离子注入纯Fe表面微观结构研究

本文应用透射电镜等方法对纯Ｆｅ中注入Ｎｉ＾＋，Ｍｏ＾＋，Ｂ＾＋及Ｎｉ＾＋＋Ｍｏ＾＋＋Ｂ＾＋起表面层微观结构变化进行了研究，同时对不同注入条件进行了计算机模拟计算。     

离子注入对Cr12MoV钢表面组织结构和力学性能的影响

研究了Ｃｒ１２ＭｏＶ钢离子注入层的显微组织特征及其对表面性能的影响。结果表明，离子注入使Ｃｒ１２ＭｏＶ钢的表面硬度和耐磨性能得到显著改善，且存在着一个最佳的注入剂量，约为３×１０＾１＾７Ｎ＾＋／ｃｍ＾２左右。离了注入在Ｃｒ１２ＭｏＶ钢表面层中形成了大量细小弥散的第二相粒子，并使α－Ｆｅ晶格发生严重畸变，从而引起材料表面强化。     

Mo＋C双元离子注入65Nb钢表面的研究

利用ＭＥＶＶＡ源引出Ｍｏ离子和Ｃ离子,对６５Ｎｂ钢进行不同剂量的离子注入,通过硬度测量、ＸＲＤ、ＡＥＳ等方法研究了注入前后６５Ｎｂ钢改性层的性能、成分及相组成的变化。试验发现Ｍｏ＋Ｃ双元离子注入,可在６５Ｎｂ钢注入层形成弥散的Ｆｅ２ＭｏＣ相,这是使该种基体钢经离子注入后表面硬度显著提高的重要原因。     

316L不锈钢表面氮离子注入后的疲劳及腐蚀疲劳行为

３１６Ｌ（Ｆｅ－１７．５Ｃｒ１３．５Ｎｉ－２．５Ｍｏ）不锈钢注入Ｎ离子后，其自由腐蚀电位Ｅ＿０、孔蚀再钝化电位Ｅ＿ｐ及孔蚀电位Ｅ＿ｒ均大大提高。在大应变量下，疲劳寿命下降；在小应变量下，疲劳性能改善。在电位Ｅ＿０作用下，其腐蚀疲劳寿命较高子注入前有所降低。在施加电位Ｅ＿０－１００ｍＶ时，其疲劳寿命较离子注入前提高。表面离子注入层的存在提高材料的循环应力。     

Cu层和Mo层对NiFe多层膜巨磁电阻（GMR）的影响

采用磁控溅射方法制备了ＮｉＦｅ／Ｃｕ和ＮｉＦｅ／Ｍｏ两个系列的多层膜，进行了结构，磁性和磁电阻测量，并对部分ＮｉＦｅ／Ｃｕ多层膜样品作了电镜分析，对于ＮｉＦｅ／Ｃｕ多层膜，在室温下的测量到巨磁电阻随Ｃｕ层厚度振荡的第一，二三峰。在ＮｉＦｅ／Ｍｏ多层膜样品中未发现巨磁电阻效应，讨论了非磁性 多层膜的磁性，界面结构和巨磁电阻效应。     

离子注入硼、氮后纯铁表层的组织结构与性能

本文对纯铁进行了硼、氮离子注入试验，利用透射电镜和ｘ射线衍射仪分析了纯铁注入层的组织结构，而且对纯铁注入层的硬度和耐蚀性进行了测试。结果表明：纯铁注入硼离子后表层形成了弥散的ＦｅＢ相，晶界处形成了较粗大的Ｆｅ２Ｂ相；注入硼离子后再注入氮离子进一步形成了Ｆｅ２Ｎ和Ｆｅ３Ｎ相。硼、氮离子注入明显提高表层的硬度，显著地提高纯铁表层的耐蚀性。     

