从二氰二胺的DMF溶液中电化学沉积氮化碳薄膜

首次采用二氰二胺的N,N二甲基甲酰胺(DMF)溶液做沉积液,用Si(100)和ITO导电玻璃做基底,在阴极上电化学沉积了CNx薄膜。X射线衍射(XRD)花样说明沉积的CNx薄膜为非晶结构。X射线光电子能谱(XPS)、傅立叶转换红外光谱(FTIR)分析结果表明CNx样品薄膜的N/C比为0.7左右,碳和氮主要以C—N、C=N的形式成键,有少量的碳和氮以C≡N的形式成键。电阻率测试显示,样品具有较高的电阻率,Si(100)和ITO导电玻璃基底上氮化碳薄膜的电阻率值范围分别为1011～1012Ω·cm和1012～1013Ω·cm。用Si(100)、ITO导电玻璃两种衬底,CNx薄膜的沉积速率、N含量和电阻率不同,说明衬底的选择对沉积过程和沉积膜的性能有重要影响。     

CNx薄膜的制备和光电性能

以单晶硅片(100)和镀Pt硅片为衬底,用电化学沉积方法在阴极制备出CNx薄膜(x接近于1),薄膜的表面平滑,颗粒均匀.热处理后得到了β-C3N4和α-C3N4多晶结构薄膜.热处理温度的提高使薄膜中的C≡N键逐渐减少而消失,氮元素的流失使薄膜中非晶碳的成分增多,但是薄膜中碳氮逐渐以sp3C-N为主.薄膜的能带在1.1～1.8 eV之间,氮含量对能带大小影响较大.热处理使薄膜的电阻率(高于108Ω@cm)变化不大.氮含量影响PL谱中3.0和3.5 eV处发射峰的峰强,不影响峰位.     

电化学制备CNx薄膜及其结构表征

在甲醇-尿素有机溶液中,采用电化学沉积方法,在单晶硅表面沉积得到掺氮的类金刚石薄膜.利用原子力显微镜、拉曼光谱、X射线光电子能谱、傅立叶分光红外光度计、X射线衍射仪研究了其表面形貌和微观结构.结果表明:电化学沉积得到的薄膜表面致密,但粗糙度较大;Raman光谱中出现明显的D峰和G峰,说明薄膜中存在无定形结构的碳基质;薄膜的化学元素组成主要为C,还有少量的N,C、N之间主要以单键和双键形式相连;薄膜中存在着一定数量的β-C3N4晶相.     

磁控溅射法制备CNx薄膜及其结构表征

以Ar/N2混合气体作为溅射气体,利用直流磁控溅射的方法制备子碳氮薄膜.利用X射线衍射和红外光谱对碳氮薄膜进行了结构分析.IR光谱证实了薄膜中碳氮化合物的形成,而XRD的检测结果表明,类石墨相g-C3N4是碳氮薄膜中的主要成分,同时有极少量的β-C3N4晶相生成.同时发现,Ar/N2溅射气体的分压对获取β-CsN4有着明显的影响.本实验中,当N2体积分数为33%,碳氮薄膜中β-C3N4晶相的含量最高.     

电化学沉积CNx薄膜的摩擦性能研究

以单晶硅片(100)为衬底,尿素-甲醇有机溶液为沉积液,用电化学沉积的方法在阴极制备出CNx薄膜.通过AFM、XPS、Raman光谱和FTIR光谱对得到的CNx薄膜的表面形貌和微观结构进行了表征,并在球-盘摩擦试验机上考察了薄膜的干摩擦性能,用SEM和EDS对摩擦表面进行了分析,研究了摩擦机理.结果表明薄膜表面致密,但粗糙度较大;Raman光谱中出现明显的D峰和G峰,说明薄膜具有无定形的结构特征;薄膜的化学元素组成主要为C,还有少量的N,C、N原子之间主要以共价单键和双键形式结合.CNx薄膜与红宝石球对摩时,摩擦系数随频率的增大而升高,但几乎不随载荷而变化;CNx薄膜在形成转移膜的过程中不仅失去了N,而且发生了石墨化,这与DLC膜的摩擦过程非常相似.     

