不同钢种离子渗硫层的抗擦伤性能研究

为改善高速钢，模具钢和45钢的抗擦伤性能，采用低温离子渗硫技术在这三种材料表面生成了FeS固体润滑渗硫层，在QP-100球盘式摩擦磨损试验机上对比研究了这三种材料渗硫层在油润滑条件下的抗擦伤及摩擦学性能。利用SEM与XRD观察分析了渗硫层截面，擦伤面形貌及表面相结构，利用AES及XPS分析了擦伤表面元素沿深度的分布及边界润滑膜化合物的价态，研究表明，渗硫后三种材料的抗擦伤及摩擦学性能都有明显改善，其中渗硫高速钢的抗擦伤性最好。其后依次为渗硫模具钢，渗硫45钢，分析认为，不同钢种渗硫层抗擦伤性能的差异主要由基体硬度，组织结构及耐蚀性三方面决定。     

车轴钢表面渗氮/渗硫复合层的扭动微动磨损研究

通过对LZ50车轴钢表面进行渗氮/渗硫复合处理,在其表面形成渗氮/渗硫复合层。在对复合层进行表征的基础上,研究了复合层和基体在干态不同角位移幅值下的扭动微动磨损行为。结果表明:渗氮/渗硫复合层由ε-Fe2-3N,γ′-Fe4N,FeS和FeS2相组成;复合层改变了LZ50钢的扭动微动运行区域,使得混合区减小,滑移区向小角位移方向移动;由于高硬度的渗氮层支撑和渗硫层润滑作用,复合层的摩擦扭矩在部分滑移区和滑移区低于LZ50钢;与LZ50钢相比,复合层的磨损程度明显降低,在部分滑移区损伤轻微,在混合区和滑移区,复合层的损伤主要表现为剥层,磨粒磨损和氧化磨损。     

低温离子渗硫催渗技术研究现状及展望

低温离子渗硫技术可制备摩擦学性能优良的固体润滑剂,目前制备的渗硫层覆盖不均匀,保存运输过程中易损坏,服役寿命较短。综述了低温离子渗硫技术的各种催渗工艺与方法以及各自的特点与适用范围,并指出了该技术未来的发展趋势。     

偏压对活性屏离子渗氮工艺的影响

通过对40C钢进行活性屏离子渗氮处理,研究了在活性屏离子渗氮工艺过程中工件所加的偏压对渗氮层的影响.试验结果表明,在不加偏压或偏压较低的情况下,对距离活性屏较近的工件,其表面有一定厚度的渗氮层形成,硬度提高;而距离活性屏较远的工件,其表面几乎没有渗氮层的形成,但当增大偏压至400～450 V时,工件表面产生弱的辉光放电...     

镍基激光熔覆层纳米化、低温离子渗硫后的摩擦学性能

为保证低温离子渗硫层的厚度与均匀性,用超声滚压技术将45钢表面激光熔覆镍基层纳米化,再低温离子渗硫。利用XPS和XRD技术分析了硫化物层的物相组成;在UMT-3型球盘式可控环境摩擦磨损试验机上研究了干摩擦和46号机械油润滑下熔覆层纳米化与否渗硫层的摩擦学性能,利用SOHIO型三维白光干涉表面形貌仪测量了磨痕三维形貌。结果表明:熔覆层纳米化后的渗硫层致密、均匀,表面S元素的质量分数由5%增加到13%左右,渗硫层中的硫化物以Fe S为主,Fe S2含量明显减少;干摩擦条件下熔覆层纳米化后渗硫层的摩擦系数由未纳米化的0.60降低到0.45,磨痕形貌窄而浅,摩擦学性能明显优于未纳米化的渗硫层。     

FeCrBSi/FeS层真空辐照环境下的组织结构与摩擦学性能研究

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。     

低温离子渗硫技术的发展历程和研究应用现状

在综述渗硫技术的发展历程和分类的基础上,重点介绍了低温离子渗硫的工艺流程和离子渗硫层的形成机理,总结归纳了低温离子渗硫工艺的技术、经济优势和社会环保效益,概述了低温离子渗硫技术在各类典型的滚动件、滑动件和重载零件上的应用现状以及低温离子渗硫工业化生产设备的研究情况。指出低温离子渗硫技术未来将继续向绿色环保、简单高效等方向发展。     

低温离子渗硫层的结构和减摩性能

采用低温离子渗硫技术在４５和ＧＣｒ１５钢表面形成一定厚度的渗硫层。采用金相,ＳＥＭ＋ＥＤＸ,ＸＲＤ等方法分析了渗层结构。采用ＳＲＶ往复式磨损试验机。在液体石蜡润滑条件下对渗层的摩擦学性能进行了研究。     

35CrMo钢硫氮共渗层的摩擦学性能

目前,低温离子渗硫技术在石油钻杆丝扣上的应用还没有先例.应用离子渗氮与离子渗硫技术,在35CrMo钢表面制备了硫氮共渗复合层.采用自制的球-盘磨损试验机,在含铜润滑脂润滑条件下,对比研究了离子渗氮层与硫氮共渗层的摩擦磨损性能;采用白光干涉仪和扫描电子显微镜观察了表面改性层和磨损表面的形貌,利用纳米压痕仪测量了渗层的硬度和弹性模量,用X射线光电子能谱研究了磨损表面边界润滑膜的元素成分及其含量随深度的变化.结果表明,35CrMo钢经硫氮共渗处理后,表面比较粗糙,硬度较低,符合理想的摩擦表面要求;硫氮共渗层有了渗氮层的支撑,其减摩耐磨性能在低速低载下优于渗氮层,满足钻杆接头的使用性能要求.     

