Co64Fe11Nb5Si12B8合金磁导率与温度的关系

采用铁芯测试仪测得合金样品的初始磁导率随温度的变化曲线, 用磁化强度小角旋转法测量非晶及晶化合金条带的饱和磁致伸缩系数λs;研究了不同温度退火后Co64Fe11Nb5Si12B8合金的磁导率随温度的变化、磁性以及磁致伸缩系数;结果表明:合金在580、590℃热处理磁性变好的反常现象是由于磁致伸缩系数变小所致.     

Fe-Ga超磁致伸缩材料的性能和中子衍射分析

Fe-Ga合金具有较大的磁致伸缩应变λ,低的饱和磁化场.Fe83Ga17饱和磁致伸缩应变可以达到3.00×10-4.为了进一步验证不同相结构对合金磁致伸缩性能的影响,对样品进行中子衍射和差热分析,发现Fe83Ga17合金在700℃附近存在相结构变化,结构变化导致合金磁致伸缩系数的改变.     

真空磁场热处理对Fe-Ga-Al合金磁致伸缩的影响

采用电弧炉熔炼方法得到Fe82Ga18-xAlx(x=3,9,12)合金的多晶样品。利用X射线衍射(XRD)和金相观察对合金的相组成进行分析,并对其磁致伸缩系数进行测量。经过真空磁场热处理后,对Fe-Ga-Al合金的结构和磁致伸缩性能进行研究。结果表明,真空磁场热处理后Fe-Ga-Al合金磁致伸缩系数均有提高,其中Fe82Ga9Al9合金经磁场热处理后,磁致伸缩达到114×10-6;Fe82Ga15Al3合金经磁场热处理后,其磁致伸缩增幅最大,比处理前增加165%。     

磁场退火对纳米晶Fe_(74.5)Cu_1Nb_2Si_(17.5)B_5合金饱和磁致伸缩系数和μi-T曲线的影响研究

研究了不同退火温度下形成的纳米晶Fe_(74.5)Cu_1Nb_2Si_(17.5)B_5合金经过磁场退火后,其饱和磁致伸缩系数λ_S、矫顽力H_C和μi-T曲线的变化。研究表明,经过磁场退火后,纳米晶合金的矫顽力出现不同程度的降低,温度在350℃以下时,初始磁导率表现出明显的提高,这些性能的改善归因于合金饱和磁致伸缩的减小。     

Fe_(64.7)Co_6Cr_(2.3)Mo_(2.5)B_(5.5)C_7Si_(3.3)P_(8.7)块体非晶合金的磁致伸缩特性

采用铜模吸铸法制备了直径2mm的Fe_(64.7)Co_6Cr_(2.3)Mo_(2.5)B_(5.5)C_7Si_(3.3)P_(8.7)块体非晶合金,其玻璃转变温度T_g、超冷液相区间ΔTx(=T_(x1)-T_g)、约化玻璃转变温度T_(rg)(=T_g/Tl)和玻璃形成能力参数γ(=T_(x1)/(T_g+Tl))分别为754,25K、0.595和0.3855。利用真空热处理炉分别在733K(T_g)、768K(T_g和T_(x1)之间)和803K(T_(x1))温度对块体非晶合金进行了等温退火,采用自制的电容法磁致伸缩测量装置测试了不同退火状态下的磁致伸缩特性,显示该非晶合金淬态下饱和磁致伸缩系数λ_s为9×10~(-6),随着退火温度的升高λ_s出现了先增后减的变化,磁致伸缩曲线形状也发生先变窄后变宽的变化。在733K退火样品的软磁性能最好,饱和磁致伸缩系数λ_s(=12×10~(-6))最高。     

《533》轴向取向稀土超磁致伸缩合金棒的制备与性能

利用非自耗真空电弧熔炼炉,通过恰当控制熔炼温度和热流方向,成功生长了具有<533>轴向取向的多晶稀土-铁系超磁致伸缩合金棒材.对其磁致伸缩性能测试结果表明,所制备的棒材具有较高的磁致伸缩应变,在0MPa压应力、400 kA·m-1的磁场下,其轴向饱和磁致伸缩系数λ//达1045×10-6,饱和磁致伸缩系数As为856×10-6.X射线衍射结果表明,该材料在轴向主要有(533)强衍射峰,同时还具有(311),(110)等弱峰;径向则有(110),(220),(311),(511)等衍射峰,但各峰强度均很弱,证明该方向上的取向性不如轴向.另外,本实验还对超磁致伸缩材料的磁滞同线进行了测试分析.     

