添加燃烧合成晶种SPS烧结Yb α-SiAlON陶瓷

通过燃烧合成技术制备单相Ybα-SiAlON粉体，然后作为晶种添加到原料中利用SPS技术快速烧结出致密Ybα-SiAlON陶瓷．对SPS烧结过程中试样的致密化、相转变和形貌发育进行了研究，并探讨了添加晶种对烧结产物相组成和微观形貌的影响．实验结果表明，SPS可使试样迅速完成致密化过程，适当的烧结温度和保温时间可以促进相转变和晶粒发育．添加晶种，不仅促进了相转变过程，而且可以在烧结体内获得柱状晶，有助于改善材料的韧性．     

放电等离子烧结(SPS)技术

放电等离子烧结（SPS）技术是一种新型的材料制备技术。介绍了SPS技术的发展概况、原理、特点及在材料制备领域的应用。最后，对SPS主发展前景进行了展望。     

放电等离子烧结技术及其在陶瓷制备中的应用

综述了放电等离子烧结(SPS)技术在国内外的发展概况,简单介绍了SPS系统的基本配置,深入探讨了SPS的烧结机理及其技术特点,着重介绍了SPS技术在制备高致密度、细晶粒陶瓷等方面的应用,并对燃烧合成氮化硅粉体进行了放电等离子烧结的试验研究,得到了机械性能优于热压烧结的氮化硅陶瓷.结果证明放电等离子烧结在陶瓷的快速致密化中显示出了极大的优势,是一项有重要使用价值和广泛前景的新技术.     

熔体旋甩法制备Zn4Sb3热电材料微结构的研究

采用真空熔融-熔体旋甩-退火-放电等离子烧结（SPS）工艺制备了单相β-Zn4Sb3块体热电材料。对退火前后的薄带和SPS烧结后块体材料的相组成和微结构进行了分析和表征。结果表明：熔体旋甩后分相的薄带在退火后转变成主相为Zn4Sb3的薄带，退火薄带SPS烧结后得到了致密的β-Zn4Sb3块体材料；冷却速率和退火工艺对薄带自由面和与Cu辊接触面的物相和形貌变化影响较大；该工艺制备的β-Zn4Sb3块体热电材料致密，晶粒尺寸细小，约为50-80nm。     

放电等离子烧结(SPS)制备金属材料研究进展

综述了放电等离子烧结(SPS)技术在制备纳米/超细晶、大块非晶、准晶、金属间化合物、功能梯度材料、多孔材料、硬质合金等多种金属材料中的应用情况.重点阐述烧结过程中的致密化机理,焦耳热生成机制,关于等离子活化效应的争议,电流、温度、位移量和应力分布的不均匀性及其影响,粉末的预处理工艺及其对性能的影响.并总结了SPS技术现存问题及发展趋势.     

放电等离子烧结(SPS)技术与新材料研究

放电等离子烧结(SPS)作为一种材料的绿色制备新技术,正成为国内外材料领域的研究热点.介绍了SPS的工艺特点和装置、国内外发展状况以及特殊的烧结机理;阐述了SPS在功能梯度材料、生物材料、超细或纳米晶WC-Co硬质材料、镁合金等新材料制备方面的应用及优势.最后分析了SPS技术亟待解决的问题和今后的发展趋势.     

纯稀土纳米晶Gd块体材料的结构与磁性

采用放电等离子烧结技术（简称SPS技术）及热处理制备了全致密纯稀土纳米晶Gd块体材料，研究了材料的微结构和磁性。X衍射结果表明材料在烧结过程中形成了一定程度的c轴织构。TEM观察显示，烧结态纳米晶Gd的平均晶粒尺度在10nm左右；热处理后，平均晶粒尺寸达到100nm。PPMS测试发现与粗晶Gd相比，纳米晶Gd的居里温度以及饱和磁化强度均有所下降。说明Gd的纳米化对其磁性具有重要影响。     

TiB2陶瓷活化烧结及制备技术

TiB2材料具有高熔点、高硬度、耐磨、耐腐蚀、抗氧化以及导电性好和导热性好等优点,是一种具有广泛应用前景的新型陶瓷材料.但是其极强的共价键晶体结构和较低的自扩散系数,使得其很难获得致密的陶瓷材料.主要从添加助烧剂和烧结技术两方面介绍了TiB2陶瓷活化烧结方法的研究进展,并分析了该技术促进材料烧结致密化的机制,同时介绍了热压烧结和放电等离子(SPS)烧结技术.     

