材料期刊网

INTERLAYER COUPLING AND FERROMAGNETIC RESONANCE IN Fe-Si/Cr MULTILAYERS

S.S.Yan: YH Liu: X.D Ma , YM. Zhang and L.M Mei(Department of physics , shandong University , Jinan 250100 , ChinaManuscript received 4 October 1995)

金属学报(英文版)

Fe-Si/Cr multilayers with amorphous Fe-Si magnetic layers and Cr nonmagnetic layers were prepared by an rf-sputtering method.When the thickness of the Cr layers varies from 0.5 to 6 nm, the interlayer coupling oscillates periodically from ferromagnetic to antiferromagnetism. For each sample only one wide uniform resonance peak is detected by the ferromagnetic resonance. The uniform resonance field Hb and the resonance line width △H_b oscillate periodically as the thickness of the Cr layers increases, which is related to the oscillation of the interlayer coupling from ferromagnetic to antiferromagnetism.The oscillation period is about 1.5nm.

关键词: :multilayer;interlayer coupling ;ferromagnetic resonance

CORRELATION BETWEEN STRESS COMPONENTS AND STRESS CORROSION CRACKS IN BRASS Lecturer,Department of Materials Physics,University of Science and Technology Beijing,Beijing 100083,China

QIAO Lijie LIU Rui XIAO Jimei University of Science and Technology Beijing , Beijing , China

金属学报(英文版)

The effects of stress components on nucleation sites and propagation directions of stress cor- rosion cracks in brass were investigated with specimens under mode Ⅱ and mode Ⅲ loadings. The results indicated that under mode Ⅱ loading,stress corrosion cracks nucleated on the site with maximum normal stress component and propagated along the plane perpendieular to the maximum normal stress,under mode Ⅲ loading,the stress corrosion crack was not evident on the 45°plane due to the general corrosion in aqueous solution with high NH_4OH concentra- tion,while stress corroded in aqueous solution with low NH_4OH concentration, numerous cracks with spacings of 10—150μm were found on the 45°plane with maximum normal stress and no stress corrosion cracks was observed on the plane with maximum shear stress.

关键词: stress corrosion cracking , null , null , null

FeMoB Enhanced Sintering of P/M 316L Stainless Steel

YANG Xia , GUO Shiju

钢铁研究学报(英文版)

Liquidphase enhanced sintering of powder metallurgy (P/M) 316L stainless steel by addition of sintering aids was studied. 2%-8% of prealloyed FeMoB powder with two different particle sizes was added as sintering aids, and the specimens were sintered in vacuum at 1 200-1 350 ℃. The results show that the fine FeMoB powder (5-10 μm) has stronger activated effect. The sintered density increases with the increase in sintering aid content or sintering temperature. Warm compaction has a better effect on the control of dimensional precision of compacts. The prealloyed FeMoB powder deviated from Mo2FeB2 component can also be sintering aid of P/M 316L stainless steel.

关键词: P/M 316L stainless steel;liquidphase sintering;activated sintering;FeMoB;sintering aid

试棒的w_0/l_0值对Zn-5%Al合金超塑性m-δ关系的影响

刘勤 , 裔式珙

材料研究学报

在250℃以■=0.025min~(-1)测到的Zn-5%Al 合金的超塑性m-δ曲线均属式。w_0/l_0值加大使m_0,m_L 和δ_F 值增大,但对δ_L 和m_F 值无大影响。试样厚度的加大(由1增大到2mm)仅使δ_L 和δ_F 值增大,考虑w_0/l_0比值的影响,C_3~((m_0-m_L))-(m_L=m_(mas))型C.L.m-δ方程式规划为:或其中,m′_0(W_0/l_0)=m_0,m′_0>m_0;m′_L(w_0/l_0)=m_L,m′_L>m。w_0/l_0=0.15—0.39。当w_O/l_0=1时,缺口效应消失,δ(或δ_F)值为最大。

关键词: Zn-5%Al合金 , mechanics of superplasticity , C.L.m-δequation

Ion sputter erosion in metallic glass-A response to "Comment on: Homogeneity of Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass" by L-Y. Chen, Y-W. Zeng, Q-P. Cao, B-J. Park, Y-M. Chen, K. Hono, U. Vainio, Z-L. Zhang, U. Kaiser, X-D. Wang, and J-Z Jiang J. Mater. Res. 24, 3116 (2009)

Journal of Materials Research

The morphology of the dark and bright regions observed by transmission electron microscopy for the Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass strongly depends on the ion beam parameters used for ion milling. This indicates that the ion beam could introduce surface fluctuation to metallic glasses during ion milling.

