牙科贵金属铸造合金

介绍了牙科贵金属铸造合金的国内外应用状况、基本要求和国际上的有关标准,以及高金合金,低金合金和银合金的主要成分、性能和作用,并简要介绍了国外最近对某些非贵金属合金生物相容性的比较趋于一致的评价。     

Surface analysis of nickel-chromium dental alloys

In this study, the surface compositions of four commercially available nickel-chromium alloys, Neptune, Rexalloy, Regalloy T, and Vera Bond, were compared and correlated to the alloys' corrosion behavior. The alloys were chosen to be representative of alloys with acceptable and unacceptable Cr levels, with and without Be additions. The results showed that the non-Be-containing alloys exhibited a homogeneous Cr-Mo oxide surface which resulted in more corrosion resistant alloys. The Be-containing alloys were shown to have non-uniform oxide surfaces. Areas on the surfaces of these alloys were low in Cr and O and enriched in Be. The oxide surfaces of these alloys were more easily disrupted and provided little resistance to accelerated corrosion processes. Thus, it was found that not only were the Cr and Mo content of the alloys important for corrosion resistance, but the composition of the surface oxide as well.     

Tin-based reactive solders for ceramic/metal joints

Contact angle measurements on silicon-nitride substrates were conducted on tin-based alloys, containing titanium and zirconium, to determine the suitability of these alloys as filler metals for low-temperature joining of ceramics. Titanium-containing alloys exhibited excellent wettability characterized by contact angles less than 20 deg, whereas the Zr-containing alloys exhibited contact angles around 50 deg. The superior wettability of the Sn−Ti alloys is attributed to the higher activity coefficient of Ti in Sn−Ti alloys. The liquidus temperature of the Sn−Ti alloys is in the 400°C to 600°C range. Hence, these alloys are expected to reduce the residual stress problem.     

铝钪合金的现状与展望

概述了钪对铝合金性能的影响,并对铝钪合金发展的历史和现状进行了概括。论述了铝钪合金的制备方法及铝钪合金的性质,如高强度、热稳定性高,焊接性、耐腐蚀性优良等。介绍了几种常用的铝钪合金,评述了铝钪合金的发展前景并指出了我国铝钪合金的研究方向。     

我国独具特色的稀土电工铝和铝稀土合金

中国稀土铝导体和铝稀土合金研究，开发和应用过程概况，稀土导电铝和稀土铝合金的特性；铝稀土合金应用领域逐步扩大，稀土消费量迅速增加；制取铝稀土合金系列的新思想和新工艺过程；稀土添加剂在铝和铝合金中的作用；某些值得注意的问题。     

Creep and tensile properties of several oxide dispersion strengthened nickel base alloys

The room temperature and 1365 K tensile properties and 1365 K tensile creep properties at low strain rates were measured for several oxide dispersion strengthened (ODS) alloys. The alloys examined included ODS Ni, ODS Ni-20Cr and ODS Ni-16Cr-4J5Al. Metallography of creep tested, large grain size ODS alloys indicated that creep of these alloys is an inhomogeneous process. All alloys appear to possess a threshold stress for creep. It is believed that the threshold stress is associated with diffusional creep in the large grain size ODS alloys and normal dislocation motion in perfect single crystalline ODS alloys. Threshold stresses for large grain size ODS Ni-20Cr and Ni-16Cr-4J5A1 type alloys are dependent on the grain aspect ratio. Because of the deleterious effect of prior creep on room temperature mechanical properties of large grain size ODS alloys, it is speculated that the threshold stress may be the design-limiting creep strength property.     

