂层摩擦学性能的影响

利用MHK-500型环块摩擦磨损试验机分别考察了M oS2与石墨对聚四氟蜡/聚氨酯复合涂层摩擦磨损性能的影响,采用扫描电子显微镜和光学显微镜观察分析了涂层磨损表面和偶件上转移膜的分布情况。研究表明,M oS2与石墨的加入使聚四氟蜡/聚氨酯复合涂层的耐磨性提高,但对摩擦系数影响较小,并且添加M oS2的聚四氟蜡粘接涂层的耐磨性要优于添加石墨的聚四氟蜡粘接涂层。同时,负荷和速度对添加M oS2与石墨的聚四氟蜡/聚氨酯复合涂层的摩擦磨损性能有很大影响。在高负荷中速条件下复合涂层具有较好的耐磨性能。     

新型固体润滑及油品添加剂-硫代钼酸盐的制备

研究了在水溶液中合成新型固体润滑兼油品添加剂一ＮｉＭｏＯ_２Ｓ_２及其原料（ＮＨ_４）_２ＭｏＯ_２Ｓ_２的条件,其最佳参数为ｐＨ＝４～５,温度为３０℃左右和ｐＨ＝７～９;温度为－５～０℃．还对产品的组成、结构及形貌进行了分析观察,并验证了ＮｉＭｏＯ_２Ｓ_２作为油品添加剂和固体润滑剂从２０～６００℃的减摩性能;证实硫代钼酸镍是一种宽温度范围的润滑剂．     

三种锡摩擦涂层的表面分析和摩擦学特性研究

针对钢一铜摩擦副类机械零件表面的磨损,研制了有减摩抗磨功能的锡类和锡锌复合类自修复添加剂.在摩擦试验中,润滑剂中的软金属微粒在机械作用下均能转移至铜表面上形成金属涂层.用俄歇能谱仪和扫描电镜分析了涂层表面的主要元素、涂层的形貌和厚度.测试结果表明,当润滑剂中的锡含量为20%时,涂层中锡的原子浓度接近80%,涂层厚度为10 μm;若在润滑剂中同时加入锡和锌两种微粒,经摩擦形成的锡锌涂层厚度为20 μm.锡脂和锡锌复合脂有较好的稳定性和防颗粒沉降性能.在MS-800摩擦磨损试验机上分别进行了纳米锡润滑剂、锡半流体脂和锡锌复合半流体脂的摩擦磨损特性,含锡量较高的涂层减摩抗磨性能较好,而加入锡锌两种添加剂形成的复合涂层具有更为优越的减摩特性.     

纳米金属Cu粉制备新方法及其对润滑油性能的影响

以无机铜盐为铜源,加入正己醇、span-80、tween-80,在N2气氛保护下,制得粒度可控、粒径在20-50nm的纳米铜,经SEM分析为球形,用四球摩擦试验机测试含有纳米铜润滑油的极压抗磨性能,结果表明,纳米铜粉的粒度越小,润滑油的极压抗磨性能越佳。     

新型固体润滑剂──氟化石墨的制备与性能的研究

通过电解熔盐KF·ZHF制取氟气,再将氟气与石墨在500℃时进行反应,从而制备了氟化石墨新材料．其密度值为2．53g／cm³、电阻率为3.1×10³Ω·cm,颜色为灰白色,在波数1219、1350cm^－1附近有F-C共价键红外光谱吸收峰．对氟化石墨、石墨、二硫化钼进行摩擦因数测试,结果表明：氟化石墨摩擦因数最小．还讨论了氟化石墨的一些特殊性能和工艺条件．     

纳米复合镀层的沉积机理及其摩擦特性的研究现状

综述了纳米复合镀层中纳米粒子的沉积机理和模型，以及纳米复合镀层的摩擦特性。     

Characterization of the Tribological Behavior of Different Tool Coatings and Dry Lubricant for High-Strength Aluminum Alloys at Elevated Temperatures

The use of high-strength aluminum components in automotive manufacturing offers the opportunity to reduce vehicle weight significantly and provide new lightweight potentials. In the past, the so-called hot forming and quench process (HFQ) successfully demonstrates the potential for the production of complex-shaped components made out of age-hardenable high-strength aluminum alloys. Currently, no method permits wear-free quench forming without the use of lubricants. To fulfill the increasing ecological and economic requirements, it is necessary to identify wear-reducing techniques to promote this forming technology in the future. This contribution investigates the interaction of lubricant and tool coatings on the tribological performance during quench forming of the high-strength aluminum alloy AA7075 at elevated temperatures. For this purpose, the tribological behavior is investigated using both, flat strip drawing tests and deep drawing operations. Subsequently, the component quality is compared and discussed. The results demonstrate that tool coatings are effective for the production of high-strength components in the HFQ process with minimal or even no lubrication and thus provide ecological as well as economic advantages.     

SiO_2对MoS_2/酚醛环氧树脂涂层原子氧辐照前后组成与性能的影响

为了有效降低低轨道原子氧辐照对黏结固体润滑涂层摩擦学性能的影响,满足航天器机械运动机构对空间润滑材料高可靠、长寿命的要求,在MoS_2/酚醛环氧树脂涂层中添加六甲基二硅胺烷修饰的SiO_2,制备了复合涂层,并用原子氧地面模拟装置进行辐照.分别采用X射线光电子能谱(XPS)、CSM摩擦磨损试验及扫描电子显微镜(SEM)分析了涂层原子氧辐照前后的化学组成、摩擦磨损性能及磨痕形貌.结果表明:添加SiO_2在一定程度上提高了MoS_2/酚醛环氧树脂涂层的抗原子氧剥蚀和摩擦磨损性能;添加2%SiO_2的涂层在原子氧辐照前后摩擦系数最低,耐磨性能最佳;当SiO_2添加量为1%时,涂层辐照前后的耐磨寿命最长.     

Influence of the Surface Chemical Treatment of D16T Alloy on the Protective Properties of Alkyd Coatings

Materials Science - The application of conversion coatings to D16T aluminum alloy significantly increases its corrosion resistance and weakens its subfilm corrosion under a lacquer coating. In the...     

Crack Formation in Gas-Thermal Coatings Depending on the Conditions of Their Laser Remelting

In the course of heating of Fe–Cr–B–Al electrometallized coatings on low-alloy steel by a scanning CO₂ laser beam, cracks, oriented mainly perpendicularly to the direction of scanning, can be initiated in the paths of the remelted coating. If the depth of the coating is small, the number of cracks and their width are greater. If the depth of remelting is comparable with the initial thickness of the coating, the number of cracks after its remelting decreases sharply.