热处理对磁致伸缩波导丝性能的影响

以Ni-Fe为主要成份制备磁致伸缩波导丝,研究了热处理对合金棒和波导丝性能的影响.试验表明,热处理后的合金棒软磁性能得到改善,饱和磁致伸缩系数能提高4.0×10-5左右;波导丝热处理后热弹系数能从负上升到零,弹性模量随着热处理温度的升高先升高后降低,而热处理温度对波导丝热膨胀系数基本没影响.     

铁镍基高温磁致伸缩合金研制

介绍了磁致伸缩效应、本质及磁致伸缩材料的应用,并对新型铁镍基高温磁致伸缩合金进行了成分设计和制备,研究表明,新型铁镍基磁致伸缩合金,具有高居里温度,较大的饱和磁致伸缩系数,较小的饱和磁化场,较小的热膨胀系数和良好的力学性能.     

制备方法对钴铁氧体的微观结构和磁性能的影响

钴铁氧体由于其独特的磁特性,如较大的饱和磁致伸缩应变、较高的电阻率、较高的应变和压力敏感度等,被广泛应用于换能器、传感器等领域,是一类重要的磁性功能材料,其中,饱和磁致伸缩系数 λS和压磁系数(dλ/dH)max是决定磁致伸缩材料在实际应用中器件性能的关键参数,其与化学成分和合成方法等多种因素密切相关.综述了钴铁氧体的...     

粘结Sm-Dy-Fe合金的磁致伸缩性能研究

采用粘结法制备了Sm_(1-x)Dy_xFe_2合金样品,测量了粘结合金样品的静态磁致伸缩、动态磁致伸缩系数、增量磁导率和磁-机械耦合系数,研究了磁致伸缩性能等随磁场H的变化规律。发现当x<0.12时合金的低场磁致伸缩随x的增加而增加,高场磁致伸缩随x的增加而降低。棒状Sm_(0.88)Dy_(0.12)Fe_2合金在H=200kA/m时的磁致伸缩达405×10~(-6),磁-机械耦合系数和动态磁致伸缩系数分别达到0.34和1.28nm/A,因而粘结Sm_(0.88)Dy_(0.12)Fe_2合金具有一定的实用价值。     

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.     

Effect of Permeable Crystalline Material on Steel Reinforcement Corrosion of Concrete

Permeable crystalline materialcan permeate into pores and cracks of concrete and catalyze the reaction between Ca(OH) 2and unhydrated cement to generate a great quantity needle non-soluble crystals, which can stop up the pores and cracks of concrete, and increase the impermeability of concrete. This paper reported the results of a study conducted to evaluate steel reinforcement corrosion of concrete specimens uncoated and coated with permeable crystalline material as well as mixed with the permeable crystalline material. The properties evaluated for corrosion test were water impermeability, water absorption, compressive strength and potential. The results of water impermeability, water absorption, compressive strength clearly showed that the permeable crystalline material could prohibit water, any soluble salts and moisture from penetrating the concrete to cause corrosion, leaking, and other problems, and it did increase the compressive strength, which was favorable for protection of corrosion of reinforcing steel. Moreover, it was concluded from the potential-time curve that the steel reinforcement of uncoated specimen was in the state of activation whereas that of other specimens coated and mixed with the permeable crystalline material was in the state of inactivation. Above all, it was indicated that the permeable crystalline materialis very effective to protect the steel reinforcement of concrete from corrosion.