材料期刊网

LASTER SURFACE CLADDING BY Co BASE ALLOY WITH Ce ON 20 # STEEL PERFORMANCE AND MICROSTURCTURE STUDYS

L.J.Shang1 2) , Y.Wang2) , Q.K.Cai1)and C.S.Liu1) 1) Northeastern University , Shenyang 110006 , China 2) Shenyang University , Shenyang 110044 , China

金属学报(英文版)

Onthebase of 20 # steel, Co base alloy with Ce and without Ce was obtained with laser heatingtechnology. Theresultshowsthat Cehasobviouslyeffecton alloy microstructureespe ciallyimprovethecorrosion resistancein acid by31 % ,oxygenation resistanceby23 % ,in al kalescent liquid by 23 % . Improve fearlessness 30% and improve hardness by 168 HV.Throughcontrast and analysison the Co base microstructure with Ce and without Ce . The paper discussthetheory of Ce modification Co base alloy from theside of cooling thermody namicsand dynamics

关键词: rareearth , null , null , null

H_2气氛保护热处理1J50组织结构与性能的研究

孙建春 , 盛光敏 , 陈登明 , 周安若 , 朱光俊

功能材料

1J50软磁合金的性能主要是通过H_2热处理获得的,在1130℃和H2气氛保护下对冷轧态1J50软磁合金进行了热处理.运用MATS-2010SA软磁测试仪对处理前后1J50软磁合金的磁性能进行了检测,运用金相显微镜、XRD等手段对处理前后1J50软磁合金的组织结构进行了分析.结果表明,通过H_2热处理,1J50软磁合金的矫顽力显著降低,起始磁导率和最大磁导率提高;组织结构发生明显变化,冷轧态1J50软磁合金组织为孪晶奥氏体,平均晶粒尺寸为200μm,处理过后,晶粒显著长大,平均晶粒尺寸为100μm;由于在600℃时采取了快冷,处理后1J50软磁合金中未出现大量FeNi相和FeNi_3相.

关键词: H2热处理 , 1J50 , 组织结构 , 性能

J(τ_0γ_0/(x_1x_2))行列式与弹塑性J积分不守恒的理论与实验证明

刘叔仪

金属学报

<正> 作为固体脆性断裂判据的J积分,其数值与其积分路径无关,这在文献中叫“守恒性”。这个守恒性已被推广到塑性断裂,这到底有否根据?本文目的是作这个问题的证明。未用原作者的方法,但由两个旋度判据得到应力应变函数行列式给出的一些否定结论,希望这对J积分应用条件的了解有所助益。1.弹塑性J积分守恒的条件 J积分

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Synthesis and Characterization of Some Transition Metal Chelates of 5-(1-Hydroxy-6-Naphthylazo-3-Sodium Sulphonate) Thiobarbituric (L1) and Barbituric (L2) Acids

Nabil S. Youssef , K.H.Hegab

材料科学技术（英文）

Some transition metal chelates of two ligands L1 and L2 were prepared and characterized by elemental analysis. The IR and 1H NMR spectra of several chelates of two ligands L1 and L2 showed the involvement of the azo group in chelation with the transition metal ions, in most of the studied chelates, and that the two ligands L1 and L2 showed the involvement of the azo group in chelation with the transition metal ions, in most of the studied chelates, and that the two ligands L1 and L2 were coordinated either in the enol or the keto form. IR spetra also showed that Fe(III)-, Ni(II)-, Mn(II)-, VO(II)-L1 and Cu(II)-L2 chelates behaved in a bidentate manner, in contrast with the two (1:1) M:L cobalt chelates with the two ligands are tridentate. TG analysis indicated the presence of three to twelve water molecules of hydration eliminated on heating up to 150°C and one or two coordinated water molecules removed at 150-180°C. The octahedral structure is proposed for all the chelates, except Cu(II)-L2 and Ni(II)-L1 chelates which have square planar geometry, based on their electronic spectra.

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Deformation and Dislocation Structure in L1_2 Titanium Trialuminide Alloys

Gengxiang HU , Shipu CHEN , Xiaohua WU , Yonghua RONG and Xiaofu CHEN(Dept. of Materials Science , Shanghai Jiao Tong University , Shanghai , 200030 , China)

材料科学技术（英文）

The deformation behaviour and the nature of dislocations of the Al3Ti-base L12 alloya modified with Fe and Mn etc, were investigated. The results show that the deformation and fracture character istics are closely related to the alloy compositions. The effect of hot-working process on the room tem perature ductility is remarkable, not only resulting in an appreciable improvement of compressive properties but also showing a 0.28% plastic strain in tensile test. The SISF dissociation of a < 110>dislocations on {111} planes was found at room temperature. The determined dissociation scheme is consistent with the mechanical behaviour of these alloys in the lower temperature region.

