镁阳极氧化膜微观结构和防护性能的比较

借助SEM(扫描电子显微镜)、盐雾试验等技术，对以不同阳极氧化工艺在镁合金AZ91D表面所得膜层的微观结构及其综合防护性能(包括耐蚀性、耐磨性及结合力)进行了比较研究.结果发现，不同工艺条件下形成的阳极氧化膜在微观结构及性能上存在显著差异.环保型阳极氧化新工艺所得膜层的综合防护性能优于经典工艺，对基体金属能提供更为有效的保护.      

镁阳极氧化表面改性不同工艺及其成膜效果的比较

阳极氧化是Mg表面处理方法中最有效因而最常用的一种技术。对Mg阳极氧化经典工艺HAE和Dow17以及绿色环保工艺Starter进行全方位比较，发现工艺条件的选择对阳极氧化成膜效果有着十分重要的影响。Mg阳极氧化成膜条件具有多样性，但工艺条件不同，不仅阳极氧化成膜现象不同，而且所得膜层的颜色、均匀性、粗糙度及其耐蚀性、耐磨性和与基体金属之间的结合力等性能指标也不相同。     

有色金属表面微弧氧化技术评述

微弧氧化是一项在有色金属表面原位生长陶瓷膜的新技术。本文介绍了Ａｌ、Ｍｇ、Ｔｉ金属表面微弧化技术的发展历史及氧化物陶瓷膜生长的原理,并比较微弧氧化和阳极氧化技术的工艺及性能特点,显示微弧氧化工艺比阳极氧化简单,氧化膜的综合性能比阳极氧化膜高得多,是一项广阔应用前景的新技术。     

微弧氧化技术与材料表面陶瓷化

介绍了一种在非铁合金表面原位生长陶瓷层的新技术,比较了微弧氧化与阳极氧化的工艺特点及膜层性能,综合分析了微弧氧化的国内外研究状况及应用前景。     

载银抗菌功能膜的制备和研究

介绍了1种制备新型载银抗菌功能膜的方法。首先制备阳极氧化初级膜，然后通过特殊的着色工艺把银添加到氧化膜中，最终获得了金黄色和棕色的抗菌膜。以大肠杆菌和金黄色葡萄球菌为实验菌种，采取体外实验的方法，测试了试样的抗菌效果。通过实验发现，新制备的抗菌膜和在空气中存放24个月的抗菌膜，都具有良好的抗菌效果，而且所制备的抗菌膜具有好的颜色稳定性。对抗菌膜进行了扫描电镜、X射线光电子谱和俄歇电子谱的研究与分析，发现抗菌膜中存在多种以银元素的化合物。通过1个对比实验，计算了抗菌膜中的银量和银离子在不同介质中的释放速度。研究表明，这种工艺制备的抗菌膜具有可靠和高效的抗菌效果。     

铝合金复合钎焊材氧化膜厚度的检测和改进

铝合金复合钎焊材表面自然吸附氧化膜会对铝热交换器钎焊造成不良影响。使用X射线光电子能谱仪(XPS)对比分析了不同条件下的铝材氧化膜厚度和表面镁含量的变化情况，确定了合适的氧化膜检测方法和退火工艺。结果表明，氮气保护并直接出炉冷却的退火工艺，能减少氧化膜厚度并降低生产成本。     

有色金属表面微弧氧化技术

微弧氧化工艺比阳极氧化简单,氧化膜的综合性能比阳极氧化膜高得多,是一项有广阔前景的新技术。微弧氧化技术的主要研究单位列于下表。     

铝合金型材阳极氧化膜的滴碱与落砂试验

通过试验，研究了合金成分、常温封孔、阳极氧化工艺条件对氧化膜耐蚀性，耐磨性的影响；讨论了这些因素对氧化膜耐蚀性、耐磨性的影响机理，指出了为保证氧化膜的耐蚀性、耐磨性而采取的工艺措施。     

