黄懋容
,
殷定贞
,
曹玔
,
张玉苓
金属学报
<正> 在Co-Ga二元系中,β相的理想成分CoGa在室温的单相均匀范围为36.3—59.8at.-％Ga,它属于立方晶系的CsCl型结构,其点阵常数随Ga成分而变化,在接近理想成分的48at.-％Ga处有一最大值。在富Co端,为替代式固溶体。因为Co原子半径比Ga小,所以可以用原子半径大小来解释其实验现象。但在理想成分的富Ga一端,如果也属于替代式固溶体,则随着Ga含量的增加,点阵常数应增加,但实验的结果与此相反,因此文
关键词:
Co-Ga二元系
,
β-phase
,
positron annihilation
,
solid solution
赵飞
,
冯修吉
,
龙世宗
,
孙文华
,
王少阶
,
张才国
材料研究学报
对水泥矿物之一β-C_2S 的粉磨过程进行了摩擦化学研究,用X 射线微观应力测定法和正电子湮没技术(PAT)测定了粉磨过程中β-C_2S 晶格畸变和结构缺陷的变化,从形变的微观机制对测试结果进行了探讨。测定了不同粉磨时间样品的比表面积,粒径分布和水化放热速率,解释了不同大小颗粒水化活性差异的原因。
关键词:
粉磨
,
tribochemistry
,
microstress
,
positron annihilation
,
hydraulic activity
DENG Wen XIONG Liangyue LONG Qiwei Institute of Metal Research
,
International Centre for Materials Physics
,
Academia Sinica
,
Shenyang
,
China Associate Professor
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
China
金属学报(英文版)
The recovery recrystallization of 3 deformed Ni-Cr-Co superalloys with different Co con- tents has been studied using positron annihilation technique and TEM.The alloys with low Co content have more defects occurred than ones with high Co content,and the former may be faster in dislocation recovery than the latter.Thus,the apparent activation energy of recrystallization increases with the increase of their Co content in alloys.The relationship be- tween apparent activation energy and stacking fault energy together with their effect on re- covery were also discussed.
关键词:
positron annihilation
,
null
,
null
,
null
ZHANG Hong Shanghai Institute of Metallurgy
,
Academia Sinica
,
Shanghai
,
China
金属学报(英文版)
Effects of isochronal annealing on the positron annihilation of glassy Bi_(1.6) Pb_(0.4) Sr_(1.9)Ca_2 Cu_(3.1)O_y(BPSCCO)have been reported.It is shown that the crystallization influences obviously the positron annihilation characteristics of BPSCCO.A maximum is found in the region of crystallization temperature in curves of mean lifetime and peak/wing ratio, one of Doppler Iineshape parameter,with annealing temperature;the bulk lifetime of positron annihilation in the glassy state is longer than that in the crystalline one.Positron annihilation spectroscopy could be used for studying structure of glassy BPSCCO and its change with heat treatment.
关键词:
Bi oxide superconductor
,
null
,
null
,
null
,
null
DENG Wen XIONG Liangyue LONG Qiwei International Centre for Materials Physics
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
ChinaWANG Shuhe GUO Jianting Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
China Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
China
金属学报(英文版)
The behuviour of B atoms added to mono-and poly-crystalline Ni_3AI alloys has been investi- gated hy positron annihilation technique(PA T).If the additive of B was less than 1.37 at-%, some of B atoms solid-solutioned interstitially into matrix and distorted the lattice,thus the lifetime (τ) of positron (e~+) Or matrix dilated:the others of them segregated on vacancy-like defects and formed "filling effect",thus the mean lifetime (τ)and S parameters decreased.If B added was increased up to 2.22 at-%,more defects having larger free volume were induced by horide eutectic occurred along grain boundaries and grain interior,thus the τ in vacancy-like defects.τ and S parameters increased remarkably.
关键词:
Ni_3Al
,
null
,
null
,
null
PANG Dexing WANG Jingtang DING Bingzhe LI Zhixian Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
China WANG Jingtang
,
Professor
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
China
金属学报(英文版)
The glass transition in amorphous semi-conducting Se has been studied by DSC thermal ana- lysis,infrared absorption spectra and positron annihilation measurements.The results show that the glas transition seems to be reasonably explained from the viewpoints of MDS model and valence alternation pair theory proposed by Mott,Kaster et al.,respectively.
关键词:
amorphous Se
,
null
,
null
,
null
邓文
,
祝莹莹
,
周银娥
,
黄宇阳
,
曹名洲
,
熊良钺
稀有金属材料与工程
测量了Ti50Al50,Ti50Al48V2,Ti50Al48Ag2合金和充分退火的Ti,Al,Ag,V金属的正电子寿命谱,利用正电子寿命参数分别计算了合金基体和缺陷态的自由电子密度.TiAl合金的脆性与其基体和晶界缺陷处的自由电子密度较低有关.在富Ti的TiAl合金中加入V,V原子比Al和Ti原子能提供较多的自由电子参与形成金属键,因而提高了合金基体和晶界缺陷处的自由电子密度;在TiAl合金中加入Ag也有类似的效应.在TiAl合金中加入V和Ag,有利于提高合金的韧性.
关键词:
TiAl合金
,
电子密度
,
缺陷
,
正电子湮没
刘文斌
,
李书瑞
,
罗毅
材料热处理学报
利用离子辐照模拟中子辐照效应技术对AP1000安全壳用钢SA738Gr.B进行了高能氢离子辐照,采用透射电镜、聚焦离子束原位技术和正电子湮没技术,研究SA738Gr.B钢(两种热处理状态:淬火+回火态、淬火+回火+消除应力热处理(SR)态)经过高能氢离子辐照的辐照损伤行为.结果表明,在比较明显的辐照剂量下(0.2、0.5和1.0 dpa),钢基体中未观察到气泡、空位团等.两种样品的正电子湮没的寿命变化不大,说明这两种样品在试验所设计的辐照剂量下的微观缺陷变化不太明显.在位移损伤量为0.2 ～1.0 dpa的高能氢离子辐照下,两种热处理状态的SA738Gr.B/SA738Gr.B(SR)样品均具有良好的抗辐照肿胀能力.其中,在辐照剂量较大(0.5和1 dpa)时,SA738Gr.B样品的正电子寿命长于SA738Gr.B(SR),即SA738Gr.B样品的空位数量比SA738Gr.B(SR)更多,因此SA738Gr.B(SR)钢抗辐照性能更好.
关键词:
SA738Gr.B
,
消除应力热处理
,
离子辐照
,
正电子湮没
邓文
,
熊良钺
,
龙期威
金属学报
用正电子湮没技术及透射电镜研究了三种不同Co含量的 Ni-Cr-Co高温合金经室温形变后的回复再结晶过程.结果表明,在相同的形变量下,Co含量低的合金比 Co含量高的合金产生的缺陷多;在回复过程中,Co含量低的合金其位错回复比Co含量高的合金快,而且合金的表观再结晶激活能随Co含量的增加而增加.讨论了Co含量,表观再结晶激活能和层错能之间的关系以及它们对回复过程的影响。
关键词:
正电子湮没
,
stacking fault
,
apparent activation energy
,
recrystallization
