Al效应对LaNi5-xAlx系合金贮氢性能的影响

测定了LaNi5-xAlx(x=0，0．1，0．2，0．3)系合金在吸放氢过程中的贮氢性能。结果表明，贮氢容量随合金中Al含量的增加而降低，平台压力和热力学焓变和熵变随合金中Al含量的增加而降低，合金形成氢化物的稳定性增强；LaNi5-xAlx系合金在吸放氢过程中的平台压力存在一定的差异，即滞后现象，滞后系数随合金中Al含量的增加而降低，这是LaNi5-xAlx系的晶胞体积随合金中Al含量的增加而增加的必然结果;LaNi5-xAlx系合金的吸放氢动力学参数也与合金中的Al含量有关，活化能随Al含量的增加而降低，但活化能不存在数量级的差异。     

镶牙换代钛金牙

分别以Miedema坐标、合金自扩散激活能ΔHs与形成焓ΔHf为参数坐标，将多元合金分解为若干相应的二元合金叠加，对有实验结果的128个二元和153个多元机械合金化(MA)非晶合金的形成规律进行了研究。结果：以上2种坐标中，分别可由一直线或曲线将非晶形成与非形成区分割，方程为：Miedema坐标，二元系，y=2．8600x 0．22；多元系，y=2．7900x 0．27，总区分率均为80％：ΔHs～ΔHf坐标，二元系，y=0．0005x^2 0．20x-23；多元系，y=0．0005x^ 0．21x-25，总区分率分别为85％和83％。合金包含过渡族金属、涵盖非过渡族金属及类金属，并扩展至多元系，同时与已有定性以及半定量结果进行了比较。     

非化学计量比混合稀土—镍系贮氢合金的研究

本文研究了非化学计量比混合稀土－镍系贮氢合金ＭｍＢｘ的配比数ｘ对合金结构、热力学性能和金属氢化物（ＭＨ）电极充放电发性能的影响。随着配比数ｘ的减小,合金晶胞体积和金属氢化物生成焓（－ΔＨ）增加,平台压力降低且与配比ｘ有ｌｎｐｅｑ＝１．９９ｘ－１１．１３的关系。当ｘ〈５．０时,合金在ＣａＣｕ５型主相之外析出Ｃｅ２Ｎｉ７第二相,该第二相具有较高的电催化活性。ｘ〈５．０时,合金电极具有较高的初容量和活化     

Al—Si系合金（3）

3.3 Al-Si-Mg系合金的组织与机械性能此系中JIS实用合金有AC4A、AC4C和AC4CH。它们都是铸造性能良好的Al-Si合金中添加了少量的Mg,由于Mg_2Si中间相析出的热处理效果提高了强度。Mg量略微多一点的AC4C具有高的强度、良好的铸造性和耐蚀性。为了防止Fe的坏影响,通常加入Fe量的50～80％的Mn。在此系合金中,多使用较纯的Al-Si-Mg系AC4C(AA356)和Fe含量控制在0.20％以下提高韧性的AC全CH(AAA356),但后者大量用作汽车轮子。在铸件用的合金中,它们虽属中等强度的,但延伸率高、韧性     

Al—Si系合金（4）

4 变形材料合金的组织与性能 Al-Si系变形铝合金的用途,主要是做锻件、接合件和建筑材料。本节叙述这些用途,以及说明合金的有关组织和性能; 4.1 锻造用合金表3示出按Si量和锻造温度区分的锻造合金及用途。多用于制造各种活塞、VTR缸等。过共晶系合金着重用于要求耐磨性     

Tb—Dy—Fe—M四元系超磁致伸缩材料的磁性

研究了Ｔｂ０．２７Ｄｙ０．７３Ｆｅｘ（ｘ＝１．８，１．９，２，２．１）三元系和Ｔｂ０．２７Ｄｙ０．７３Ｆｅ１．８Ｍ０．１（Ｍ＝Ｚｎ，Ｔｉ，Ａｌ，Ｃｒ）四元系超磁致伸缩材料的磁性。合金在氩气保护的真空电弧炉中熔炼，铸锭在１０００℃真空热处理７天，用法拉第磁秤测定居里温度，用ＬＤＪ９５００振动样品磁强计测磁化曲线，用电阻应变计测量磁致伸缩。Ｔｂ０．２７Ｄｙ０．７３Ｆｅｘ合金的居里温度在３５５～３７５℃范围内，加入Ｚｎ、Ｔｉ、Ａｌ和Ｃｒ降低合金的居里温度，加Ｃｒ增加合金的磁致伸缩，加Ａｌ增加合金在低磁场下的磁致伸缩，加Ｚｎ，Ｔｉ降低磁致伸缩。除加Ｃｒ外，热处理也能提高合金的磁致伸缩。     