铝合金两种阳极氧化工艺的氧化膜性能对比

为了探讨铝合金阳极氧化配方对氧化膜层性能的影响,研究比较了硫酸-硼酸和硫酸两种阳极氧化工艺所得氧化膜层的性能。通过金相显微镜、扫描电子显微镜(SEM)和显微硬度仪观察分析了膜层表面的均匀性、封闭工艺后氧化膜的表面形貌和膜层的维氏硬度;同时,采用点滴法和动电位法研究了氧化膜在NaC l溶液中的耐腐蚀性能。结果表明,在一定条件下,经硫酸-硼酸阳极氧化所得的膜层较硫酸阳极氧化膜的平整、致密、均匀,其耐蚀性也优于硫酸阳极氧化膜的。     

基于人工神经网络的铝铜合金硬质阳极氧化工艺优化

目的探究Al-5%Cu合金硬质阳极氧化处理的最佳工艺。方法采用硬质阳极氧化试验装置对Al-5%Cu合金进行硬质阳极氧化处理,并用扫描电镜和显微硬度计研究了在硫酸电解液中生成的硬质阳极氧化膜的微观组织结构、厚度及硬度。综合采用正交试验以及人工神经网络的方法,设计了三因素三水平的实验方案,研究了硫酸溶液温度、电流密度和阳极氧化时间对硬质阳极氧化膜的硬度及膜层厚度的影响。利用人工神经网络系统对Al-5%Cu合金阳极氧化的工艺参数进行了优化。结果采用硬质阳极氧化技术可以增加Al-5%Cu合金的表面硬度。制备的氧化膜厚度较均匀,表面质量较好,硬度较高。硫酸溶液的温度是影响表面氧化膜层微观组织及硬度的主要因素。结论 Al-5%Cu合金进行硬质阳极氧化的最佳工艺条件范围为:氧化液温度-9~-7℃,电流密度4~4.8 A/dm2,氧化时间115~120 min。     

Development of a new lean lubrication system for near dry machining process

The minimal quantity of lubricant supply (MQL) technique has been applied to environment friendly machining processes. However, in the MQL technique, a large volume of oil mist is discharged to the environment. In this paper, a new lean lubrication system for a near dry machining process called “direct oil drop supply system (DOS)” is proposed. The performance of the DOS technique was evaluated by the milling processes. The DOS technique can supply a very small oil drop directly to the cutting edge without making oil mist, and the DOS shows almost same machining performances compared to the MQL technique.     

镁合金零件表面化学改性技术

研究了镁合金表面化学改性的几种表面处理工艺,讨论了镁合金非铬酸盐处理的工艺过程、操作条件.测定、分析了膜层的厚度、表面形貌和膜层成分,对比了几种不同处理工艺的实验结果.结果表明,在优化非铬酸盐处理工艺条件下,所得的膜层细致均匀且与基体的结合力良好,对镁合金基体有较好的保护作用,膜的防腐能力与铬酸盐转化膜的防腐能力相当.     

多点压板成形技术及其板料冲压成形工艺

板料在冲压成形过程中常出现起皱现象,这是板料受压失稳的结果。论文提出一种新型的多点压板成形冲压技术,板料在冲压成形过程中,板料的上、下面受弹性压板力的约束,从而可以提升板料的失稳临界应力,减少板料的受压屈曲与起皱。同时研制一种可重构的杆系柔性成形模具,实施多点压板成形冲压工艺。试验表明,这种新型模具可以实施快速重构,同时可以有效地控制板料的起皱,特别适用于中小批量曲面板件的冲压成形加工。     

WC-based cermet coatings produced by cold gas dynamic and pulsed gas dynamic spraying processes

