医用钛合金超声-电化学抛光工艺

研究了一种对常用的医用钛合金(Ti-6Al-4V)试件进行表面光整加工的新工艺.在试验的基础上,将功率超声波与电化学作用相结合,利用功率超声波的能量特性并结合电化学抛光的特点,实现对常用钛合金试件的超声-电化学抛光处理.分析了功率超声波对电化学抛光过程的促进作用及电流密度对抛光效果的影响,获得了较为合理的工艺参数.结果表明,采用合理的超声-电化学抛光工艺参数,经2 min左右时间,试件表面粗糙度由 3.2 μm降至0.2 μm,这不仅可以改善试件的表面粗糙度,而且还可以增加表面氧化膜中钛的氧化物含量,进一步提高钛合金植入物的生物相容性和耐腐蚀性.     

磁流变抛光液的研制

磁流变抛光是近十年来新兴的一种先进光学制造技术。首先简要介绍了磁流变抛光的抛光机理，然后对在磁流变抛光中起重要作用的磁流变抛光液的组成，流变性和稳定性进行了研究。在外加磁场强度高于318kA/m时，磁流变抛光液的剪切应力大于20kPa，该应力足以完成磁流变抛光，最后给出一个磁流变抛光的实例，证明了磁流变抛光液的实用性，实验中磁流变抛光的最大材料去除率约为0.2μm/s.     

通用型功率超声发生器

笔者根据功率超声的共同特性和要求，研制出一种通用型功率超声发生器，可用于各种功率超声设备，如超声清洗，超声焊接，超声加工，超声乳化，分散等。     

国内铝制品无铬酸电化学抛光工艺开发现状

传统的铝制品酸性电化学抛光溶液含有严重污染环境的铬酸，综述了80年代以来，我国开发无铬酸电化学抛光工艺的现状和研究成果。     

铝硅合金压铸件电解抛光新工艺

简述了电解抛光原理，提出了一种铝硅合金压铸件的电解抛光新工艺。     

稀土金属抛光金刚石膜技术

研究开发了一种有效地抛光化学气相沉积金刚石厚膜的技术。该技术利用化学活性很强的稀土金属镧的金刚石的化学反应，在一定的工艺条件下可对金刚石膜进行有效的抛光。抛光绵高低与抛光温度有关，在温度大于９００℃时抛光效率较高，可达３４μ／ｈ，表面度可从原来的Ｒａ １２μｍ降至Ｒａ１．６μｍ，如用于后续的精抛光，可大大光的时间和提高抛光效率，使表面十分粗糙的金刚石厚膜的精抛光能得以经济地进行。     

铝合金电化学抛光工艺

采用综合评价方法研究了铝合金电化学抛光添加剂，结果发现，在碱性溶液中加入PEG作光亮剂可明显改善抛光效果，加入酒石酸钠等作稳定剂可延长溶液使用周期，并在此基础上优化了抛光工艺条件。试验表明，采用此工艺来抛光铝材获得的综合效果优于酸性电化学抛光和传统碱性电化学抛光，是一项有应用前景的新工艺。     

现场金相检测中电解抛光技术的应用探索

为了改善工件表面的抛光效果,解决传统机械抛光对抛光工件几何形状的限制,提高实际工程中对工件的抛光效率,本文介绍了一种全新的抛光工艺——电解抛光。电解抛光工艺与工件的材质、电流大小以及电解液的温度等参数密切相关,合理的控制这些工艺参数才能达到理想的抛光效果。本文主要探究电流密度、抛光温度以及阴阳极间的距离等因素对抛光效果的影响。     

我国功率超声技术近况与应用进展

文章综述了我国功率超声技术近10年发展状况，介绍了功率超声的超声空化机理、超声换能器、超声发生器等基础研究以及在超声清洗、超声焊接、超声处理、环保、声化学、超声治疗、超声马达等方面的新应用及其发展重点。     

等离子体加工光学元件装置技术研究

介绍了一种新型的超光滑表面加工技术-等离子体抛光.设计和安装了一套等离子体加工试验平台.加工试验平台由真空系统、等离子体源、射频电源系统、气路系统组成.试验平台具有独立变量气体流量、真空度、射频电源发射功率和反射功率和加工时间.对于石英玻璃材料的实验结果表明等离子体抛光是一种可行的有潜力的抛光技术.     

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.     

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.     

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 ...     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.