TiC/Al和SiC/Al中间合金对Mg-Al系合金晶粒的细化

研制出两种新型的Mg-Al系合金晶粒细化剂——Al-4％TiC和Al-10％SiC中间合金。结果表明：这两种中间合金对Mg-Al系合金均有良好的晶粒细化作用。向AZ63合金中加入1％的TiC／Al中间合金可使其晶粒由原来的约2mm减小至250μm左右；向AZ31合金中加入0．5％的SiC／Al中间合金可使其晶粒由原来的约600μm减小至200μm左右。分析认为，表面覆有Al4C3过渡层的TiC和SiC颗粒可以作为α-Mg的结晶核心，同时SiC颗粒本身也可以作为α-Mg的异质结晶核心。大量异质结晶核心的存在是导致α-Mg晶粒细化的主要原因。     

钛系多元储氢合金的研究

本文对钛系多组元储氢合金进行了开发研究,发现Ti-Zr-Mn-V-Cr系具有满意的性能。该合金容易活化,吸放氢速度快,储氢量大,释氢量可达195ml/g以上。P-C-T曲线表明,该合金的平台特性好,平台压力适中,工作性能稳定,比现有Ti系典型合金TiFe优越。     

Zr－Nb系合金耐蚀性能研究

结合核动力堆用燃料包壳对锆合金耐蚀性能的要求，大范围考察了Ｎｂ含量为０．５％，１．０％，２．６％（ｗｔ％）的Ｚｒ—Ｎｂ二元合金及含Ｃｒ、Ｍｏ、Ｓｎ、Ｂｉ、Ｆｅ、Ｃｅ和Ｓｉ的Ｚｒ－１Ｎｂ及多元合金，共１７种成分的Ｚｒ－Ｎｂ系合金在４００℃，１０．３ＭＰａ水蒸汽中的长期腐蚀规律（达１８２天）。在腐蚀转折前，Ｚｒ－Ｎｂ系合金的腐蚀动力学曲线均近似于抛物线规律，而在转折之后存在与线性规律偏离现象。长期腐蚀增重的分析说明：通过合理的多元合金化，即增加或降低Ｎｂ含量，并主加Ｆｅ、Ｂｉ、Ｓｎ和Ｎｉ而辅加少量的Ｃｒ、Ｍｏ、Ｔｅ和Ｓｉ，Ｚｒ－１Ｎｂ合金的耐蚀性大有潜力可挖。     

球磨改性处理对Ti0．9Zr0．1Mn1．5合金相结构及储氢性能的影响

系统研究了Ti0．9Zr0．1Mn1．5储氢合金经不同时间（t=0min，10min，30min，60min）球磨改性处理后对其相结构及储氢性能的影响。结构分析表明，Ti0．9Zr0．1Mn1．5合金在球磨改性处理前后均由单一的六方结构的C14型Laves相组成；随着球磨时间的延长，合金粉的平均粒度减小，并出现了部分团聚现象。储氢性能测试表明，铸态合金经4次吸放氢循环后活化，室温最大吸氢量和有效放氢量分别为209．3ml／g和157．6ml／g，放氢率为75．3％；随着球磨时间的延长，合金的活化性能得到改善，室温最大吸氢量和有效放氢量均先升后降，且都在球磨30min时达到相应最高值231．4ml／g和203．8ml／g，放氢率达到88．1％。由此可见，适当的球磨改性处理能有效地改善Ti0．9Zr0．1Mn1．5合金的综合储氢性能。     

IFHTSE global 21: heat treatment and surface engineering in first decades of twenty-first century Part 5 – Modelling based design of surface engineered systems

Abstract

Aspects of surface engineering design, namely, simulation of processing and service behaviour and prediction of properties, are discussed and summarised. Available design techniques are demonstrated by means of examples. Two process simulation modelling approaches, relating to oxidation of Ti alloys and nitriding of steels, are described. A novel optimisation approach to extract Young's modulus, yield strength and work hardening exponent of a power law (load–displacement) material is presented. Design and service behaviour simulation case studies of surface engineered titanium alloy gears for the sports car industry are also presented. It is shown that advances in theoretical principles and computational methodologies and tools, together with the ever increasing abundance and accuracy of thermodynamics and kinetics databases of materials and processing atmospheres, have enhanced the reliability of surface engineering simulations to a level good enough for industrial application. Barriers and development trends in surface engineering design are also addressed.     