钼顶头破坏行为及强韧化分析

通过对钼顶头破坏行为的分析，说明了钼顶头破坏的主要原因。并进一步通过对钼顶头强韧化的分析，阐述了钼顶头延长使用寿命的措施，并制定了钼顶头生产工艺。     

Si-Al合金电子封装材料性能及显微组织研究

采用热压烧结法制备了70%Si-Al和90%Si-Al两种合金,测量了两种合金的典型热性能和力学性能,并观察和对比了两种合金的显微组织。结果表明:随着Si含量从70%升高到90%,在各测量温度下,合金材料的线膨胀系数都降低。热压烧结制备的材料Si相细小,致密度高,界面结合力好,热导率高。随着Si相含量的增加,热压的Si-Al合金热导率逐渐降低。烧结的Si-Al合金的抗弯强度和弹性模量随Si相含量的增加逐渐降低,材料的断裂主要以Si相的脆性断裂为主。     

Magnetic Entropy Change of （Gd1-xREx）5Si4（RE = Dy, Ho） Alloys

Magnetic Entropy Change of (Gd_(1-x)RE_x)_5Si_4(RE=Dy, Ho) Alloys     

A comparative study on mechanical properties of ultrafine-grained Al 6061 and Al 6063 alloys processed by cryorolling

The present work has been focused to investigate the mechanical behavior and microstructural characteristics of cryorolled Al 6063 and Al 6061 alloys. Hardness and tensile tests of the cryorolled Al alloys were carried out to understand its deformation behavior. SEM/EBSD was used to characterise the microstructures of cryorolled Al alloys and observed the formation of ultrafine-grained microstructures in the materials due to severe plastic strain induced during cryorolling. XRD was used to analyse the formation of different phases during cryorolling of the Al alloys. It is evident from the present study that UFG Al alloys exhibit higher hardness and strength when compared to the bulk Al alloys due to the grain size, higher dislocation density and precipitation hardening effect. The cryorolled Al 6061 alloys exhibit higher tensile strength (346 MPa) and hardness (120 H_v) as compared to Al 6063 alloys (Tensile strength: 240MPa and Hardness: 96.5 H_v) in the present investigation. The deformation mechanisms of UFG Al alloys contributing to their enhanced strength are discussed.     

铝、镁、钛合金材料在汽车工业中的应用和发展

阐述了现代汽车为节能、环保而开始大量采用铝、镁、钛舍金材料；介绍了铝、镁、钛舍金材料的性质特点，采用铝、镁、钛合金材料制造的汽车部件；并指出铝、镁、钛材料在汽车工业中的应用和发展前景。     

Corrosion fatigue of die-cast and extruded magnesium alloys

To study the fatigue life of die-cast and extruded AZ91D, AM50 and AZ31 magnesium alloys, corrosion fatigue tests were carried out using a rotating beam type fatigue machine. Corrosive environment (3.5% NaCl) significantly decreases fatigue life of alloys, especially for extruded alloys. The fatigue data at high stresses were analyzed using fitting equations. Extruded alloys show a higher sensitivity to the action of NaCl solution in comparison with die-cast alloys; however, their corrosion fatigue life is longer than that of die-cast alloys. Corrosion fatigue behavior of Mg alloys correlates with their mechanochemical behavior. The latter was studied by the polarization measurements of the dissolution rate of strained alloys. TEM observations confirmed that the maximums on the curves of Mg dissolution rate dependence on the strain in NaCl solution appeared at the work-hardening stages due to the creation and destruction of dislocation pile-ups.     

铁基阻尼合金的研究现状及发展趋势

铁基阻尼合金具有良好的阻尼性能、力学性能和加工性能,在船舶减振降噪中可发挥重要作用。对铁磁类、层错类、复相类铁基阻尼合金的阻尼性能和力学性能进行了介绍,分析了3类铁基阻尼合金的阻尼机理,并对铁基阻尼合金的发展趋势,尤其在舰船方向的应用进行了展望。     

贮氢合金进展

对贮氢合金的工作原理及应用,贮氢合金的基本类型及开发历史和发展趋势进行了综合评述。MmNi5系稀土合金和Laves相合金的开发应用已较为成熟,但其贮氢密度不高,高容量型的钒固溶体型合金和镁基合金是贮氢合金发展的新趋势。目前主要通过添加合金元素、开发制备工艺,改进微观相组织结构并兼以适当的表面处理,以提高钒固溶体型合金和镁基合金常温常压下的吸放氢特性及活化性能。     