真空阴极电弧沉积碳氮膜的研究

以氮气为反应气体，用真空阴极电弧沉积法沉积了CNx膜，并利用金相显微镜，Auger电子谱仪，FTIR及XRD对其进了分析，结果表明，真空阴极电弧沉积法可以制备含N量高，具有C＝N键和C－N键并含有晶态C3N4的CNx膜。     

离子束辅助脉冲激光沉积硼碳氮薄膜

以烧结B4C为靶材料、在氮离子束辅助下用脉冲激光沉积方法制备了三元化合物硼碳氮（BCN）薄膜.用X光电子谱和傅立叶变换红外谱方法表征了制备的薄膜.结果表明,膜层中包含B-C、N-C、B-N键等复合结构,以B-C-N原子杂化的形式结合成键,而并非各种成分的简单混合.还探讨了成膜过程和相关机理,离子束中的活性氮有效地和脉冲激光对B4C靶烧蚀产生的硼和碳结合成键,氮离子束的辅助还能在一定程度上抑制氧杂质进入膜层,给衬底适当加温有利于提高氮的含量并影响薄膜的化学结构.     

真空阴极电弧沉积碳氮膜的研究

以氮气为反应气体,用真空阴极电弧沉积法沉积了CNx膜,并利用金相显微镜、Auger电子谱仪、FTIR及XRD对其进了分析.结果表明真空阴极电弧沉积法可以制备含N量高、具有C≡N键和C-N键并含有晶态C3N4的CNx膜.     

磁控溅射掺碳TiB2薄膜的Raman光谱与摩擦行为

采用磁控溅射技术,使用SiC薄膜和Ti膜作为中间层在Cr12MoV钢表面制备掺碳TiB2(TiB2-C)薄膜,研究掺碳TiB2薄膜的Raman光谱、纳米压痕和摩擦行为。结果表明:溅射功率过高或过低都不利于掺入的C元素在薄膜中以DLC形式存在;C元素掺杂降低了TiB2薄膜的纳米硬度和弹性模量;以DLC形式存在的掺入的C能有效降低室温干摩擦(Si3N4球对摩件)条件下TiB2薄膜的摩擦因数。     

掺碳TiB2薄膜/钢摩擦副的干摩擦磨损性能

采用室温磁控溅射技术成功地在钢(Cr12MoV)基材表面制备出TiB2/SiC双层薄膜及掺碳TiB2(TiB2-C)/SiC双层薄膜,SiC薄膜为中间层。研究了掺碳对TiB2薄膜组织结构和摩擦磨损性能的影响。结果表明:SiC薄膜与基材和TiB2,TiB2-C薄膜间都具有明显且呈梯度的元素扩散;掺入的C以sp3C-C和sp2C-C形式存在,即以类金刚石形式存在;与钢球(直径为4 mm)对摩、干摩擦条件下,TiB2薄膜和TiB2-C薄膜的磨损速率在105mm3/(m.N)级,掺C明显降低了薄膜的摩擦系数(从0.82降低到0.45,5 min)和对对摩件(钢)的元素转移。分析表明,摩擦磨损性能的提高主要是TiB2-C薄膜中的C起到了固体润滑作用所致。     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.     

Study on Bond Ability of Arc-Spraying Coatings with Different Surface Pretreatment on Cast-Iron

Arc spraying coatings are widely used in various applications, but uncommon in cast iron substrate. Different surface pretreatment technology is tested on substrates of gray cast iron. Surface roughness and residual stress were measured by TR200 and X-ray diffraction analyzer. Influence of different surface pretreatment methods ( dry blasting and fusebond) on roughness and residual stress was analyzed. The arc-sprayed coatings of wire 3Cr13 (φ2mm) on gray cast iron substrate is studied. The microstructure and interface of bonding layer were observed by SEM. The bond strength was taken by tensile test. Results show that bond strength with grit blasting is higher than fuse-bond; it is feasible to make wire 3Cr13 coating with arc spraying on cast iron substrate roughened by grit blasting.     

Structural Characteristics of TiO2 Ceramic Coating by Micro-Plasma Oxidation

TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.     

Evaluation of fatigue life of steel using steel grain size

The insightful discussion of the relationship between the construction of metallographic and fatigue life and proposition of mathematical relationships describing this relationship was conducted in the paper. This paper presents a method for estimating the fatigue life, based on the construction of the microstructural material taking into account the grain size and the participation of ferrite and pearlite phase.