Y.M. Hao
金属学报(英文版)
An approximate calculation of the exchange interaction constant JRT between therore-earth sublattice and the transition metal sublattice in R2Fe17-xAlx (R=Tb, Gd,and Dy) compounds is given by the molecular-field model and the results of neutrondiffraction. The calculated values, -JR,T/k, for Dy2Fe17-xAlx (x=5, 6, 7 and 8),Tb2Fe10Al7, Gd2Fe17-xAlx (x=7, 8) compounds are 8.62K, 8.64K, 9.52K, 10.34Kand 10.66K, 10.65K, and 9.85K, respectively, they are in agreement with the ex-perimental values, -JR,T/k, of Dy2Fe17-xAlx (x=5, 6, 7 and 8), Tb2Fe10Al7 andGd2Fe17-xAlx (x=7, 8) compounds, which are 8.77K, 9.25K, 10.1K, 10.9K and10.35K, 10.1K, and 10.3K, respectively. The origins of the difference between thecalculated and the experimental results are discussed.
关键词:
neutron diffraction
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null
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null
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YANG Jilian ZHANC Baisheng DINC Yongfan China Institute of Atomic Engergy
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Beijing
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ChinaYANG Yingchang ZHANG Xiaodong Peking University
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Beijing
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ChinaPAN Shuming General Research Institute for Non-Ferrous Metals
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Beijing
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China associate professor
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P.O.Box 275
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Branch No.30
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Beijing 102413
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China
金属学报(英文版)
The N occupying sites and magnetic structures in R_2Fe_(17)N_x(R=Y,Dy,Nd)are de- termined by neutron diffraction.The effects of the site occupation of N on magnetic properties are discussed primarily.
关键词:
neutron diffraction
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null
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null
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null
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null
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null
YANG Jilian ZHANG Baisheng JIN Lan DING Yongfan YE Chuntang Institute of Atomic Energy
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Beijing
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ChinaYANG Yingchang SUN Hong KONG Linshu Peking University
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Beijing
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China YANG Jilian
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Associate Professor
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P.O.Box 275
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Sub 80
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Beijing 102413
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China
金属学报(英文版)
The site occupancies in permanent magnetic alloy Y_2(Fe_(0.95)Al_(0.05))_(14)B has been studied by means of neutron diffraction.The results from profile refinement show that Al enters the tetragonal structure of Nd_2Fe_(14)B and occupies the 4c and 8j_2 sites of the space group P4_2/mnm preferably.The relation between the site occupancies and the magnetic proper- ties is discussed preliminarily.
关键词:
Y_2(Fe_(0.95)Al_(0.05))_(14)B
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null
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null
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null
XIE Guoqiang
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YANG Jijian
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ZHANG Baisheng
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LI Wendan(China Institute of Atomic Energy
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Beijing) Manuscript received 13 December 1994
金属学报(英文版)
U—10wt%Zr alloy has been analysed by neutron diffraction method to determine the constituent phases and their crystal structures.The collected diffraction data are processed using Rietveld' s profile technique (with program“ Fullprof ”). Four phases,α-U,δ, γand α—Zr, in the alloy at room temperature and the corresponding volume fractions as well their structural parameters are obtained from the data analysis, For the δ-phase, a partially ordered unusual hexagonal structure of the modified C32(AlB2) type is confirmed.
关键词:
:U-10wt%Zr alloy
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null
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null
YANG Jilian ZHANG Baisheng JIN Lan DING Yongfan YE Chuntar Institute of Atomic Energy
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Beijing
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China YANG Yingchang
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KONG Linshu Associate Professor
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P.O.Box 275-80
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Beijing 102413
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China
金属学报(英文版)
Neutron diffraction measurements on Nd2(Fe0,Si0 ,)14B at room temperature and 77 K were performed. Data analysis using profile refinement was carried out. The results show that at room temperature Si atoms occupy preferentially 4c, 8j, and I6k2 sites, and the magnetic moments of bath Nd and Fe are parallel to C-axis. At 77 K, the site occupations remain unchanged as in room temperature, while the calculated Nd magnetic moment direction has an angular deviation of 37.8 ° from C-axis.