Due to their mechanical properties, WC-based cermet coatings are extensively used in wear-resistant applications. These coatings are usually produced using thermal spray processes. However, due to the nature and the environment of these spraying processes, the feedstock powder structure and properties suffer from decomposition, which subsequently degrade the performance of the coatings produced. The cold gas dynamic spraying process appears to be a promising alternative technique to preserve the properties of the feedstock powder during the coating preparation. Although the latter technique can minimize or eliminate the degradation of the sprayed material, the deposition of cermet using this technique is a difficult task. In this study, two types of cermet powders, the nanocrystalline (WC-15Co) and the conventional (WC-10Co4Cr) powders were deposited using the cold gas dynamic spraying and the pulsed gas dynamic spraying processes. The feedstock powders and coatings microstructures were investigated by OM, SEM and XRD, as well as their hardness. The results revealed the possibility of depositing cermet coatings onto aluminum substrates using both processes without any degradation of the carbide phase of the feedstock powder. The cold gas dynamic spraying process experienced difficulty in depositing and building up dense coatings without major defects. The pulsed gas dynamic process produced thick cermet (conventional and nanocrystalline) coatings with low porosity as long as the feedstock powder was preheated above 573 K.     

Application of statistical filtering technique to single and double electron beam textured surfaces

The texturing of steel surfaces is well known to affect their functional performance. Different processes (e.g. forming, painting) are affected by different wavelengths of surface structures which, in order to study the phenomena, are usually separated through filtering processes. New texturing processes call for new filtering techniques, and amongst the latest ones, the Gram-Schmidt (GS) decomposition technique proved to be suitable for deterministic patterns such as Electron-Beam Textured (EBT) surfaces.Optimisation lead to new textures, with more dense patterns, so extending the GS methodology seemed natural and meaningful. This paper describes how the technique was algorithmically adapted and how it will benefit process control.     

板料成形中有限元模拟技术的应用

使用传统的靠经验和反复修模试模的方法研发模具，不仅难以掌握板料成形的真实过程，而且会造成人、财、物、时的浪费。将有限元技术引入冲压成形模拟中是解决这一问题行之有效的方法，对板料冲压成形模拟进行了讨论，并重点介绍了Dynaform软件的应用。     

Contribution to the elucidation of corrosion initiation through confocal laser scanning microscopy (CLSM)

In this work, an electrochemical minicell has been developed to study the microscopic changes that occur on the electrode surface at the first steps of the corrosion process by means of optical and confocal laser scanning microscopy. Duplex stainless steel (UNS 1.4462) specimens (1.6 mm in diameter) have been used to check this technique. It has been observed that the corrosion process happens in a sequential way: first, a pit appears on the tested surface; later, the corrosion product spreads and catalyzes new corrosion processes. The spread corrosion product grows in a three-dimensional way. The used technique has demonstrated to be very useful for the observation of the initiation of corrosion processes.     

Thermal spraying I: Powder consolidation—From coating to forming

Thermal spray is a microsolidification consolidation process for metals, intermetallics, ceramics, polymers, and composites. Thermal-spray processing has become an important powder-consolidation technique, and innovations are now yielding novel ways of manufacturing new materials and material combinations. This article, the first of two parts, reviews thermal-spray processes, describes their characteristics, and describes the attributes of the materials sprayed by such processes. Part I presents the range of thermal-spray processes and the materials systems that are able to be produced, leading from a coating to a forming technology.     

Methods for producing high-purity calcium

The techniques used in the United States for producing calcium metal are described. The methods and attempts to produce high-purity calcium from the crude calcium prepared by the current processes are discussed. A vaporization technique for the distillation of crude calcium is described in detail, and a fractional distillation technique for preparing special high-purity calcium is reported.     

铸造过程数值模拟中的后处理显示

后处理显示是铸造过程数值模拟的一个重要组成部分，它能把通过数值模拟得到了的抽象的三维目标数据以图形的方式直观的表示出来，文中在介绍了基于网格的后处理显示的几项技术的基础上，提出了一种新的技术，它通过铸件的STL文件来显示铸件的外轮廓，通过图形合成技术来生成总体的显示效果，与基于网格的后处理显示技术相比，消除了以网格单元棱边来表示外轮廓所产生的锯齿现象及轮廓线过多的现象，从而提高了显示的质量。