基体偏压对ZrN涂层微观结构及力学性能的影响

利用多弧离子镀技术通过改变基体偏压(-100,-150,-200 V)在SKD11模具钢基体上制备了一系列ZrN涂层。采用X射线衍射、扫描电镜、纳米压痕仪、划痕仪、摩擦磨损试验机和台阶仪等分析技术对涂层的结构、表面形貌、硬度、弹性模量、断裂韧性、结合力、摩擦磨损性能等进行表征,重点研究基体偏压对涂层微观结构和力学性能的影响。结果表明,在不同偏压条件下制备的涂层始终由ZrN相构成;随着基体偏压的升高,ZrN涂层生长的择优取向发生了改变,生长择优取向从低偏压下(-100 V)的(311)向(111)(-200 V)转变;硬度和结合力呈现先增后减的趋势,并在偏压为-150 V时达到最大值,分别为29.14 GPa和58 N;摩擦系数及磨损量均在偏压为-150 V时最低。     

偏压对磁控溅射TiB_2涂层结构和性能的影响

溅射镀膜过程中基体偏压对涂层的组织、结构和性能都有很重要的影响。本文采用脉冲磁控溅射技术在硬质合金基体上制备了TiB_2涂层,研究了不同衬底偏压(-50~-300 V)对涂层生长特性、结构和性能的影响。利用X射线衍射、扫描电子显微镜、能谱仪、X射线光电子能谱仪、纳米划痕仪、维氏硬度计对涂层的物相结构、表面形貌、化学成分、以及机械性能进行了分析。结果表明:在所有偏压下制备出的TiB_2涂层都呈现出六方结构,并且表现为显著的(001)择优取向;随着偏压的逐渐增大,(001)衍射峰强度呈先增强后减弱的趋势;基体施加低偏压时制备出的TiB_2涂层呈现出粗大的柱状生长结构,这时涂层较为疏松,裂纹和缺陷较多,硬度为2829 HV;随着制备过程中基体偏压的升高,涂层中的柱状生长结构逐渐细化,涂层变得越来越致密。这使得涂层硬度得到大幅提高,在偏压为-250 V时达到最大硬度值3820 HV。但随着偏压进一步增大到-300 V时,由于剧烈轰击产生的缺陷增多,涂层硬度反而下降。     

氧气流量对超音速火焰喷涂TiB2-40Co涂层组织和性能研究

采用超音速火焰喷涂技术在不同氧气流量条件下制备3种TiB2-40Co涂层,采用扫描电镜、X射线衍射仪研究了涂层的组织和相结构,运用压痕法测定了涂层的显微硬度,通过水淬法测试涂层的抗热震性能,并研究涂层的耐熔融铝硅腐蚀性能.结果表明,3种TiB2-40Co涂层具有叠层状结构,No.1涂层最为致密,其孔隙率仅为0.286%;涂层的主要物相为TiB2和Co;显微硬度值分别为697±60 HV0.3、523±86 HV0.3和648±38 HV0.3;No.1涂层具有最好的抗热震性能;经过120 h熔融铝硅腐蚀后发现,3种涂层均具有良好的抗熔融铝硅腐蚀性能,其中No.1涂层试样耐腐蚀性能最好.     

Cu,Ag,Ni掺杂TiB2基涂层的结构及韧性研究

采用磁控溅射方法分别掺杂含量约为10%(原子分数)的Cu,Ag,Ni金属,制备出三种TiB2基涂层。利用XRD,SEM分析涂层结构,并通过塑性指数δH、划痕和压痕三种手段对涂层韧性进行表征。结果表明:掺杂金属在涂层中的存在形式不同,导致对涂层晶粒和生长结构的影响不同,其中Ag以晶体形式存在,未发现Cu和Ni的晶相;三种涂层均存在TiB2晶相,Ni和Ag使TiB2晶粒细化,Cu促进晶粒长大;TiB2-Cu和TiB2-Ni涂层为柱状结构,表面存在明显颗粒,而TiB2-Ag涂层柱状结构趋于消失,表面无明显颗粒。结构的不同对涂层的力学性能有明显影响,所有涂层均保持在较高的硬度(>35GPa),三种金属都对涂层韧性有所改善,其中Ni最为显著,Cu和Ag相对较差。     