钼-铼-镧合金微观组织及力学性能研究

通过固-液掺杂法在Mo-Re合金中加入稀土La₂O₃纳米颗粒制备得到Mo-Re-La合金, 将Mo-Re-La合金与Mo-Re合金、纯Mo的微观组织及力学性能进行对比研究, 得到如下结论: 在纯Mo中添加低含量Re元素(质量分数3.5%) 对Mo-Re合金有明显的细晶强化效果; 将La₂O₃纳米颗粒加入Mo-Re合金进一步细化和强化了Mo-Re-La合金。     

Strip Casting of High Performance Structural Alloys

There exists a great need for the development of high performance alloys due to increasing demands for energy conservation and environmental protection. Application of strip casting shows a strong potential for the improvement of properties of existing alloys and also for the development of novel alloy systems with superior properties. The present paper reviews our Center's activities in the development of high performance alloys by strip casting. Examples include (1) Al alloys, (2) wrought Mg alloys, and (3) bulk metallic glass (BMG) alloys.     

钼合金粉末冶金研究进展

钼及其合金具有优异的高温力学性能,被广泛应用于冶金、机械、化工、航空和核工业等领域。粉末冶金是钼合金的主要制备方法。通过固溶强化、第二相强化、细晶强化等多种强化手段可以提高钼合金的力学性能,从而拓宽钼合金的应用范围。本文介绍了粉末冶金制备钼合金的研究进展,包括粉体制备方法、压制工艺及坯体烧结工艺等,讨论了钼合金的强韧化方法及其机理,并展望了粉末冶金法制备钼合金的发展方向,以期对钼合金的设计和制备提供一些思路。     

Grain refining mechanisms in magnesium alloys — An overview

The literature on mechanisms of grain refinement in magnesium alloys is reviewed with regard to two broad groups of alloys: aluminium-bearing and aluminium-free alloys. While a low level zirconium addition significantly reduces the grain size of the aluminium-free alloys, the understanding of mechanisms of grain refinement in aluminium-bearing alloys is poor and in some cases probably confusing due to the interaction between impurity elements and aluminium in affecting the potency of nucleant particles. Mechanisms of grain refinement in magnesium alloys are dealt based on the experimental results in conjunction with microstructural observations. Informations revealed by this approach identify new directions for further research to focus on obtaining an improved understanding of the detailed mechanisms of grain refinement in magnesium alloys.     

钛及钛合金人体植入材料研究进展

钛及其合金因其具有低密度、高比强度、低弹性模量、良好的生物相容性和耐蚀性等特点, 被认为是一种理想的人体植入金属材料, 广泛应用于骨关节替换、牙齿修复等方面, 且对其的需求量快速增长; 同时, 钛也存在骨整合率低、抗菌性差、耐磨性差等缺陷, 急需进一步研究和改进。本文介绍了钛及钛合金作为人体植入材料的优异特性, 概述了国内外关于新型β型钛合金、表面改性钛合金、多孔钛合金、钛-陶复合材料的研究进展, 总结了钛及钛合金材料存在的一些问题, 为新型钛及钛合金材料的设计研发, 钛及钛合金综合性能的优化, 钛及钛合金使用寿命的延长提供参考。     

含Fe低CoAB5型贮氢合金的性能与结构

得到综合电性能良好的低CoAB5型贮氢合金成分。本文对所设计的一系列含Fe低CoAB5型贮氢合金MmNi3．55Co0.75-xMn0.4Al0.3Fex（x=0，0.1，0.2，0.3，0.4，0.5）进行了相关性能与结构测试，同时分析了对低CoMmB5合金结构参数与电性能之间的关系进行详细分析与表征。