关键词: room-temperature

Jian ZHANG/Langhong Lou

材料科学技术（英文）

关键词:

Ni64Al21V15沉淀过程DO22向L10(M=1)结构转变的微观相场模拟

常秀丽 , 王永欣 , 陈铮 , 张静 , 程立维

稀有金属材料与工程

基于微观相场模型,研究了Ni64Al21V15合金在1150 K时效过程中相结构演化.结合微观组织演化图像和各个格点上原子占位几率的演化,分析了DO22结构向L10 (M=1)结构转变机制.合金沉淀中期,在相界处析出L10(M=1)结构.研究发现,L10 (M=1)结构形成可分为3类:在DO22与L12相界处形核,沿[001]方向排列,向DO22相扩张;在DO22结构90°有序畴界处形核,沿[001]方向排列,向DO22扩张;在2个[100]向排列的DO22结构交界处形核,沿[100]方向排列,向DO22结构扩张.DO22相中,V主要占据β位,Ni主要占据α2和α3位,Al主要占据α1位;随后,V向α2位跃迁,在(002)面富聚且发生有序化,逐渐占据β和α2位,Ni原子发生面间跃迁,由α2位跃迁至α1位,逐渐占据α1和α3位,Al原子向相外扩散.DO22结构最终转变为高度有序的L10(M=1)结构.

关键词: 结构转变 , L10(M=1)结构 , 序参数 , Ni-Al-V合金 , 微观相场

异材焊接件A508/52M/316L在高温水环境中的应力腐蚀破裂

李光福李冠军方可伟彭君杨武张茂龙孙志远

金属学报 doi:10.3724/SP.J.1037.2011.00316

采用慢应变速率实验(SSRT)方法, 研究了先进的异材焊接件A508/52M/316L在模拟压水堆一回路290 ℃高温水环境中的应力腐蚀破裂(SCC)特性. 实验在-780 mV至+200 mV范围的电位下进行, 模拟一回路水化学从低O含H的理想低电位状态到溶解O$_{2}$明显超标的高电位状态的服役环境. 该焊接件显微组织和化学成分分布较复杂, 显著的变化发生在A508/52M和52M/316L 2个界面附近. 在SSRT拉伸试样的典型位置处加工了同样尺寸的尖锐缺口, 以模拟应力集中和加速实验, 并比较这些典型位置的SCC 敏感性. 结果表明, 当电位位于-780 mV至-300 mV范围时, SSRT试样总是以韧性断裂形式在镍基合金焊缝中部发生断裂. 当电位升到-200 mV至+200 mV范围时, 试样发生显著的SCC脆断, A508/52M界面区周围是该焊接件最脆弱的部位, 在该界面和附近的A508热影响区发生穿晶应力腐蚀破裂(TGSCC), 在紧邻界面的镍基合金焊缝薄层发生沿晶应力腐蚀破裂(IGSCC). 讨论了破裂机理和实验结果的工程意义.

关键词: 压水堆核电站 , primary water , dissimilar metal weld , stress corrosion cracking , electrode potential , water chemistry

异材焊接件A508/52M/316L在高温水环境中的应力腐蚀破裂

李光福 , 李冠军 , 方可伟 , 彭君 , 杨武 , 张茂龙 , 孙志远

金属学报 doi:10.3724/SP.J.1037.2011.00316

采用慢应变速率实验(SSRT)方法,研究了先进的异材焊接件A508/52M/316L在模拟H压水堆一回路290℃高温水环境中的应力腐蚀破裂(SCC)特性.实验在-780 mV至+200 mV范围的电位下进行,模拟一回路水化学从低O含H的理想低电位状态到溶解O2明显超标的高电位状态的服役环境.该焊接件显微组织和化学成分分布较复杂,显著的变化发生在A508/52M和52M/316L 2个界面附近.在SSRT拉伸试样的典型位置处加工了同样尺寸的尖锐缺口,以模拟应力集中和加速实验,并比较这些典型位置的SCC敏感性.结果表明,当电位位于-780mV至-300mV范围时,SSRT试样总是以韧性断裂形式在镍基合金焊缝中部发生断裂.当电位升到-200mV至+200 mV范围时,试样发生显著的SCC脆断,A508/52M界面区周围是该焊接件最脆弱的部位,在该界面和附近的A508热影响区发生穿晶应力腐蚀破裂(TGSCC),在紧邻界面的镍基合金焊缝薄层发生沿晶应力腐蚀破裂(IGSCC).讨论了破裂机理和实验结果的工程意义.

关键词: 压水堆核电站 , 一回路水环境 , 异材焊接件 , 应力腐蚀破裂 , 电位 , 水化学

CURRENT STATUS OF HIGH-RESOLUTION ELECTRON-MICROSCOPY AND ITS APPLICATIONS TO MATERIALS SCIENCE AND CONDENSED MATTER PHYSICS

材料科学技术（英文）

The present paper summarizes the current status of high resolution elect;on microscopy ( HREM) and the applications of HREM to materials science and condensed matter physics. This review recounts the latest development of high resolution electron microscope, progress of HREM and the applications of HREM, including the crystal structure determination of microcrystalline materials and characterization of the local structure of the defects and nanostructured materials as well as qualitative and quantitative analysis of the grain boundaries, interfaces and interfacial reactions in the advanced materials by means of HREM in combination with electron diffraction, subnanometer level analysis, image simulation and image processing.

关键词: juxtaposed pentagonal antiprisms;two-dimensional quasicrystal;domain;boundary structures;close-packed phases;nanocrystalline materials;crystal-structure;copper oxidation;initial-stage;translational;symmetry;rotational symmetry