A356合金的低周疲劳行为及塑性应变能

采用电解低钛铝合金、工业纯铝与Al-10Ti中间合金,制备了具有不同钛含量的电解加钛A356合金(EA356合金)和熔配加钛A356合金(MA356合金),研究了加钛方式和钛含量对A356合金的应变能密度和低周疲劳性能的影响。结果表明:4种合金均表现为明显的循环硬化行为;具有较高钛含量的E14、M14合金的循环硬化能力高于低钛含量的E10和M10合金;合金的塑性应变能密度受应变幅的影响且具有循环相关性;高应变幅时,塑性应变能较高但随循环周次变化较小;当应变幅较低时,合金的塑性应变能较小但变化较大,特别是塑性较好的E10和M10合金;无论是电解加钛还是熔配加钛,钛含量为0.1%的E10和M10合金的的塑性应变能密度和疲劳寿命均优于钛含量为0.14%的E14和M14合金;合金的疲劳寿命对加钛方式不敏感,在相同钛含量下,两种加钛方式的合金具有相近的低周疲劳寿命。     

加钛方式与钛含量对A356合金组织和性能的影响

研究了不同钛含量的电解A356合金的组织和力学性能,并与相应钛含量的熔配加钛A356合金进行了比较.结果表明:随着钛含量的增加,二者的晶粒和一次枝晶都明显细化,硅颗粒尺寸、纵横比均有所降低,硅颗粒圆形度有所增加,意味着硅颗粒形状得到改善.但当钛含量大于0.1%时,这种影响变弱.钛含量和加钛方式对合金的屈服强度和抗拉强度影响不大且二者相当,但塑性随着钛含量的增加而增加,当钛含量达到0.1%时,两种合金均具有最佳的塑性和质量系数.对具有相同钛含量的合金,电解加钛A356合金的晶粒和Si颗粒的尺寸小于相应钛含量熔配加钛A356合金,硅颗粒圆形度也优于相应熔配加钛A356合金,电解A356合金的塑性、质量系数均优于相应钛含量的熔配加钛A356合金,但加钛方式对硅颗粒纵横比影响不系统.     

Structure and properties of alloys of the Mg-REM system

The structure and properties of magnesium alloys alloyed with rare-earth metals (REM) are considered. The alloys are compared to commercial magnesium alloys. Perspectives of magnesium alloys with earlier unused REM are discussed.     

Properties and applications of some gold alloys modified by rare earth additions

The influence of rare earth (RE) additions on the microstructure and some properties of gold and gold alloys have been studied. RE additions can refine the grain size of gold alloys, but show a tendency to segregation, both dendritic segregation in cast alloys and grain boundary segregation in annealed alloys. For gold alloys, RE additions are generally used in trace amounts or dilute concentrations in order to avoid a large segregation of RE and the potential embrittlement of gold alloys. The experimental results demonstrate that RE additions can inhibit recovery softening, increase the recrystallization temperature and enhance the strength of gold alloys. The strengthening mechanisms of RE additions in gold alloys are discussed. Some gold alloys with RE additions have been developed and their applications are illustrated briefly     

Microstructure and mechanical properties of NbZrTi and NbHfZrTi alloys

Two medium-entropy alloys,NbZrTi and NbHfZrTi,were prepared by arc melting.Both NbZrTi and NbHfZrTi alloys are composed of simple body-centered cubic(bcc)solid solution phase and exhibit dendritic structure.After being homogenized,both NbZrTi and NbHfZrTi alloys are still composed of the single bcc solid solution phase,but the microstructure of the two alloys transforms from the dendritic structure into the polycrystalline structure.Two alloys display significantly workhardening effect during compression at room temperature and show relatively good deformation plasticity during compressive deformation at room temperature.For NbZrTi and NbHfZrTi alloys,the dynamic recrystallized grains form along the boundary during compression at the temperatures of 1073 and 1273 K.     