黏结相含量对超音速火焰喷涂TiB_2-Ni涂层组织和性能的影响

以机械合金化工艺制备的TiB2-40Ni和TiB2-50Ni粉末为原料,利用超音速火焰喷涂沉积不同TiB2-Ni涂层,采用扫描电镜、X射线衍射仪研究了涂层的组织和相结构,运用压痕法测定了涂层的显微硬度,通过水淬法测试涂层的抗热震性能,并研究涂层的耐熔融铝硅腐蚀性能。结果表明,TiB2-40Ni和TiB2-50Ni涂层致密,孔隙率分别为1.25%和0.12%;涂层的主要物相为TiB2和Ni;显微硬度值分别为(643.5±56.8)HV0.3与(597.9±36.1)HV0.3;涂层均具有较好的抗热震性能,其中以TiB2-50Ni涂层最佳;经过120h熔融铝硅腐蚀后发现,两种涂层均具有良好的抗熔融铝硅腐蚀性能,TiB2-50Ni涂层试样具有最好的耐腐蚀性能。     

射频磁控溅射法制备TiB2涂层及其性能分析

利用射频磁控溅射技术在硅和钢片上沉积了TiB2涂层.采用场发射电子扫描显微镜(FESEM),小掠射角x射线衍射(GAXRD)及X射线光电子能谱(XPS)分别研究了涂层的横截面形貌,晶体结构以及涂层中的元素和化学状态.同时,对涂层的显微硬度和残余应力进行了表征.结果表明, 利用射频磁控溅射法制备的TiB2涂层平整光滑,结构致密,沿[001]晶向择优生长,具有纳米晶结构,硬度显著提高,而且残余压应力较低.     

偏压对CrN/Si3N4纳米多层膜结构、硬度和断裂韧性的影响

利用磁控溅射法在不同基底偏压条件下制备了CrN/Si3N4纳米多层膜,分别用X射线衍射仪、原子力显微镜及纳米压痕仪表征多层膜的微观结构及力学性能,结果表明,衬底偏压对CrN/Si3N4纳米多层膜微观结构、界面结构、硬度和磨损性能有重要影响。漂浮电位时多层膜界面粗糙,CrN呈(200)、(111)共同生长,硬度和弹性模量低,有偏压且变化时界面宽度和粗糙度变化不大,硬度和模量变化的主要原因是不同衬底偏压下的晶格畸变导致两层材料弹性模量变化和晶粒尺寸变化。基底偏压的优化有助于改善涂层的屈服应力和断裂韧性。     

衬底偏压对CrN／Si3N4纳米多层膜结构和力学性能的影响

采用磁控溅射法在不同基底偏压条件下制备了CrN／Si3N4纳米多层膜,用x射线衍射仪、原子力显微镜及纳米压痕仪表征,结果表明,衬底偏压对CrN／Si3N4纳米多层膜微观结构、界面结构、硬度和磨损性能有重要影响;漂浮电位时,导致多层膜界面粗糙,CrN呈（200）、（111）共同生长,硬度和弹性模量低;当偏压变化时,界面宽度和粗糙度变化不大,硬度和模量变化的主要原因是不同衬底偏压下的晶格畸变导致两层材料弹性模量变化和晶粒尺寸变化。与漂浮电位相比,涂层的屈服应力和断裂韧性有所增强。     

气压及偏压对磁控溅射TaN薄膜力学性能影响

采用电子回旋共振增强磁控溅射在不锈钢基体上制备六方相TaN薄膜,并研究了气压及偏压对TaN薄膜结构、力学性能的影响.利用X射线衍射、扫描电镜、原子力显微镜分析薄膜化学结构及形貌,利用纳米压痕、划痕实验仪对薄膜力学性能进行测定.研究表明,制备气压上升影响六方TaN相择优取向,气压、Ar/N2流量比及偏压改变对TaN薄膜力学性能有较大影响.实验证明在1.1×10-1 pa,偏压100 V下制备的TaN薄膜具有最高硬度32.4 GPa,最高结合力极限载荷27N.     

负偏压对纯Cr涂层表面液滴及涂层结合力的影响

采用多弧离子镀技术于不同负偏压条件下在锆合金表面沉积纯Cr涂层。利用扫描电子显微镜、X射线衍射仪和划痕仪分析了纯Cr涂层表面形貌和择优生长取向变化规律,并对涂层膜基结合力进行表征。结果表明:负偏压不同,纯Cr涂层上液滴分布和择优生长取向都有较大的影响。其中随着负偏压的增加,纯Cr涂层表面液滴的数量和尺寸先减少后增加的趋势,同时纯Cr涂层晶体择优生长趋势由(200)晶面转向(110)晶面;纯Cr涂层的膜/基结合力随负偏压的增加逐渐增大。     

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.