氮气流量对UBMS制备TiN薄膜结构和力学性能的影响

利用非平衡磁控溅射离子镀技术研究了不同氮气流量对TiN薄膜结构、摩擦性能、附着力及显微硬度的影响.研究结果表明:N2流量对TiN薄膜的择优取向有很大影响,N2流量较小时,TiN薄膜显示出{111}择优取向生长趋势,在N2流量为15sccm条件下沉积的TiN薄膜的(111)衍射峰强度最强,与之对应的薄膜硬度和膜基结合强度最高,耐磨性能也最好;N2流量的大小对TiN薄膜的沉积速率和摩擦系数影响显著,并随N2流量增加都有较明显的下降趋势.     

非平衡磁控溅射沉积TiN/Ti-O复合薄膜机械性能研究

本文利用非平衡磁控溅射设备,采用四种不同的TiN到Ti-O的过渡方式,在Si(100)和Ti6A14V基体上制备了TiN/Ti-O薄膜.采用X射线衍射(XRD)分析薄膜的结构;使用AMBIOSXP-2台阶仪检测薄膜应力;利用XDl000B knoop型显微硬度仪、瑞士CSEM销盘摩擦磨损实验机、WS-97系统划痕实验机对薄膜的力学性能进行检测.结果表明,在钛合金表面制备TiN薄膜后,逐渐降低N2流量至0 sccm,沉积一层Ti膜,再用逐渐通入O2制备Ti-O薄膜的工艺制备的TiN/Ti-N/Ti/Ti-O薄膜具有较好的力学性能.     

高功率脉冲电流对磁控溅射TiN薄膜结构及力学性能影响

采用高功率脉冲磁控溅射技术在M2高速钢基体上沉积了TiN薄膜,研究了不同脉冲电流下TiN膜层的沉积速率、膜基结合力、晶体生长取向、纳米硬度和摩擦磨损性能等。结果表明:随着脉冲电流的增加,膜层沉积速率不断增大,膜层致密度逐渐增强。当脉冲电流增加到20A以上时膜层沿着(111)面择优生长并且具有最高的I_(111),这与能流密度效应有关。脉冲电流为20A时的膜层表面具有最高的硬度(可达25GPa)、最高的膜基结合力(可达70N,压痕评定优于HF2)和较好的耐摩擦磨损性能。     

高速钢上磁控溅射氮化碳薄膜的摩擦学性能研究

采用磁控溅射法在高速钢(HSS)基片上制备了氮化碳(CNx/TiN)复合薄膜,并采用球-盘式摩擦试验法对其摩擦学性能进行了研究.通过分析薄膜的摩擦系数变化曲线,并辅之以薄膜摩擦表面形貌的显微观察分析以及EDS微区成分分析,对薄膜的摩擦学性能进行了表征.结果表明,CNx/TiN复合薄膜与对偶球(Si3N4)之间的摩擦系数约为0.3.具有较好的减摩性能,但复合薄膜的耐磨性能受制备工艺的影响较大.沉积合适的TiN/Ti过渡层可以显著提高薄膜的耐磨性能.薄膜的磨损机理主要为磨粒磨损与黏着磨损以及疲劳磨损相互结合.     

微量Al掺杂对TiN微观结构及性能的影响

采用离子辅助增强磁控溅射与离子蒸发镀二元组合源设备在高速钢基体沉积出微量Al掺杂的TiN涂层(Al-TiN),利用扫描电子显微镜、X射线衍射仪、显微硬度计对涂层的组成成分、相结构、膜基结合力及显微硬度进行了分析;用摩擦磨损实验机及台阶仪分析了薄膜的摩擦磨损性能。研究了微量Al掺杂对薄膜的微结构及性能的影响。结果表明,TiN涂层中微量Al的存在使涂层的膜基结合力、耐摩擦磨损性能得到明显改善。     

微量Al掺杂对TiN微观结构及性能的影响

采用离子辅助增强磁控溅射与离子蒸发镀二元组合源设备在高速钢基体沉积出微量Al掺杂的TiN涂层(Al-TiN),利用扫描电子显微镜、X射线衍射仪、显微硬度计对涂层的组成成分、相结构、膜基结合力及显微硬度进行了分析;用摩擦磨损实验机及台阶仪分析了薄膜的摩擦磨损性能。研究了微量Al掺杂对薄膜的微结构及性能的影响。结果表明,TiN涂层中微量Al的存在使涂层的膜基结合力、耐摩擦磨损性能得到明显改善。     

TiN/Ti多层膜调制比对摩擦磨损行为影响的研究

考察了TiN/Ti多层膜调制比对其摩擦磨损行为的影响. 采用磁过滤阴极弧沉积的方法制备了具有不同调制比的TiN/Ti多层膜, 用扫描电镜和透射电镜对其层状结构及子层结构进行了观察和分析. 用纳米压痕和SRV摩擦磨损试验的方法, 对多层膜进行了纳米硬度和弹性模量测试以及摩擦磨损实验. 结果表明, 所制备的TiN/Ti多层膜层状结构清晰, 与基底结合良好, 调制比对多层膜的硬度和磨损特性影响较大, 而对摩擦系数的影响却不明显. 结合实验结果, 讨论了硬度与弹性模量的比值(H/E值)对TiN/Ti多层膜耐磨性的影响.     

直流磁控溅射Cr(Al)N薄膜的结构与性能比较研究

采用相同的基底偏压和靶基距离,以N2流量和靶材溅射功率为变量,以热作模具用钢H13和Si片为基底,用直流磁控溅射的方法沉积了CrN和CrAlN膜层.对这2种膜层用SEM测其表面形貌,用X射线衍射测其膜层结构,用M-400-H1测其表面显微硬度,用WS-97划痕仪测其膜层/基体之间的结合强度,用UMT-2摩擦磨损试验机测其表面摩擦磨损性能.在分析溅射变量对2种膜层的影响趋势的同时,也分析了Al元素加入后所获得的CrAlN与CrN在结构、力学性能(硬度和膜/基粘结强度)和摩擦性能上的变化趋势.     

TiN/Ti多层膜韧性对摩擦学性能的影响

考察了TiN/Ti多层膜韧性对其摩擦学性能的影响.采用磁过滤阴极弧沉积的方法制备了具有不同Ti子层厚度的TiN/Ti多层膜.用透射电镜对其层状结构及子层厚度进行了观察和分析,分别用Rockwell硬度计和UMT摩擦磨损试验机,进行了压痕测试和摩擦磨损实验.结果表明,TiN/Ti多层膜中Ti子层的加人显著提高了多层膜的韧性,相对TiN单层薄膜,当载荷较大时,多层膜的耐磨性有明显的改善.结合实验结果,讨论了TiN/Ti多层膜韧性对其耐磨性的影响.     

CrN/ZrN纳米多层膜的合成及其结构和性能的研究

利用非平衡直流磁控双靶溅射在不同的基底转速(4～11r/min)和不同反应气体流量下制备一系列的具有纳米周期的CrN/ZrN多层膜.利用X射线衍射,俄歇电子能谱,X射线光电子能谱表征了薄膜的成分和结构,利用纳米力学测试系统以及摩擦磨损仪测量了薄膜的机械性能和摩擦磨损性能,分析了基底的转速、反应气体的种类及流量对薄膜结构与机械性能和摩擦磨损性能的影响.结果表明在氮中混入适量氨气条件下合成的具有小纳米周期的多层膜,其硬度可达32 GPa,磨损率可低到0.3865×10-5mm3/Nm,明显优于单质薄膜.低角度XRD分析证明了薄膜的多层结构.     

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.