Al-Mg合金的组织及力学性能

测试了不同成分的Al-Mg的力学性能,并分析了其显微组织。结果表明,增加Mg含量可以提高合金的强度及塑性,对合金的显微组织影响不大。     

西北有色金属研究院研制的部分钛合金及产业化

西北有色金属研究院是我国重要的钛合金研究与开发的单位之一，近40年来，一直致力于钛合金的研究、开发及产业化，仿制与创新研制出近60种钛合金，一些仿制的钛合金已大批量生产，获得成功的应用，如纯Ti、TC4、半TC4、Ti．Pd、Ti．Mo．Ni、BT20、BT16、HT7M等等；一些创新研制的钛合金也已获得成功的应用和批量生产，如TC21、Ti75、Ti31、CT20、Ti12LC等等，为我国钛合金的发展做出了突出贡献。本文简要综述了西北有色金属研究院仿制与创新研制的部分钛合金及其产业化。     

Welding of unique and advanced alloys for space and high-temperature applications: welding and weldability of iridium and platinum alloys†

In the last five decades, significant advances have been made in developing alloys for space power systems for spacecraft that travel long distances to various planets. The spacecraft are powered by radioisotope thermoelectric generators (RTGs). The fuel element in RTGs is plutonia. For safety and containment of the radioactive fuel element, the heat source is encapsulated in iridium or platinum alloys. Ir and Pt alloys are the alloys of choice for encapsulating radioisotope fuel pellets. Ir and Pt alloys were chosen because of their high-temperature properties and compatibility with the oxide fuel element and the graphite impact shells. This review addresses the alloy design and welding and weldability of Ir and Pt alloys for use in RTGs.     

Y, Nb对快速凝固TiAl合金组织和性能的影响

研究了元素Y和Nb对用熔体快淬法制备的TiAl基快速凝固合金组织及性能的影响。发现添加Y的快速凝固TiAl合金主要为等轴晶,主要组成相为α2和少量的γ相。随着Y含量的增加,γ相的含量增加,快速凝固TiAl合金的组织逐渐细化。不同Nb含量的快速凝固TiAl合金的组织为块状结构和层片状结构,主要由γ和α2两相组成,层片间距显著细化,为15～17nm。快速凝固TiAl合金的硬度比其铸态合金显著提高。     

铝合金在运输机上的应用与发展

铝合金是民航客机和军用运输机的最主要的机体结构材料。通过对一些典型运输机用铝合金情况的分析，综述了运输机用铝合金的发展思路和重点。最后指出，高性能铝合金的研制和生产是保证我国大型运输机研制的重要基础之一。     

The corrosion and oxidation resistance of iron- and aluminium-based powder metallurgical alloys

The corrosion performance of both iron- and aluminium-based powder metals is reviewed and compared, where possible, to similar conventional alloys. Iron-based alloys produced from consolidated powder or compacted amorphous chips have generally been found to have improved corrosion resistance compared to their wrought counterparts, whereas sintered iron-based alloys generally exhibit poorer corrosion resistance. The corrosion performance of aluminium-based alloys produced from consolidated powder is frequently better than that of their conventional counterparts. Aluminium alloys are considered in four groups: AlZnMgCu, AlMg, AlLi and AlCu alloys. The current understanding of the corrosion behaviour of powder metals is assessed and suggestions are made for future investigations.     

快淬工艺对La-Mg-Ni系贮氢合金微观结构及电化学性能的影响

用铸造及快淬工艺制备了La-Mg-Ni系（PuNi3型）贮氢合金La2Mg（Ni0．85Co0.15）9Bx（x=0，0．1，0．2），分析测试了铸态及快淬态合金的微观结构与电化学性能，研究了硼及快淬工艺对合金微观结构及电化学性能的影响。结果表明，铸态合金具有多相结构，主相包括（La，Mg）Ni3相（PuNi3型）和LaNi5相，残余相为一定量的LaNi2相和微量的Ni2B相，经快淬处理后Ni2B相消失，并且其它相的相对量随淬速的变化而变化。不含硼合金的容量随淬速的增加而单调减小，含硼合金的容量随淬速变化有一个极大值。合金的循环寿命随淬速的增加而增加，铸态及快淬态合金均有优良的活化性能。     