特种陶瓷材料快速烧结新技术研究

特种陶瓷作为工程材料的重要组成部分具有广阔的工业应用前景。传统烧结方法制备的特种陶瓷晶粒粗大且性能较差,高耗能和高耗时的特点也不符合绿色可持续发展的要求。快速烧结新技术的发展为这一难题提供了解决方法,利用快速烧结技术,陶瓷材料的制备时间和能耗大大降低,同时其在烧结过程中的晶粒生长也受到抑制,材料性能得以优化。主要围绕放电等离子体烧结(SPS)、高温自蔓延烧结(SHS)和基于这两种技术发展的烧结新方法(SPS Plus, SHS Plus),从烧结机理和实际应用的角度总结了特种陶瓷材料快速烧结新技术的发展。研究表明快速烧结新方法在快速制备、陶瓷连接、梯度和纳米陶瓷制备方面有独特的技术优势。     

放电等离子烧结中颈部形成机理探讨

放电等离子烧结(Spark Plasma Sintering,简称SPS)是一种新的固体压缩烧结技术,它具有升温速度快、烧结时间短、冷却速度快、外加压力和烧结气氛可控、节能环保等鲜明特点,成为材料发展和组织优化的有力工具.SPS在材料制备中的应用越来越广泛,但现阶段对SPS烧结过程的认识远未形成统一观点.SPS过程中颈部的形成是一个关键的阶段,影响到整个烧结过程.本文针对火花等离子烧结颈部的形成机理进行分析认为(1)在SPS烧结非金属材料过程中颈部的形成机理可能是塑性变形和蠕变;(2)导电材料烧结颈部形成过程中可能有火花放电现象发生,其主要机理可能是熔化和凝固、塑性变形、蠕变.同时,本文以纯铜为例,对其SPS烧结过程和结果进行了分析,对烧结过程中颈部的形成情况进行观察,并给出了解释.     

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.     

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.     

The Research and Application About "Dry Peeling Off" Technology for Airplane Surface Paint Layer

In this paper, the principle of spurting take off lacquer were introduced; and with orthogonal method the unsaturate polyester was prepared ;it was easy to peel airplane paint layer off with this material and equipment.     

Quality Study of Honeycomb Core Shaping Without Wax Stabilization

Sandwich panels utilizing honeycomb cores result in lightweight, high-strength units that are very rigid. Indeed, they give honeycomb panels the best strength-to-weight ratio of any construction type available. Conventionally, the wax is poured into the cell of the core to strengthen the structure and prevent the core from being crushed during milling. Much time and labor is required to wax, mill, and clean the cores. In this study, the process of pouring wax into the core was skipped. In other words, the cutter directly milled the core. Experiments showed that the compressive strength of the core produced without wax stabilization was only 3% lower than that of cores produced using the traditional method. In addition, the drum peel strengths of cores produced without wax stabilization were 38.4% higher than cores produced using the traditional method, in which residual wax seriously polluted the adhesive. It was also found that eliminating the wax process can reduce costs.     

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.     

In-process thermal treatment of polylactic acid in fused deposition modelling

Polylactic acid (PLA) is one of the most widely used open source fused filament fabrication materials due to its ease of extrusion, biodegradability, and mechanical strength. The mechanical strength of PLA largely depends on the proper growth of its semi-crystalline structure, which can be severely impaired by a low rate of crystallization, particularly in open source printers. This can be further aggravated by the non-uniform thermal distribution of heat that causes improper curing among the extruded beads of the printing material. As a result, PLA printed on open source printers does not achieve the best mechanical properties. This research, for the first time, proposes an additive-free solution implemented through a detailed set of experimentation to improve the curing rate through in-process temperature variations to cure the joints among the beads. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy is used to confirm the improvements in the bead joints. This work is conducted in two phases of experiments. In the first phase, a full factorial ANOVA is used to investigate various process parameters and the important variables are used in the second phase to print test specimens in four different sets.     

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.