过饱和ZA27的尺寸收缩及其与组织转变的关系

研究了过饱和ＺＡ２７的尺寸变化规律及其与组织转变的关系。过饱和ＺＡ２７在８０℃时效过程中发生迅速而明显的尺寸收缩现象，其收缩率高达０．３０％左右，随后尺寸变化很小。铜加剧尺寸收缩。η相（锌相）和ε相（ＣｕＺｎ４）从过饱和固溶体中迅速脱溶是造成尺寸收缩的原因。     

热处理对ZA27合金组织和性能的影响(英文)

采用X射线衍射(XRD)、扫描电镜(SEM)及力学性能表征等手段,研究热处理对ZA27合金组织和性能的影响。结果表明,合金的铸态组织主要由α、β、η和ε相组成。经365℃固溶处理1h后,α和η相消失,组织主要由过饱和β相组成。过饱和固溶体的分解分为两个阶段;在时效初期,过饱和β相发生分解;随着时效时间的延长,ε相发生四相反应:α+ε→T′+η。通过适当的热处理工艺,ZA27合金可以获得理想的伸长率和强度匹配。     

Ce对ZA43合金组织和性能的影响

研究了Ｃｅ对高铝锌合金（ＺＡ４３）组织性能及淬火－时效过程的影响。确认加Ｃｅ处理后，ＺＡ４３合金中含有Ｃｅ化合物的存在，并分析测定了含Ｃｅ化合物的化学成分。在此基础上提出了Ｃｅ细化ＺＡ４３合金α相机理：加Ｃｅ后成分过冷效应所引起的枝晶分枝熔断脱落对细化α相起主要作用。     

Ce对Zn-Al合金组织性能的影响

研究了Ｃｅ对ＺｎＡｌ合金（ＺＡ２７、ＺＡ４３）的力学性能、淬火时效特性及耐磨性的影响。结果表明，Ｃｅ能明显细化合金的铸态组织，提高其强度和塑性。当ＺＡ２７和ＺＡ４３中含Ｃｅ量分别为０．１０％和０．１５％时，获得最佳的力学性能。提出了Ｃｅ细化ＺｎＡｌ合金的机理，加Ｃｅ后成分过冷效应所引起的枝晶熔断脱落对细化α相起主要作用。     

喷雾沉积高硅ZA27合金的组织与性能

报道喷雾沉积高硅ＺＡ２７合金的组织和高温性能，采用环缝式雾化器，氮气雾化，钢基底水平单向运动，合金成分为标准ＺＡ２７中添加４％Ｓｉ和０．３％Ｆｅ，喷雾沉积组织由孔洞（２－４％）富硅相（３９－４０％）和基体构成，富硅相呈球状弥散均匀分布，时效之前，喷雾沉积与常规铸造高硅ＺＡ２７合金的显微硬度和高温（１５０℃）硬度没有明显差别，长期时效之后，喷雾沉积合金的上述性能明显高于常规铸造合金，喷雾沉积与合金化     

Ce,La对高阻尼Zn—22%Al合金阻尼稳定性的影响

采用自然时效、人工时效等热处理工艺,借助航向电镜和室温低频扭摆内耗仪,研究了微量Ｃｅ,Ｌａ对高阻尼Ｚｎ－２２％Ａｌ合金时效后显微组织和阻尼性能（内耗）的影响。结果表明,经水淬后８０℃温轧的Ｚｎ－２２％Ａｌ合金在低于温轧温度下时效时,其阻尼性能 量Ｃｅ,Ｌａ的加入,提高了经水淬后８０℃温轧的Ｚｎ－２２％Ａｌ合金的阻尼性能,减缓了经１５０℃时效后阻尼性能的降低。     

喷雾沉积Ce变质高硅ZA27合金组织与性能

研究了０５％Ｃｅ变质前后喷雾沉积高硅ＺＡ２７合金的组织与力学性能。喷雾沉积高硅ＺＡ２７合金的组织由富Ｓｉ相、光滑无特征区、细层片状共析体、粗层片状共析体所组成；加０５％Ｃｅ变质后，组织结构大大细化，主要由富Ａｌ、Ｃｅ亮点状相、富Ｓｉ、Ｃｅ多角形相以及细层片状共析体组成；显微硬度测量结果表明，Ｃｅ变质提高了材料的塑性，从而有利于高硅ＺＡ２７合金的推广应用。     

Mg,Cu及时效对ZA27合金组织和腐蚀特性的影响

研究合金元素Ｍｇ和Ｃｕ及时效处理时间及ＺＡ２７合金的组织和腐蚀特性的影响。研究发现，元素Ｍｇ，Ｃｕ和时效处理对合金的组织转变有大影响，Ｍｇ抑制α和β相的固相转变，而Ｃｕ促进α和β相的固态转变，从而影响合金的腐蚀特性。根据盐雾腐蚀试验结果结合组织特征得出：ＺＡ２７合金中Ｍｇ和Ｃｕ的合适加入量分别为０．０３％－０．２０％Ｍｇ，０．５％－２．５％Ｃｕ，最佳时效处理时间为２ｈ适宜。     

铝、铜、镁对铸态锌基合金组织和阻尼性能的影响

研究了铝、铜、镁等合金化元素对铸态锌基合金组织和室温下阻尼性能的影响， 利用悬臂梁法测试了合金的阻尼性能。结果表明， 锌铝二元合金随铝含量增加， 初生α相增多， 共晶体逐渐减少直至消失。镁、铜等合金元素对Ｚｎ２７ ％ Ａｌ 合金α相的大小和分布无大的影响。镁、铜可固溶于基体中， 当其含量较高时， 分别在组织中形成ＭｇＺｎ２ 化合物和ＣｕＺｎ５ 化合物， 分布于晶界。铝含量在６ ％ ～６０ ％ 范围内的锌铝合金在铸态下均具有高的阻尼能力； 铜、镁等合金化元素的加入降低了Ｚｎ２７ ％ Ａｌ合金的阻尼性能。ＺｎＡｌ 系合金的高的阻尼性能是在外部的交变应力作用下， 晶界和相界间的粘滞性滑动以及α相发生局部的微塑性变形， 使振动能量得以消耗而造成的     

