异种金属层状复合材料金相试样的制备技术

通过对金属层状复合材料金相试样制备经验的总结,介绍了异种金属层状复合材料界面金相试样制备过程中磨、抛光和侵蚀等关键操作,提出了在金相试样制备过程中应注意的事项和技术要点.实践表明,提出的制备技术具有技术上的合理性和可操作性,可得到较满意的样品.     

球墨铸铁金相试样的制备

介绍了球墨铸铁金相试样制备过程中的取样、磨制、抛光和侵蚀过程中的一些方法和技巧。实践证明,采用提出的金相试样制备方法,可快速制备高质量的金相试样。     

不锈钢与普通钢焊接件的金相试样制备方法

介绍了用电解侵蚀加化学侵蚀的方法制备不锈钢与普通钢焊接接头的金相试样，达到．能清晰显示金相组织的目的。该方法简便易行，效果较好。     

熔体浸渗法制备镁/氧化铝复合材料

采用熔体浸渗法制备了Mg/Al2O3复合材料,利用X射线衍射、扫描电镜、金相显微镜等测试手段对其微观组织结构和力学性能进行了表征,并对试样断裂韧性和耐磨性进行了研究.结果表明:熔体浸渗法制备的Mg/Al2O3复合材料具有双连续相网络结构,且界面结合良好;随着Mg含量的减少,复合材料断裂韧性降低、耐磨性大幅度提高.     

铁基粉末冶金零件常见生产缺陷的金相分析

介绍了铁基粉末冶金零件金相试样的制备工艺及侵蚀液的选用,并利用金相手段分析了几种铁基粉末冶金零件中的缺陷。结果表明:在粉末冶金的混粉、压制、烧结、热处理等过程中,存储及生产工艺不当均会造成零件产生缺陷,通过金相分析的方法检验缺陷件并与正常件进行对比,可找到引起缺陷的根本原因,从而指导生产、提高质量。     

玻璃纤维/191树脂复合材料水老化实验研究

利用手糊成型工艺方法制备了玻璃纤维/191树脂复合材料试样,研究了玻璃纤维/191树脂复合材料浸水前后的力学性能变化,并利用扫描电镜对试样断口形貌进行了观察,为树脂基复合材料的应用与发展提供了一定的依据.     

铝—锌单相合金定向凝固显微组织显示方法

介绍了铝－锌单相合金定向凝固显微组织的显示方法－机械抛光和电解抛光相结合制备金相样品，先用ｋｅｌｌｅｒ‘ｓ试剂浅侵蚀后，后用改型的Ｔｕｃｋｅｒ’ｓ试剂侵蚀，该方法简单，方便制备试样快速，可靠，正交偏振光下观察，显微组织清晰，层次分明。     

大块金属玻璃及其复合材料的粉末冶金成形研究进展

简要介绍了大块金属玻璃及其复合材料的研究现状及其应用领域.针对大块金属玻璃塑性低的不足,回顾了提高其塑性的原理和方法;通过对比铸造法,提出了粉末冶金法制备大块金属玻璃及其复合材料的成形原理和方法,进而详细介绍了电火花烧结、挤压、热压、扭转等方法制备大块金属玻璃及其复合材料的研究进展.最后,指出制备具有延性析出相的大块金属玻璃基复合材料将可能是未来粉末冶金法的研究趋势之一.     

网络陶瓷/金属复合材料的研究进展

介绍了网络陶瓷/金属复合材料近年来的发展.从网络陶瓷/金属复合材料体系出发,介绍了当前主要制备网络陶瓷的多种制备工艺和方法以及各种方法的优缺点;在制备复合材料的工艺中,介绍了无压浸渗和压力浸渗制备网络陶瓷/金属复合材料两种主要的材料复合方法,比较了无压和压力浸渗制备网络陶瓷/金属复合材料各自的优点和弊端;介绍了陶瓷/金属相的润湿类型以及通过添加元素、包覆及热处理等方法来改善金属对陶瓷的润湿;同时也介绍了复合材料中陶瓷与金属结合处的界面结构类型.总结了目前制备的网络陶瓷的不足之处,提出为了满足抗冲击材料的使用,制备网络陶瓷必须要解决的几个关键问题.     

钢铁零件Ni—Fe—W镀层的金相试样制备

介绍了钢铁零件Ｎｉ－Ｆｅ－Ｗ电刷镀层金相试样的制备方法。该方法具有制样迅速，棱边不倒圆、侵蚀结果重现性好、清晰显示镀层和基材组织等优点。     

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.