离子硫化层与热喷涂硫化层的摩擦学性能比较

分别采用低温离子渗硫和等离子喷涂的方法在45^#钢表面制备了硫化层。在摩擦磨损试验机上对比研究了这两种硫化层在油润滑条件下的摩擦学性能。利用XRD分析了硫化层的相结构，用SEM观察了硫化层的表面及磨面形貌并进行了能谱分析。结果表明，各硫化层的摩擦学性能明显优于原始基体表面，其中离子硫化层的减摩性和耐磨性更好，耐热喷涂硫化层的抗擦伤性更佳。造成这种差别的主要原因在于两种硫化层的成膜机理不同。     

单屏式多点气流温度传感器现场校准工况参数影响分析

采用数值仿真的手段对燃烧室试验环境下单屏式多点气流温度传感器进行仿真计算,改变温场、流场环境,分析研究了来流总温、来流总压以及马赫数等工况参数对单屏式多点气流温度传感器的测量结果的影响规律,并用试验进行验证.数值模拟结果表明:在燃烧室试验环境下,单屏式多点气流温度传感器的测温偏差随着来流总温的增大而增大,每增加1000...     

Pressing effect in polymer solar cells with bulk heterojunction nanolayers

We report the effect of pressing light-absorbing layers on the performance of polymer solar cells. The light-absorbing active layer was prepared on the transparent conducting oxide coated substrates from solutions that contain a mixture of regioregular poly(3-hexylthiophene) and soluble fullerene molecules. The active layers were pressed using a home-built micro-press system by controlling temperature and pressure, followed by the top electrode deposition. The surface of the active layers pressed was examined using atomic force microscope, while the photovoltaic characteristics of devices were measured under simulated solar light illumination (air mass 1.5 G, 100 mW/cm2). Results showed that the dark current of devices was noticeably increased by pressing the active layer without respect to the pressing temperature. The highest power conversion efficiency was achieved for the device with the active layer pressed under 10 kgf at 70 degrees C. The result was explained in terms of surface morphology and thermophysical effect.     

Effects of various nitriding parameters on active screen plasma nitriding behavior of a low-alloy steel

Active screen plasma nitriding (ASPN) is a novel surface modification technique that has many capabilities over the conventional DC plasma nitriding (CPN). In this study, 30CrNiMo8 low-alloy steel was active screen plasma-nitrided under various nitriding parameters such as active screen set-up parameters (different screen hole sizes, mesh sheet and plate top lids) and treatment temperature (520, 550 and 580 °C), in the gas mixture of 75% N₂+25% H₂ and chamber pressure of 500 Pa for 5 h. The properties of the nitrided specimens have been assessed by evaluating composition of phases, surface hardness, compound layer thickness and case depth using X-ray diffraction (XRD), microhardness measurements and scanning electron microscopy (SEM). It was found that the screen hole size and top lid type (mesh or plate) play an important role in transition of active species (nitrogen ions and neutrals) toward the sample surface, which in turn can affect the nitrided layer hardness and thickness. Treatment at higher temperature with bigger screen hole size resulted in a thicker compound layer and higher layer hardness. The compound layers developed on the samples treated under different conditions were dual phase consisting of γ′-Fe₄N and ε-Fe_2-3N phases.     

基于离心机的低气压精密控制研究

针对惯性器件全量程气压灵敏度校准难题,发明了一种可抗高离心加速度的气压箱结构,并研制了离心-气压复合校准装置,实现了大g值条件下惯性器件气压特性的校准。本装置设计了两种工作模式:离心机静止时,利用真空泵、高精度压力传感器等气压精密测控系统实现离心-气压复合校准装置的精密控压;离心机工作时,通过密封技术等实现离心-气压复合校准装置保压。本装置通过对安装在离心机上的试验箱内气压进行精密控制,将高线加速度与气压环境有机结合在一起,为加速度计提供可靠的加速度、气压复合计量校准环境。实验结果验证了所设计的气压箱结构可以实现气压范围1~100 kPa,气压偏差优于10 Pa的精密控制。     

A CVD Process for Producing Atomic Current Sources Based on <Superscript>63</Superscript>Ni

A CVD process was developed for producing ⁶³Ni-based atomic batteries by deposition of active ⁶³Ni layers onto semiconductor silicon supports. Tetrakis(trifluorophosphine)nickel synthesized from ⁶³Ni metal and phosphorus trifluoride was used as the volatile precursor. The influence of the support temperature and working pressure on the characteristics of the ⁶³Ni coating was examined.     