90 ℃时效对固溶态ZA27合金组织与性能的影响

对ZA27合金进行365℃/3 h的固溶化处理,研究90℃时效对其拉伸性能及阻尼性能的影响。结果表明,固溶态ZA27合金经过90℃、6 h时效后的组织主要由α相和η相层片组织组成,另有少量粒状组织。固溶态合金的拉伸强度和阻尼性能均较低,伸长率较高。时效使合金拉伸强度和阻尼性能先提高后下降;使延伸率先降低后提高。时效6 h后ZA27合金的拉伸强度为401 MPa,伸长率为6.6%,阻尼性能为3.0×10^-3。     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

Effect of Short-Time Aging on the Pitting Corrosion Behavior of a Novel Lean Duplex Stainless Steel 2002

The effect of short-time aging in the temperature range between 400 and 1000 °C on the pitting corrosion behavior and mechanical property of a novel lean duplex stainless steel(LDSS) 2002 was investigated through the potentiostatic critical pitting temperature(CPT) tests and the Charpy impact tests. Both the pitting corrosion resistance and the toughness of aged specimens degraded due to the precipitation of detrimental secondary phases and the most significant reduction of CPT and impact energy emerged at 650 °C concurrently. The CPT of LDSS 2002 specimen aged at 650 °C decreased by 28 °C, and the impact energy dropped from 69 to 29 J/cm~2 compared with the solution-annealed sample. Transmission electron microscopy characterization showed that the main precipitates in LDSS 2002 were Cr_2N and M_(23)C_6 along the ferrite–austenite grain boundaries.     

INTRODUCTION TO PATENTS

The invention provides a method of making a mold which can reduce SOx generation rate while preventing decrease in hardening rate in the case of using sulfuric acid for a hardener composition. The method has a mixture step in which fire-resistant particles, a hardener composition and a binder composition are mixed to obtain a composition for a mold. The hardener composition contains sulfuric acid. In the mixture step, sodium carbonate is added. A molar ratio of the sulfuric acid to the sodium carbonate is 0.5 or more and 4.0 or less.     

China Foundry Week 2014

China Foundry Week, hosted by the Foundry Institution of Chinese Mechanical Engineering Society （FICMES） each year, is a large academic event in China. It is one of the ten high-impact activities sponsored by the Chinese Mechanical Engineering Society.     

17th Conference of Hydrodynamic and Electromechanical Control Engineering Call for papers

正1.Contents In order to promote the academic exchanges and technical communication of the research in the field of fluid power transmission and control,fluid control engineering specialized committee of the Chinese Society of Theoretical and Applied Mechanics will hold the 17th Conference of Hydrodynamic and Electromechanical Control Engineering on July 27-29,2014 in Tibet,Lhasa city.     

Information for Contributors

正The Transactions of Nonferrous Metals Society of China,founded in 1991 and sponsored by The Nonferrous Metals Society of China,is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology,including mineral processing,extraction metallurgy,metallic materials and heat treatments,metal working,physical metallurgy,powder metallurgy,with the emphasis     

Preface

<正>We are pleased to present this Special Issue of Transactions of Nonferrous Metals Society of China containing selected papers from the First Asian Conference on Aluminum Alloys(ACAA-2013),held in Beijing,China,13–17 October 2013.This conference has been initiated,with approval of     

Information for Contributors

The Transactions of Nonferrous Metals Society of China, founded in 1991 and sponsored by The Nonferrous Metals Society of China, is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology, including mineral processing, extraction metallurgy, metallic materials and heat treatments, metal working, physical metallurgy, powder metallurgy, with the emphasis on fundamental science. It is the unique preeminent publication in English for scientists, engineers, under/post-graduates on the field of nonferrous metals industry. This journal is covered by many famous abstract/index systems and databases such as SCI Expanded, Ei Compendex Plus, 1NSPEC, CA, METADEX, AJ and JICST.     

Formulas of Tension of Continuous Rolling Process

The development of computer controlled continuous rolling process calls for a mathematical expression that can express the inequality condition of "constant flow". Tension is the link of the continuous rolling process. From the condition of dynamic equilibrium, a differential equation of tension is given out. On the basis of the physical rules established from the industrial practice and experimental studies, the law of volume constancy, the linear relation of forward slip and tension, the state equation of continuous rolling, the formula of dynamic tension, and the formula of static tension have been obtained. These formulae reflect the functional relations between tensions, thickness, roll velocity, and time in the continuous rolling process. It is implied that the continuous rolling process is a gradually steady, controllable, and measurable dynamic system. An assumption of predicting the thickness of a steel plate using these tension formulae is also put forward.     

A Concordant Shift Model for Flow in Bulk Metallic Glasses

The homogeneous plastic flow in bulk metallic glasses(BMGs) must be elucidated by an appropriate atomistic mechanism. It is proposed that a so-called concordant shifting model, based on rearrangements of five-atom subclusters,can describe the plastic strain behaviour of BMGs in a temperature range from room temperature to the supercooled liquid region. To confirm the effectiveness of the atomic concordant shifting model, a comparative investigation between the vacancy/atom model and the concordant shifting model is carried out based on the estimation of the strain rate deduced from two models. Our findings suggest that the atomic concordant shifting model rather than the vacancy/atom exchange model can well predict the large strain rate in the superplasticity of BMGs.