关键词:
neutron diffraction
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null
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null
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null
李眉娟
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刘晓龙
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刘蕴韬
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郑明毅
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王琛
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陈东风
金属学报
doi:10.11900/0412.1961.2015.00286
以商业纯Mg和AA1050 Al板材为初始材料, 采用累积叠轧技术在室温下进行不同轧制道次变形制备了Mg/Al多层复合板材料, 并对3 cyc轧制的Mg/Al多层复合板材料在200 ℃分别进行不同时间退火处理. 利用OM, SEM和中子衍射技术对微观组织和宏观织构进行了研究. 结果表明, 复合板材中Mg和Al层组织均随着循环次数的提高而细化; 在200 ℃时随着退火时间的增加, 晶粒逐渐均匀但没有明显长大. 累积叠轧过程中Mg层主要呈现出典型的轧制织构类型, Al层则表现出以轧制织构组分为主, 同时伴有剪切织构组分的混合织构类型. 对于3 cyc轧制的Mg/Al多层复合板材, 在200 ℃经不同时间退火后, Mg层依然为轧制织构类型, Al层为轧制织构与剪切织构组分混合. 随着累积叠轧循环道次的增加, 屈服强度和抗拉强度都逐渐上升.
关键词:
Mg/Al多层复合板
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累积叠轧
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体织构
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中子衍射
徐平光
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殷匠
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张书彦
金属学报
doi:10.11900/0412.1961.2014.00541
利用飞行时间法中子衍射对比研究了充氢与未充氢1250 MPa超高强度钢的拉伸变形行为与轴向晶格变形特征,并观察了断口区组织形貌与晶粒取向特征.在无加载条件下,充氢试样的轴向(110)与(200)面间距分别大于和小于未充氢试样的对应面间距,显示出四面体间隙中H原子的进入使轴向(110)面间距有所增加,同时内部应力的平衡作用使轴向(200)面间距有所减少.未充氢试样达到1250 MPa抗拉强度发生颈缩塑性断裂,而含有8.0×10-6可扩散氢的试样在分步加载至500 MPa时发生脆性断裂.中子衍射分析表明,未充氢试样在拉应力加载至500 MPa时均基本符合线弹性变形,但至700MPa时,轴向{200}晶粒比其余取向晶粒优先显示非线弹性变形,至800MPa时轴向{110}晶粒也出现非线弹性变形,轴向{200}晶粒优先产生微屈服现象,而轴向{211}晶粒仍然处于线弹性阶段;充氢试样在拉伸至300MPa时,轴向{110}晶粒出现非线弹性变形,至400MPa时轴向{200}晶粒也出现非线弹性变形,轴向{110}晶粒优先产生微屈服现象,轴向{211}晶粒仍处于线弹性阶段.断口剖面观察显示未充氢试样内形成明显的轴向<110>拉伸纤维织构,而氢脆试样内除了明显的晶界裂纹萌生,还有晶内裂纹扩展与局部晶体转动特征.基于不同取向晶粒的微屈服概念,解释了充氢导致轴向{110}晶粒优先微屈服而不是轴向{200}晶粒优先微屈服,同时以氢伴随微区塑性变形的方式发生脆性断裂.
关键词:
脆性断裂
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充氢
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微区塑性变形
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高强度低合金钢
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中子衍射
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晶格应变
李眉娟
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刘晓龙
,
刘蕴韬
,
郑明毅
,
王琛
,
陈东风
金属学报
doi:10.11900/0412.1961.2015.00286
以商业纯Mg和AAl050Al板材为初始材料,采用累积叠轧技术在室温下进行不同轧制道次变形制备了Mg/A1多层复合板材料,并对3 cyc轧制的Mg/Al多层复合板材料在200℃分别进行不同时间退火处理.利用OM,SEM和中子衍射技术对微观组织和宏观织构进行了研究.结果表明,复合板材中Mg和Al层组织均随着循环次数的提高而细化;在200℃时随着退火时间的增加,晶粒逐渐均匀但没有明显长大.累积叠轧过程中Mg层主要呈现出典型的轧制织构类型,Al层则表现出以轧制织构组分为主,同时佯有剪切织构组分的混合织构类型.对于3 cyc轧制的Mg/Al多层复合板材,在200℃经不同时间退火后,Mg层依然为轧制织构类型,Al层为轧制织构与剪切织构组分混合.随着累积叠轧循环道次的增加,屈服强度和抗拉强度都逐渐上升.
关键词:
Mg/Al多层复合板
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累积叠轧
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体织构
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中子衍射
