SYNTHESIS OF NANOCRYSTALLINE α-ALUMINA POWDER THROUGH WET-CHEMICAL ROUTE

以Ａｌ（ＮＯ３）３和ＮＨ３水为原料制备Ａｌ（ＯＨ）干凝胶，经煅烧合成了α－Ａｌ２Ｏ３纳米粉。Ａｌ（ＯＨ）３干凝胶煅烧过程中的物相变化顺序为Ａｌ（ＯＨ）３－γ－ＡｌＯＯＨ     

阴离子粘土LiAl2(OH)6X·2H2O(X=OH-,1/2CO32-)的离子交换特性

本文研究了阴离子粘土ＬｉＡｌ２（ＯＨ）６－Ｘ．２Ｈ２Ｏ（Ｘ＝ＯＨ＾－，１／２ＣＯ３＾２）的离子交换特性，结构分析表明，ＬｉＡｌ２－ＬＤＨ含水分隔层内的ＯＨ和ＣＯ３＾２－离子容易与酸性溶液中的Ｃｌ、ＮＯ３等离子进行交换，且保持ＬｉＡｌ２－ＬＤＨ的水滑石型层状结构不变，其中Ｃｌ－离子型表现较高的离子交换速率，在阴离子交换的同时，氢氧化以内的Ｌｉ＾＋离子也被Ｈ离子部分取代，但交换率较低，进一步讨论说明，     

Fe（OH）3中微量金属离子对水热合成α—Fe2O3粒径的影响

本文研究了某些金属离子（Ａｌ＾３＋、Ｍｎ＾２＋、Ｚｎ＾２＋、Ｃｒ＾２＋、Ｎｉ＾２＋、Ｃｏ＾２＋）Ｆｅ（ＯＨ）３凝胶经水热法合成的α－Ｆｅ２Ｏ３微粉颗粒大小的影响。研究结果出现，随着金属离子的浓度在一定范围内（０．０１０－０．０５０ｍｏｌ·Ｌ＾－１）的增加，α－Ｆｅ２Ｏ３颗粒有减小的趋势。其中加入Ｃｏ＾２＋（０．０５０ｍｏｌ·Ｌ＾－１）、Ｍｎ＾２＋（０．１００ｍｏｌ·Ｌ＾－１）可以得到粒径为７５ｎｍ     

氧化钇含量对Al2O3／Y—TZP复相陶瓷的影响

本文以ＺｒＯＣｌ２．８Ｈ２Ｏ、Ａｌ２Ｏ３及Ｙ（ＮＯ３）３为原料，用共沉淀法合成Ｙ２Ｏ３含量不同的ＺｒＯ２－Ａｌ２Ｏ３复合粉体，并采用热压工艺制备复相陶瓷。研究了氧化钇含量对复相陶瓷力学性能及应力诱导下氧化锆相变能力的影响。     

AlOOH对Al2O3直接凝固注模成型坯体强度等性能影响

为了改善直接注模成型（ＤＣＣ）氧化铝的坯体性能，在Ａｌ２Ｏ３－ＤＣＣ过程中加入ＡｌＯＯＨ本文详细研究了Ａｌ２Ｏ３＋ＡｌＯＯＨ体系的湿坯性能，干燥行为及烧结致密化过程，结果表明，少量ＡｌＯＯＨ加入可显著提高Ａｌ２Ｏ３的湿坯抗压强度和弹性模量，当ＡｌＯＯＨ体积含量〈３．０％时对干燥过程没有影响，干燥坯体经无压烧结后可获得烧结密度达３．９７ｇ／ｃｍ＾３（９９．７％ＴＤ）。显微结构均匀的α－Ａｌ２Ｏ３相。     

氧化钇含量对Al_2O_3／Y－TZP复相陶瓷的影响

本文以ＺｒＯＣｌ２８Ｈ２Ｏ、Ａｌ２Ｏ３及Ｙ（ＮＯ３）３为原料，用共沉淀法合成Ｙ２Ｏ３含量不同的ＺｒＯ２－Ａｌ２Ｏ３复合粉体，并采用热压工艺制备复相陶瓷．研究了氧化钇含量对复相陶瓷力学性能及应力诱导下氧化锆相变能力的影响．结果表明，氧化钇含量为１．８ｍｏｌ％时，复相陶瓷中氧化锆仍能全部保持为四方相，且在应力诱导下可相交量高达６４．６％，使材料呈现优良的室温和较好的高温力学性能．     

Naβ‘’—AlO3与水的作用

本文借用了Ｘ射线衍射相分析和热分析Ｍｇ或Ｌｉ稳定的Ｎａβ－Ａｌ２Ｏ３粉体和陶瓷在不同温度条件下与水发生的作用进行了系统地研究。实验表明，在密闭的常温条件下水主要以分子形式进入Ｎａβ－Ａｌ２Ｏ３的传导层内，形成水合物Ｎａβ－Ａｌ２Ｏ３．Ｈ２Ｏ；随着温度的升高，在β－Ａｌ２Ｏ３中将发生Ｈ３Ｏ＾＋与Ｎａ＾＋之间的离子交换，生成（Ｎａ＾＋，Ｈ３Ｏ＾＋）β－Ａｌ２Ｏ３．Ｈ２Ｏ；当温度进一步提高至２５０℃时，     

燃烧条件对自蔓延高温合成Al2O3/AlB12复相陶瓷粉体特性的影响

以铝、Ｂ２Ｏ３为原料,利用自蔓延高温合成（ＳＨＳ）制备了Ａｌ２Ｏ３／ＡｌＢ１２复相陶瓷粉体,研究了燃烧条件对粉体特性的影响。结果发现,经球磨处理后,复相陶瓷粉体中Ａｌ２Ｏ３的平均粒径为３￣４μｍ,ＡｌＢ１２的粒度为亚微米级。粉体的比表面积为￣１ｍ＾２／ｇ。     

镍－金刚石复合镀工艺

镍－金刚石复合镀工艺（攀枝花大学）工艺配方及条件ＮＩＳＯ４·６Ｈ２Ｏ２８０ｇ／ＬＮｉＣｌ２·７Ｈ２Ｏ６０ｇ／ＬＨ３ＢＯ３３５ｇ／Ｌ添加剂适量金刚石微粒（７～１０μｍ）４５ｇ／ＬｐＨ２．５～３．０电流密度２～３Ａ／ｄｍ２ｔ４０～５０℃电镀中有ＷＹＪ－３...     

燃烧合成AlN/ Y2O3陶瓷及致密化机理分析

采用ＳＨＳ工艺,在１００ＭＰａ的高压氮气下,制备了具有较高致密度的ＡｌＮ／Ｙ２Ｏ３陶瓷,结果显示,Ａｌ－Ｎ２－Ｙ２Ｏ３体系的ＳＨＳ过程中,当反应温度升至１７６０Ｃ时,Ｙ２Ｏ３与Ａｌ２Ｏ３形成共晶液相Ｙ３ＡＩ３Ｏ１２,发生液相烧结。随着Ｙ２Ｏ３含量的增加,上烧结作用增强２,产物致密度显著提高,抗弯强度及断裂韧性。Ａｌ－Ｎ２－Ｙ２Ｏ３主要发生在燃烧波蔓延方向,具有明显的方向性。     

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.