液态搅拌铸造颗粒增强Al－4％Mg复合材料的微观结构研究

本文以ＴＥＭ和ＥＤＳ为主要分析手段，研究了不同颗粒增强的Ａｌ－４％Ｍｇ复合材料的界面及其基体中的微观结构，探讨了它们的形成原因。结果表明：ＳｉＯ_２颗粒与基体间为反应结合，Ａｌ_２Ｏ_３和ＳｉＣ则基本上为机械结合。     

液态搅拌铸造颗粒增强Al－4％Mg复合材料的微观结构研究EI

本文以ＴＥＭ和ＥＤＳ为主要分析手段，研究了不同颗粒增强的Ａｌ－４％Ｍｇ复合材料的界面及其基体中的微观结构，探讨了它们的形成原因。结果表明：ＳｉＯ_２颗粒与基体间为反应结合，Ａｌ_２Ｏ_３和ＳｉＣ则基本上为机械结合。     

Si3N4/BN(f)复合材料的相界面

本文借助高分辩电子普微镜研究了Ｓｉ３Ｎ４／ＢＦ（ｆ）复合材料的相界面。研究发现，ＢＮ纤维的两端与基体结合牢固，界面不易解离，材料民裂过程中纤维很难拔出。材料的韩性主要通过ＢＮ纤维自身（００１）面上的滑移、撕裂和弯曲以及ＢＮ纤维的侧表与Ｓｉ３Ｎ４颗粒的颗上的解离等途径得以提高．     

碳化硅纤维增强铝基复合材料的界面组织研究EI

本文利用透射电子显微术（ＴＥＭ）和微区能谱分析（ＥＤＸ）对化学气相沉积碳化硅纤维增强ＬＤ２铝合金的界面结构进行了研究，并对显微组织与性能的关系进行了讨论。结果发现，用热压扩散工艺生产的ＳｉＣ／Ａｌ复合材料，其基体与ＳｉＣ纤维结合良好。界面处有棒状相Ａｌ＿４Ｃ＿３生成（该相是菱形结构，对纤维强度有较大破坏作用），且存在镁元素富集。     

热处理过程中纳米非晶Si－N－C粉的晶化及微结构变化研究

本文在１４７３～１９７２Ｋ温度范围内对激光合成的、平均粒径为３０ｎｍ的非晶Ｓｉ－Ｎ－Ｃ粉进行热处理（ｌａｔｍ．Ｎ２，１ｈ）；研究了粉体的晶化及微结构变化，结果表明，纳米非晶Ｓｉ－Ｎ－Ｃ粉具有短程有序的亚稳结构，此亚稳结构在＞１５２３Ｋ发生稳定团相分离，在１７７３Ｋ开始形成α－Ｓｉ３Ｎ４；β－ＳｉＣ，此时粒子间出现明显的表面扩散形成粒子簇；到１８７３Ｋ晶化加剧，α－Ｓｉ３Ｎ４和β－ＳｉＣ明显增多，并有少量的石墨碳形成。在１７７３～１８７３Ｋ，由固相分离形成α－Ｓｉ３Ｎ４／β－ＳｉＣ纳米复合结构。     

Si3N4／SiC纳米复合陶瓷的制备,结构和性能

Ｓｉ３Ｎ４／ＳｉＣＵ纳米复合陶瓷是近年发展起来的高温高温度结构材料，它通过纳米ＳｉＣ颗粒在Ｓｉ３Ｎ４基体中的弥散达到强化增韧的效果。研究表明，这种增韧方法所获得的室温和高温机械性能均远远高于其它的增韧方法。本文综述了Ｓｉ３Ｎ４／ＳｉＣ纳米复合陶瓷在制备、结构和性能方面的研究成果，指出了尚待解决的问题和今后的研究方向。     