医用可降解镁合金抗菌性、溶血以及生物相容性的研究进展

镁及镁合金因其密度低、弹性模量与硬组织匹配、可降解吸收以及具有优异的生物相容性等优点已成为可降解生物材料领域的研究热点。但镁合金体内降解速率过快且降解时产生析氢反应并引发局部pH环境升高,这会影响周围组织的生长,甚至会发生溶血、溶骨现象,这严重限制其在临床上应用。采用添加适当合金元素以及镁合金表面改性被认为是减缓镁合金腐蚀速率以期达到其降解行为可控的有效方法。综述了可降解镁合金抗菌性和溶血性能的研究状况,系统阐述了近5年来可降解镁合金生物相容性的最新进展,展望了医用可降解镁合金未来的研究方向和挑战。     

喷射成形高硅铝合金及其在导电材料方面的应用

本文介绍了喷射成形技术的特点及在高硅铝合金中的应用潜力,综述了喷射成形制备高硅铝合金的制取方法及研究现状,扼要地总结了喷射成形高硅铝合金在导电材料方面的应用,最后提出了这一研究领域中存在的问题及发展前景。     

Microstructure and corrosion resistance of alloys of the Mg-Zn-Ag system

New alloys of the Mg-Zn-Ag system are studied. The capacity for precipitation hardening and mechanical properties of extruded Mg-Zn alloys are determined depending on the degree of their alloying with silver. The microstructure of the alloys is studied with the help of light and electron microscopes; the grain sizes are measured before and after the extrusion. The hardness and the mechanical properties of extruded alloys are determined after single and double aging.     

铝锂合金组织、性能及成形工艺的研究现状与展望

铝锂合金具有较高的比强度、比刚度以及优良的抗腐蚀性能和抗疲劳性能,在航空、航天、航海等关键领域备受关注.铝锂合金在美、俄等国已经被研究并应用了数十年,我国也通过多个科技攻关项目,在铝锂合金的研发、生产与应用方面取得了长足进展,但与发达国家相比尚有一定差距.本文从国内外铝锂合金的发展历程出发,深入探讨了铝锂合金的合金化思...     

细晶超塑性变形及其在镁合金中的研究现状

介绍了镁合金作为结构件的优越性及其应用受到限制的原因；描述了超塑性变形的特征、研究方向及超塑性变形的模型；综述了细晶对超塑性的影响，镁合金中的细化晶粒工艺，镁合金的塑性变形机制及细晶镁合金的超塑性变形机制。指出如果超塑性成形能够在镁合金中得到成功的应用，则可大大拓宽镁合金的实际应用领域。     

钛合金在航天飞行器上的应用和发展

主要介绍了高强韧钛合金、高温钛合金、低温钛合金和铸造钛合金及钛合金的先进成形技术在航天色行器上的应用,指出了钛合金发展现状和趋势。其中对粉末冶金技术和超塑成形／扩散连接（SPF／DB）技术做了较详细的介绍。重点介绍了美国和俄罗斯的粉末冶金技术发展现状和我国粉末钛合金技术在多种型号产品研制中的应用情况。同时指出超塑成形／扩散连接新技术为克服钛合金成形昂贵又难以加工而受到限制的问题提供了新途径。     

钯基非晶合金的制备和应用综述

非晶合金由于其独特的组织结构,在力学、化学和物理方面都有着特殊的性能。结合非晶合金的发展历程,介绍了非晶合金制备方法,对其性能及应用领域进行综述介绍。介绍了钯基非晶合金在催化、磁学和精密制造等领域的应用前景,总结了常见块体钯基非晶合金的制备方法,对钯基非晶合金的制备技术发展和潜在应用前景进行了展望。     

镁合金抗氧化及合金化阻燃研究进展

综述了镁合金氧化燃烧及燃点的测定方法、镁合金抗氧化和阻燃机理及合金元素(Ca，Be，RE，Y)对镁合金阻燃性能影响的研究现状。介绍了抗氧化和阻燃镁合金研制进展及应用现状，指出了研究中存在的问题及发展方向。