Properties of Mechanically Milled Nanocrystalline and Amorphous Mg–Y–Ni Electrode Alloys for Ni–MH Batteries

Nanocrystalline and amorphous Mg2Ni-type Mg20-xYxNi10(x = 0,1,2,3 and 4) electrode alloys were fabricated using mechanical milling.The effects of the Y content and milling time on the microstructures and electrochemical performances of the alloys were investigated in detail.X-ray diffraction and transmission electron microscopy analyses revealed that the substitution of Y for Mg yields an obvious change in the phase composition and micro morphology of the alloys.When the Y content x B 1,the substitution of Y for Mg does not change the major phase Mg2 Ni,but with a further increase in the Y content,the major phase of the alloys transforms into the YMg Ni4 YMg3 phase.A nanocrystalline and amorphous structure can be obtained by mechanical milling,and the amorphisation degree of the alloy visibly increases with increased milling time.Electrochemical measurements indicate that the discharge capacity of the alloys first increases and then decreases with increasing Y content and milling time.The substitution of Y for Mg dramatically ameliorates the cycle stability of the as-milled alloys,and the mechanical milling more or less impairs the cycle stability of the alloys.Furthermore,the high rate discharge ability,electrochemical impedance spectrum,Tafel polarisation curves and potential step measurements indicate that the electrochemical kinetic properties of the as-milled alloys first increase and then decrease with increasing Y content and milling time.     

铼元素分离富集研究进展

铼元素是一种可广泛应用于国防、航空航天以及新型科技领域的重要战略资源。铼元素在地壳中含量极低,是一种稀散金属,需要通过高效的分离富集才能获取。介绍近年来铼金属的冶炼/回收工艺流程及进展,综述近年来铼金属的冶炼/回收工艺流程及其进展,重点介绍可应用于铼富集分离的块体材料、纳米材料、生物质材料、介孔硅材料等新型吸附材料及其在铼一次资源与二次资源的开发与回收中的应用,并对铼富集与分离技术的发展进行展望。     

PMO-EMS组合调控提高铸坯均质化应用实践

脉冲磁致振荡(PMO)凝固均质化技术是通过促进形核并形成“结晶雨”细化凝固组织、提高铸坯均质化的一项原创技术。生产实践表明,该技术对提高连铸坯等轴晶率、降低偏析具有显著作用。将PMO与电磁搅拌(EMS)进行优化组合,利用EMS的搅拌作用,将PMO形成的“结晶雨”均匀分布于铸坯心部,消除等轴晶区偏心问题,从而大幅度提高铸坯组织对称性和均质化效果稳定性。结果表明,应用PMO-EMS组合调控技术可显著提高铸坯均质化水平,以轴承钢GCr15和齿轮钢20CrMnTi为例,等轴晶区对称性明显增加,偏析指数则可以分别控制在1.04和1.05以内。     

Progress in abrasive fluidized bed machining

The use of abrasive fluidized bed equipment in a broad range of manufacturing processes is reviewed. In particular, applications in deburring and finishing of complex-shaped metal components, in super-finishing of dies for injection molding, in cleaning and polishing of electronic devices, and in surface preparation of tungsten carbide milling tools are reviewed. Attention is focused on the effects of the most important process parameters, such as machining time, abrasive type and mesh size, and flow or jet speed. The extent of material removal and the change in surface roughness as a function of the process parameters are addressed. Selected numerical and analytical models that are useful for automation and control purposes are discussed. Finally, the industrial sustainability of the processes and equipment investigated is highlighted.     

