机械合金化Cu—9Ni—6Sn合金的时效

本文对机械合金化法制备的Ｃｕ－９Ｎｉ－６Ｓｎ合金的时效过程研究后发现，时效时发生调幅分解的临界温度为４００－４５０℃。时效前施加一定冷形变量能够加速合金时效强化过程的进程，而且还提高了时效后硬度值。     

高弹性导电合金Cu—Ni—Sn的研究现状

Ｃｕ－Ｎｉ－Ｓｎ合金是调幅分解强化型合金。本文综述了Ｃｕ－Ｎｉ－Ｓｎ合金的研究现状，对材料的制备，热处理工艺，合金的强化机理，微观结构，性能，及它们在电子工业中的应用作了介绍。     

Ti—Ni形状记忆合金DSC曲线的特征

系统研究了Ｔｉ－Ｎｉ形状记忆合金时效后ＤＳＣ曲线的特征。结果表明，Ｔｉ－Ｎｉ合金的ＤＳＣ曲线分６种类型复杂ＤＳＣ曲线可用不完全循环法分析。根据成分时效工艺不同，Ｔｉ－Ｎｉ合金可发生７种可逆相变。     

时效温度对Fe-Mn-Si-Cr-Ni-C合金形状记忆效应的影响

研究了时效温度对Ｆｅ－１４Ｍｎ－５Ｓｉ－４Ｎｉ－０．２Ｃ记忆合金形状记忆效应,力学性能和显微组织的影响。结果表明：合金的形状回复率随时效温度的升高而增加,在１２２３Ｋ时达到最大值,比固溶态提高了６８％;随后形状回复率随时效温度的进一步升高而急剧下降。时效温度对合金硬度的影响与其对形状回复率得一致的。能谱和波谱分析表明时效析出的第二相是富铬,富锰和富硅的（Ｆｅ,Ｍｎ,Ｓｉ,Ｃｒ）３Ｃ合金渗渗碳体,且     

P—Si上电沉积非晶Ni—W—P薄膜的耐蚀性研究

对Ｐ－Ｓｉ上电沉积Ｎｉ－Ｗ－Ｐ合金薄膜在３％ＮａＣｌ、０．５ｍｏｌ·ｄｍ＾－３Ｈ２ＳＯ４、１ｍｏｌ·ｄｍ＾－３ＨＣｌ介质中的阳极溶解行为进行了研究,ＸＰＳ分析了钝化膜中各元素的化学价态和存在形式。结果表明,非晶Ｎｉ－Ｗ－Ｐ合金薄膜的耐蚀性远优于晶态Ｎｉ－Ｗ－Ｐ薄膜和非晶Ｎｉ－Ｐ薄膜;高Ｗ含量的非晶Ｎｉ－Ｗ－Ｐ合金薄膜,有较强的耐蚀能力;在ＮａＣｌ介质中非晶Ｎｉ－Ｗ－Ｐ合金形成了由Ｎｉ２Ｏ３、ＮｉＨ     

离心喷射成形Ti—48Al—2Mn—2Nb合金的变形特征

研究了离心喷射沉积（ＣＳＤ）成形的Ｔｉ－４８Ａｌ－２Ｍｎ－２Ｎｂ合金的形变,断裂过程及表面裂纹的特征,ＣＳＤ合金形变时可能发生了以层片作为滑移单元沿层片间界面的滑动;ＣＳＤ合金压缩变形量可超过２５％,但在压缩变形量仅１％时,就又观察到了微裂纹的萌生,裂纹与层片方向成一一夹角,与压缩方向平行。     

FeMnSi形状记忆合金成形加工性分析

ＦｅＭｎＳｉ系形状记忆合金由于层错能低难以实现交滑移,因此,其成形加工性很差,成材率低,这是阻碍ＦｅＭｎＳｉ系形状记忆合金实现产业化的关键问题之一。本文通过测试Ｆｅ－１７Ｍｎ－５Ｓｉ－１０Ｃｒ－５Ｎｉ形状记忆全金不同温度、不同应变速率和变温下的应力应变曲线,分析了合金的成形加工性。结果表明,升高温度并控制应变速率可显著改善合金的成形加工性;在实际生产中,合金可在９５０￣７００℃之间进行变温成形加工     

含碳Fe—Mn—Si—Cr—Ni合金形状记忆效尖的研究

研究了碳加入后对Ｆｅ－１４Ｍｎ－５Ｓｉ－８Ｃｒ－４Ｎｉ合金形状记忆效应（ＳＭＥ）的影响。结果表明，碳元素的适当加入，有助于合金的可恢复应变的提高。在３．７５￣７．５％变形量时，含碳量为０．１２％的合金的可恢复应变量可达２．５￣３％，高于超低碳合金（Ｃ〈０．０２％）。     

高弹性导电合金Cu-Ni-Sn的研究现状

Ｃｕ－Ｎｉ－Ｓｎ合金是调幅分解强化型合金。与铍青铜相比，该合金性能优良、价格便宜，因此是一种很有发展前途的铜基弹性材料。本文综述了Ｃｕ－Ｎｉ－Ｓｎ合金的研究现状，对材料的制备、热处理工艺、合金的强化机理、微观结构、性能、及它们在电子工业中的应用作了介绍。     

时效温度对Fe-Mn-Si-Cr-Ni-C记忆合金回复应力的影响

研究了时效温度对Ｆｅ－１４Ｍｎ－５Ｓｉ－８Ｃｒ－４Ｎｉ－０．２Ｃ记忆合金回复应力的影响。结果表明：合金经变形后加热时产生的最大回复应力σｈ随时效温度的升高而增加,在１０２３Ｋ达到最大值,比固溶态增加了７５％;随后σｈ将随时效工的进一步升高迅速下降。但是当时效温度高于１１２３Ｋ后,时效温度的进一步升高对σｈ几乎没有影响。时效后合金加热时产生的最大回复应力都大于固溶态时的回复应力。时效温度对合金加热后     

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.     

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.……     

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.     

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.     

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.……     

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.