氧缺位铁酸盐MFe2O4—δ的制备条件研究

使用ＸＲＤ、Ｍｏｓｓｂａｕｅｒ谱结合化学分析考查了５７３Ｋ下还原时间对空气氧化碱性悬浮液合成的铁酸盐ＭＦｅ２Ｏ４＋δ（δ≥０）的物相、晶格常数及化学组成的影响，得出了制备氧缺位铁酸盐ＭＦｅ２Ｏ４－δ（δ＞０）的最佳条件。结果表明，在５７３Ｋ下制备ＭＦｅ２Ｏ４－δ的最佳还原时间按Ｆｅ、Ｃｏ、Ｍｎ、Ｎｉ顺序分别为１０ｈ、３ｈ、４０ｍｉｎ和３０ｍｉｎ，氧缺位程度及晶格常数在最佳还原时间之前随还原时间增长而增大，在接近最佳还原时间时达到极大值。ＭＦｅ２Ｏ４－δ的极大值δ按Ｆｅ、Ｃｏ、Ｍｎ、Ｎｉ顺序减小，超过最佳还原时间ＭＦｅ２Ｏ４－δ将分解为α－Ｆｅ（Ｍ＝Ｆｅ）或ＭＯ－ＦｅＯ（Ｍ＝Ｃｏ、Ｍｎ、Ｎｉ）。     

NiFe／Cu和NiFe／Mo多层膜的界面结构与巨磁电阻

采用磁控溅射方法制备了ＮｉＦｅ／Ｃｕ和ＮｉＦｅ／Ｍｏ多层膜。测量了厚度不同的Ｃｕ层和Ｍｏ层多层膜的磁性和磁电阻,并用电镜分析了部分ＮｉＦｅ／Ｃｕ多层膜样品。测量到ＮｉＦｅ／Ｃｕ多层膜的室温巨磁电阻随Ｃｉ层厚度振荡的第一、二、三峰。而在ＮｉＦｅ／Ｍｏ多层膜中未发现巨磁电阻效应。讨论了多层膜的界面结构对巨磁电阻效应的影响。     

代位原子在Fe3Al亚点阵中的占位与合金的塑性

采用中子衍射法测定了Ｃｒ、Ｍｏ、Ｔｉ、Ｎｉ、Ｍｎ、Ｓｉ等代位原子在ＤＯ３结构Ｆｅ３Ａｌ亚点阵中的原子占位，并从解离能角度探讨了原子对之间的相互作用及合金室温塑性的影响，结果表明：Ｃｒ、ＭＯ、Ｔｉ都占据了Ａｌ原子的次近邻位置，替代Ｆｅ原子；Ｎｉ、Ｍｎ占据Ａｌ原子的最近邻位置，（Ｓｉ＋Ａ）当量成分以内的Ｓｉ原子替代占据Ａｌ原子的位置，由于Ａｌ－Ｃｒ原子对的结合能低于Ｆｅ－Ａｌ，ＡＬ－Ｍｏ用Ａｌ－Ｔｉ对     

300KeV氩离子辐照非晶态合金两代表面发泡形成

室温下，用３００ＫｅＶ氩离子辐照了非晶态合金Ｆｅ４０Ｎｉ４０Ｐ１２Ｂ８、Ｆｅ４０Ｎｉ４０Ｓｉ１２Ｂ８、Ｆｅ３９Ｎｉ３９Ｖ２Ｓｉ１２Ｂ８和Ｆｅ３９Ｎｉ３９Ｍｏ２Ｓｉ１２Ｂ８，研究了表面形貌随剂量的演变。在所研究的１．０×１０１７到５．０×１０１７离子／Ｃｍ２的剂量范围，表面形貌以发泡形貌为主，并观测到了两代表面发泡的形成，第二代表面发泡的直径与第一代发泡相比，明显减小。溅射自始至终影响着表面形貌，溅射对表面发泡的腐蚀抑制了剥落、层离等表面腐蚀的出现。当剂量增加到足以溅射掉第一代表面发泡时，针孔形成，针孔的密度随剂量增加而增加。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

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.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

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...     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

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.     

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.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...