SiCw＋B4Cp／MB15镁基复合材料力学性能与微观结构

对真空反压浸渍方法制备的挤压态ＳｉＣＷ＋Ｂ４ＣＰ／ＭＢ１５镁基复合材料及基体合金进行了一系列的力学性能测试，并用ＳＥＭ观察增强剂分布与断口形貌，用ＴＥＭ和ＥＤＳ方法对复合材料的界面结构进行分析。研究结果表明，上述复合材料同基体相比有更高的强度、弹性模量和比强度、比弹性模量。深浸蚀ＳＥＭ相分析表明均匀排布的晶须、颗粒起到很好的增强效果。复合材料的断口有晶须露头与韧窝存在，该复合材料具有一定的韧性；并在ＳｉＣ／ＭＢ１５界面上发现Ｚｎ析出相。     

硅粉在高压氮气中自蔓延燃烧合成氮化硅的反应机理

本文对Ｓｉ粉在高压氮气中自蔓延燃烧合成（ＳＨＳ）Ｓｉ３Ｎ４的反应机理进行了研究。燃烧反应中Ｓｉ以蒸汽形式与Ｎ２在Ｓｉ３Ｎ４晶种表面反应，反应分为两个主要阶段：（１）动力学反应阶段：Ｓｉ蒸汽不需经过扩散直接与Ｎ２进行反应，反应速度快；（２）扩散控制反应阶段：Ｓｉ蒸汽经过Ｎ２气层扩散到Ｓｉ３Ｎ４晶种表面与Ｎ２反应，反应受扩散控制，速度较慢。     

Si3N4／SiC（n）／SiC（w）纳米复合材料力学性能研究

采用热压烧结工艺制备了纳米ＳｉＣ颗粒和ＳｉＣ晶须协同补强增韧的Ｓｉ３Ｎ４基纳米复合陶瓷材料,并对其微观结构和力学性能进行了研究。结果表明：该复合材料室温抗弯强度达１０８０ＭＰａ,断裂韧性Ｋ１ｃ值达１１．７ＭＰａｍ＾１／２。纳米ＳｉＣ颗粒和ＳｉＣ晶须对Ｓｉ３Ｎ４基体具有较好的协同补强增韧作用。     

Si3N4薄膜的DC—PCVD沉积工艺及结构

用不附加另外电源的ＤＣ－ＰＣＶＤ装置沉积Ｓｉ３Ｎ４薄膜，，ＸＲＤ ＴＥＭ检查出这种Ｓｉ３Ｎ４是非晶态、ＩＲ，ＡＥＳ验证这种薄膜的主要成分是Ｓｉ３Ｎ４、ＴＥＭ与ＯＭ研究 薄膜组织结构。     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

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 Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Synthesis of Alumina-Zirconia Nanocomposites by Solgel Process

Al₂O₃-ZrO₂ nanocomposites were developed starting with the solgel process. Composite alumina-zirconia nanopowders were synthesized from metallorganic precursors (Aluminium secondary butoxide and zirconium Iso propoxide) using the solgel process. The parameters affecting the synthesis—solvent, concentration of precursor, R/H ratio (i.e., dilution of water in solvent)—were varied as also the temperature and pH. BET and TEM were used to measure nanosize. Diffuse reflectance spectroscopy and also qualitative optical absorption led to identical particle size estimate. The variation of process parameters was used to study the effect and interdependence of process parameters. Artificial Neural Networks was used to rigorously analyze the process. Although this led to confirmation of interdependence of parameters, the presence of a single overwhelming solvent variable was also established. Then the optimal process was used to synthesize more nanopowder. To produce bulk nanocomposite the nanopowders were sintered by varying the temperature and time period. The sintered lithoids were probed with a vickers hardness tester to measure elastic modulus, hardness, and fracture toughness. The results showed high elastic modulus, modest hardness, and very high fracture toughness.     

Friction Stir Processing Strategies for Uniform Distribution of Reinforcement in a Surface Composite

Friction stir processing (FSP) is an important technique for preparing surface composites. Fabricating defect-free surface composites with uniform particle distribution by FSP is a challenging task. In this study, silicon carbide particles reinforced AA5083 alloy surface composites was fabricated using different FSP strategies including variation in process parameters, dual-tool processing and tool offset overlapping. Material flow of the processed material with reinforcement particles demonstrated that the distribution of particles was influenced by the stirring action of the probe as well as the extrusion of the plasticized material due to the movement of the tool. Process parameters, particularly rotational speed, showed a dominant influence on the distribution of silicon carbide particles.     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

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.     

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