Surface physical and chemical changes of pure iron after molybdenum ion implantation and their effects on the tribological behaviour II: Tribological behaviour

The components of tribological systems are all quite sensitive to the surface chemistry and microstructure of the tribological material which may be dramatically changed by ion implantation. This paper is aimed at studying the effect of surface physical and chemical changes caused by molybdenum ion implantation on the friction and wear behaviours of pure iron. For this purpose, the wear tests of unimplanted and implanted specimens were conducted on an SRV fretting wear machine in air, at room temperature and with or without lubrication. The surface morphology, composition and chemical state of the wear tracks were also examined using electron probe microanalysis, Auger electron spectroscopy and X-ray photoelectron spectroscopy. The experimental results indicate that the wear resistance of pure iron is largely improved by molybdenum ion implantation. Under dry friction conditions, the wear resistance of the specimen implanted with a dose of 3 × 10¹⁷ is increased to 2.8 times that of unimplanated pure iron since the anti-adhesion, anti-abrasion and anti-deformation abilities are improved as a result of the increase in microhardness. When liquid paraffin is used as a lubricant, the wear resistance of the implanted specimen is 4.8 times as high as that of the unimplanted one. This further increase in wear resistance compared with that for dry friction is mainly due to the boundary lubricating film provided by liquid paraffin, which reduces the adhesion between the wear counterpart and molybdenum atoms in the implanted specimen. When liquid paraffin plus sulphurized olefin is used as a lubricant, the wear resistance of the implanted specimen is 2.8 times as high as that of the unimplanted one. It can be seen that the increasing value of the wear resistance is lower than that of the sample lubricated with liquid paraffin. The reason is that the compounds FeS and FeSO₄ formed between the element of the wear specimen and the active elements of the lubricant in the wear process play an anti-wear role. However, the presence of a molybdenum element in the implanted specimen decreases the atomic ratio of iron, and thus decreases the amount of FeS and FeSO₄ and the wear resistance.     

Consequences of Ti-, Li-, and Er-ion implantations on the optical properties of single layers of Ta(2)O(5)

Tantalum pentoxide (Ta(2)O(5)) layers made by ion plating are implanted with a high fluence of keV Ti, Li, and Er ions. The resulting refractive-index profiles are given from the analysis of guided-wave propagation conditions. A comparison with spectrophotometric measurements is presented. All the implanted layers present low losses (extinction coefficient of some 10(-6)) after thermal annealing in air. Ti-implanted layers exhibit an increase in refractive index, whereas Li- and Er-implanted layers present a slight decrease in refractive index. Er-implanted layers present photoluminescent properties.     

Using Experimental Design to Optimize the Process Parameters in Fluidized Bed Granulation

In this study many parameters were screened for a small-scale granulation process for their effect on the yield of granules between 75 and 500 μm and the geometrical granule mean size (d50). First a Plackett-Burman design was applied to screen the inlet air temperature, the inlet flow rate, the spray rate, the nozzle air pressure, the nozzle spray diameter, and the nozzle position. The Plackett-Burman design showed that the key process parameters were the inlet flow rate and the spray rate and probably also the inlet air temperature. Afterward a fractional factorial design (2^5?2) was applied to screen the remaining parameters plus the nozzle aircap position and the spraying time interval. The fractional factorial design showed that the nozzle air pressure was also important. As the target values for the granule yield (between 75 and 500 μm) and the geometric mean granule size (between 300 and 500 μm) were reached during the screening experiments, further optimization was not considered necessary.     

A new hybrid ion exchanger: Effect of system parameters on the adsorption of vanadium (V)

The hybrid ion exchanger consisted of PONF-g-GMA anion fibrous exchanger and IRA-96 bead-type anion exchanger was developed by combining different types of layers with hot-melt adhesive. Its ion exchange capacity and the pressure drop with flow rate of water were measured and the adsorption of vanadium (V) ions on the hybrid ion exchanger was evaluated with various process parameters such as pH, initial concentration, and temperature. It was observed that the adsorption kinetics of vanadium (V) ions on the hybrid ion exchanger could be analyzed with pseudo-second-order model.     

温度和包装内缓蚀气压对金属气相防锈的影响

目的 通过电化学方法探究气相防锈包装过程中温度和包装内缓蚀气压对气相防锈效果的影响，为实际工况中获得较长的气相防锈有效寿命期提供数据参考。方法 以10^#钢和铸铁为金属试样作为工作电极，通过交流阻抗谱和动极化曲线对不同温度和不同缓蚀气压下试样缓蚀过程进行研究，并分析其电化学参数变化规律，对缓蚀效果进行评价和比较。结果 交流阻抗谱结果表明，温度升高和缓蚀气压下降时，金属试样表面阻抗值减小，且在高温低频区出现Warburg阻抗，腐蚀机理发生改变。动极化曲线结果表明，随着温度升高和缓蚀气压下降，金属试样的腐蚀电流减小，腐蚀电压负移。结论 温度升高及包装内的缓蚀气压下降均会造成金属气相防锈效果下降，且升温后缓蚀剂对缓蚀气压的变化更敏感，为延长气相防锈包装的有效寿命期应关注高温工况，并确保气相防锈包装内缓蚀气压稳定。