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L1(2)- and L1(0)-like cation-ordered structures in ZrO2-Y2O3 ceramics

Journal of Materials Research

Y0.25Zr0.75O2-x and Y0.5Zr0.5O2-y phases, with L1(2-) and L1(0-) like cation-ordered structures, respectively, have been found in ZrO2-Y2O3 ceramics in both the sintered and annealed states. High-resolution electron microscopy, energy-dispersive x-ray spectroscopy and computer simulation have been used to reveal the presence of the phases. The formation of Y0.25Zr0.75O2-x, and Y0.5Zr0.5O2-y phases was initiated during the sintering procedure and developed with the increase in annealing temperature and time. Segregation of yttrium, which was prevalent in different regions even within one grain, induced the formation of Y0.25Zr0.75O2-x and Y0.5Zr0.5O2-y phases.

关键词: yttria-stabilized zirconia;percent y2o3 alloy;x-ray-diffraction;solid-solutions;electron-diffraction;neutron-diffraction;modulated;structure;diffuse-scattering;average structure;tetragonal phase

Relationship between bonding characteristics and mechanical properties of L1(2) intermetallics

Journal of Alloys and Compounds

The bonding characteristics of A(3)B L1(2) intermetallics have been studied by the discrete variational X(alpha) cluster method. Two concepts, i.e. similarity of bonding strength and delocalization of bonding electrons, are introduced to explain the ductility or brittleness of the materials. The analysis of bonding characteristics shows that the strength of the A-A bond is similar to that of the A-B bond in A(3)B L1(2) intermetallics, and the delocalized degree of bonding electrons is different between the ductile and brittle intermetallics. This is a dominant factor in governing the ductile/brittle behavior of the materials. Environmental embrittlement in some intermetallics is related to the reactive centers in grain boundaries, which is due to the directional bonding and a small amount of charge transfer, and the reactive centers weaken the ability against the attack of the environmental species. The effect of stoichiometry on ductility contributes to the degree of delocalized bonding electrons. Mechanical strength of the materials is correlated with the covalent bond strength.

关键词: intermetallics;mechanical properties;bond strength calculations;intergranular hydrogen embrittlement;grain-boundary strength;ll2;ordered alloys;environmental embrittlement;fracture;ductility;co3ti

应力对1J79软磁合金强场磁导率的影响

尔延徽 , 毛昌辉 , 杨志民 , 杜军

稀有金属 doi:10.3969/j.issn.0258-7076.2008.01.009

采用8232型B-H交流回线仪对受力前后的1J79软磁合金在不同场强和频率下磁导率的变化进行了研究,采用XRD材料受力前后微观结构变化进行了分析.研究表明:(1)场强在l～10A·m-1范围内,直流条件下受应力lJ79合金的相对磁导率远低于不受应力lJ79合金的相对磁导率.(2)场强在1～10 A·m-1范围内,交流条件(5-30 kHz)下受应力lJ79合金的相对磁导率低于不受应力lJ79合金的相对磁导率,但低于直流条件下的降低幅度.(3)lJ79合金受力后,使有利于磁性能(111)晶面取向大大减少,是合金受力后相对磁导率下降的主要原因.

关键词: 应力 , 强场 , LJ79软磁合金 , 相对磁导率

使用安捷伦J&W DB-35ms超高惰性色谱柱和DB-XLB色谱柱对水中低于μg·L-1级的有机氯农药和除草剂进行GC/μECD法分析

Doris Smith , Ken Lynam

环境化学

本文中使用安捷伦SPEC C18AR固相萃取膜盘成功萃取了水中的有机氯农药残留和除草剂.使用双柱配置的GC/μECD系统进行检测,安捷伦J&W DB-35ms UI超高惰性色谱柱作为分析柱,DB-XLB色谱柱为确认柱.该方法为浓度接近或低于最大污染限值的含氯有机物提供了高度灵敏的分析方法.根据预估的分析物萃取浓度,方法使用的校准范围为1-100 ng· mL-1.分别对0.01 μg·L-1的加标水样和一个自来水水样进行了萃取和分析,结果证明可满足水中的有机氯农药残留和除草剂的测定.

关键词: 有机氯农药 , 除草剂 , 色谱柱

HARDENING OF L1_2-ORDERED Co_3Ti BY PRECIPITATION OF FCC-Co PHASE

W. H. Tian , S.L. Hu and M. Nemoto(Department of Materials Physics , University of Science and Technology Beijing , Beijing 100083 , China)(Department of Materials Forming , University of Science and Technology Beijing , Beijing 100083 , China)(Department of Materials Science and Engineering , Faculty of Engineering , Kyushu University , Fukuoka 812 , Japan)

金属学报(英文版)

The Co3 Ti phase hardens appreciably by the fine precipitation of disordered fcc Co-rich phase upon aging after quenching from solution annealing temperature. Transmission electron microscope (TEM)observations revealed that the precipitates are platelet in shape, lying nearly parallel to the {100} planes of the L12-ordered matrix, and perfectly coherent with the matrix lattice at the beginning of aging. The high temperature strength increases appreciably with the fine precipitation of disondered Co-rich phase over the whole temperature range investigated. TEM observations of the deformed alloys after underaging revealed that saperdislocations are pinned by precipitates indicating an attractive interaction between dislocations and precipitates.

关键词: Co_3 Ti , null , null , null , null