静电喷雾制备功能化表面膜层的研究进展

静电喷雾是一种高效且应用广泛的膜层制备技术,能够使微细粒子均匀分布,在微纳米材料加工制备领域表现出巨大的潜力.介绍了静电喷雾技术在制备功能化表面膜层的最新研究进展,总结了静电喷雾技术的优缺点.在静电喷雾机理与装置方面,详细阐述了泰勒锥液滴、微细射流及破碎雾化过程,分析了膜层在喷雾中的生长过程以及累积之后的内部变化,论述了膜层相组成和晶体结构的控制方式,介绍了液滴的带电方式和有无静电场的区别,对比了静电喷雾的多种装置及喷嘴类型;在氧化物膜层方面,介绍了金属氧化物膜层、非金属氧化物膜层、金属颗粒掺杂氧化物膜层,以及复合膜层的成膜条件、膜层相组成和晶体结构.归纳了多种功能的静电喷雾聚合物膜层,分析了静电喷雾在钠离子电池、锂离子电池以及钙钛矿太阳能电池中的应用.描述了含碳、硅等非金属无机物膜层的研究现状,探讨了静电喷雾参数对膜层结构的影响,以及膜层结构和性能的关系,并概括了多种膜层的厚度变化.最后,展望了静电喷雾技术的应用前景及发展趋势.     

Critical review of electrochemical honing: sustainable and alternative gear finishing process. Part 2: effects of various process parameters on surface characteristics and material removal rate

Part 1 of this review discussed conventional gear surface finishing processes and their advantages and limitations, and introduced the electrochemical honing (ECH) process (and its extension of pulsed electrochemical honing (PECH)), to improve the surface characteristics of different types of gears, working principles, mechanism of material removal and equipment details. Part 2 gives a review of past work, and discusses effects of various process parameters on surface characteristics and finishing productivity (i.e. material removal rate), advantages and limitations, and its other applications. The objective of this review paper is to present ECH/PECH as one emerging alternative, economical, productive and sustainable gear finishing process.     

Electrolytic plasma processing for cleaning and metal-coating of steel surfaces

Electrolytic plasma processing (EPP) involves electrolysis and electrical discharge phenomena and it is an emerging, environmentally friendly surface engineering technology. Electrolytic-plasma/material surface interactions during processing can be used for cleaning of metal surfaces, formation of diffusion layers and/or deposition of metal, ceramic and composite coatings. The present work was concerned with cleaning and deposition of metal coatings on steel surfaces for corrosion protection. The effects of processing parameters on (i) cleaning steel surfaces (oxides and contamination); and (ii) Zn and Zn–Al coating deposition were investigated. Surface roughness and oxygen content prior to and after cleaning were evaluated by profilometry and energy dispersive X-ray analysis (EDAX), respectively. The structure of the EPP cleaned outer surface layer as it evolves after the electrolytic–plasma interaction was studied by high resolution TEM. Morphology, microstructure, composition, adhesion and density of EPP-deposited Zn and Zn–Al coatings on cleaned surfaces were studied as a function of processing parameters. Corrosion properties of the cleaned and coated steels were evaluated by corrosion potential and potentiodynamic polarization measurements. The results show that EPP can effectively produce clean surfaces and also metal and alloy coatings at high deposition rates, and it has a great potential as a new plasma surface engineering technique.     

Advanced characterisation of nanocomposite coatings

Nanocomposite coatings are systems comprised of two or more phases. Such multiphase coatings are becoming increasingly important as they offer the possibility of tailoring the coating architecture and achieving exciting new properties. An understanding of the coating nanostructure is important to complete the classic processing-structure-properties relationship and expedite the development of novel systems. However, comprehensive structural and chemical characterisation of such nanostructured coatings remains a considerable challenge. In this paper, results on three nanocomposite coating systems are presented (Ti-Al-B-N, Ti-B-C and Cr-Cu-N). The use of XRD, TEM and XPS for phase identification, determination of the relative phase fraction, grain size and structural defects are described. The accordance (or not) of the phase composition and relative phase fraction with the equilibrium phase diagram for these systems is examined. Specific interesting features of the spectra and micrographs are interpreted and their nanostructural significance are discussed. Correlations are made between the nanostructure and mechanical properties.     

基于DEFORM的冲头和刀口相对位置偏移量对模具及产品的影响

针对生产加工中出现的产品不良、冲头和刀口崩坏等现象,通过DEFORM仿真,分析了冲裁模具冲头与刀口的相对位置偏移量对模具和产品的影响,具体分析了模具冲头与刀口的相对位置偏移量对模具所受压力、冲头和刀口的疲劳强度、产品毛刺大小等几方面的严重危害,得出冲压模具冲头与刀口的相对位置偏移量对模具所受力的大小影响不大,但会降低冲头和刀口的疲劳强度、影响产品毛刺大小,降低产品生产效率和模具寿命,影响产品质量,并提出通过进行人工合模操作或通过使用合模机可以很好地改善冲头与刀口的相对位置偏移量,提高模具精度和产品质量。