Y.Z. Yang
,
Y.H Luo
,
Q.S. Li
,
Y.L. Zhu
,
X.M. Ma
,
Y.D. Dong and Y.Z. Chuang(Department of Materials Science and Engineering
,
Guangdong University of Technology
,
Guangzhou510090
,
China)(Guangdong Educational College
,
Guangzhou 510084
,
China)(Department of Materials Science and Engineering
,
Shanghai University
,
Shanghai 200072
,
China)(Institute of Metal Research
,
The Chinese Academy of Sciences
,
Shenyang 110015
,
China)
金属学报(英文版)
The structural transformation in Fe-Cu powder induced by mechanically driven alloying has been monitored by the lattice constant measurements and Mossbauer spectroscopy. For the samples with Cu higher than 75at.% Mossbauer the spectra show a broad paramagnetic doublet; for samples with 50 and 60at.%Cu a new broad ferromagnetic sextet; for those with less than 30at.%Cu similar to those of α-Fe. The main peaks of the hyperfine field distribution significantly broaden and shift to a lower position with increasing Cu content due to the complex environments of iron atoms in the solid solutions and the reduction in the nearest neighbor Fe of a cental Fe atom, respectively. The saturation magnetization of Fe-Cu alloys monotonously decreases with Cu content. The complex composition dependence of coercive field for the milled samples is discussed with respect to the solid dissolution, grain size, interfacial state etc.. The increase of lattice constants with the solute content in the two terminal solid solutions has been explained by the volume-size factor theory or magnetovolume effect.
关键词:
mechanical alloying
,
null
,
null
,
null
Y.Z. Yang
,
Y.L. Zhu
,
Q.S. Li
,
X.M. Ma
,
Y.D. Dong and Y.Z. Chuang (Department of Materials Science and Engineering
,
Guangdong University of Technologyt Guangzhou 510090
,
China)(Depotment of Materials Science and Engineering
,
Shanghai University
,
Shanghai 200072
,
China)(Institute of Metal Research
,
The Chinese Academy of Sciences
,
Shenyang 110015
,
China)
金属学报(英文版)
Nanocrystalline supersaturated solid solutions (Sa in Fe) with Sn content less than 50 at. %,and FeSn2 and Fe1.3Sn intermetallic compounds have been prepared by mechanical alloying of Fe and Sn mixture powders with composition of Fe1-xSnx (x≤0.5).The atomic alloying the formation and microstructure, especially the coordination environments, of the resultant alloys have been studied by X-ray diffraction, 57Fe and 119Sn Mossbauer Spectroscopy and diffrrential scanning calorimetry. The Fe and Sn coordination environments and the composition dependence of the hyperfine parameters on the Fe and Sn content have been fully discussed with respect to the solid dissolution alloying, grain refinement, and distortion caused or induced by mechanical alloying.
关键词:
mechanical alloying
,
null
,
null
Y.Z. Yang
,
X.J. Bai
,
T.C. Kuang
金属学报(英文版)
The structure of bcc-Fe80 Cu2o solid solution produced by mechanical alloying of theelemental bcc-Fe and fcc-Cu powders has been studied using X-ray diffraction and theextended X-ray absorption fine structure (EXAFS) techniques. The disappearance ofelemental Fe and Cu X-ray diffraction (XRD) peaks and the presence of bcc structuralXRD peaks illustrate the formation of a nanocrystalline single-phase bcc-Fe80 Gu20solid solution. From the EXAFS results, the clear observation of Cu atoms taking onbcc coordination in the solid solution and Fe atoms remaining bcc structure furtherverifies the reality of atomic alloying between Fe and Cu atoms and the lattice changeof Cu from fcc to bcc. However, the supersaturated bcc solid solution is not chemicallyuniform, i.e., some regions are rich in Fe atoms and other regions rich in Cu atoms.
关键词:
mechanical alloying
,
null
,
null
,
null
何恩全
,
马文会
,
刘荣辉
,
于洁
,
戴永年
稀有金属
doi:10.3969/j.issn.0258-7076.2007.04.019
采用了甘氨酸-硝酸盐法制备了La0.7Sr0.3Cr0.5-yMn0.5-zCo(y+z)O3(y, z=0.1, 0.2)系列阳极材料.借助XRD, SEM对所制备的材料进行了物相和形貌分析.XRD表明利用GNP法制得的粉体在1350 ℃烧结5 h可以形成完整的钙钛矿相;SEM分析可知所得物料颗粒呈球状,尺寸约为1 μm,且没有团聚现象.同时,XRD显示La0.7Sr0.3Cr0.5Mn0.4Co0.1O3和La0.9Sr0.1Ga0.8Mg0.2O3电解质之间具有较好的化学相容性.采用直流四探针法测试了不同组成材料在250～800 ℃温度范围内在空气中的电导率,发现该系列材料在该温度段范围符合小极化子导电机制.另外,利用直流四探针法测试了La0.7Sr0.3Cr0.5Mn0.4Co0.1O3在不同还原气氛下的电导率,在CH4和H2气氛中,La0.7Sr0.3Cr0.5Mn0.4Co0.1O3最大电导率分别达到了4.5和0.42 S·cm-1.
关键词:
钙钛矿
,
阳极
,
电导率
黄曼青
,
周全
,
刘峰
,
黄金角
材料导报
doi:10.11896/j.issn.1005-023X.2016.22.010
研究了0~1.4 T的直流磁场对陶瓷型铸造 Mg-Y-Cu-Zr 合金结晶取向和力学性能的影响。结果表明直流磁场对合金的初生相没有明显影响，但磁场强度大于1.12 T时，合金第二相的分布变得不连续。当磁场强度小于0.84 T时，α-Mg在(002)面的衍射峰逐渐增强，但变化不明显；当磁场强度大于0.84 T 时，α-Mg 基体在(002)、(101)面的衍射峰强度明显减弱，而在(100)晶面衍射峰强度有所增强。磁场处理后，合金的综合力学性能得到了改善；当磁场强度为1.4 T 时，其抗拉强度和伸长率最高，分别为237 MPa 和8.5%，较无磁场处理时分别提高了38.6%和33.4%。
关键词:
直流磁场
,
Mg-Y-Cu-Zr合金
,
结晶取向
,
力学性能
Ying Liy Changzhen Wang Zhongli Zhang Jiangxin Wang
材料科学技术（英文）
The steel contains a small amount of hydrogen which will escape during the heat treatment. The hydrogen pressure in 16MnRE steel was investigated with a hydrogen sensor, which used SrCe0:95Yb0:05O3-α proton conductor as a solid electrolyte, YHx+YH2-z as a solid state reference electrode and Ni wire as electrode constructing a hydrogen concentration cell, shown as Ni|YHx+YH2-z |SrCe0:95Yb0:05O3-α |[H]steel |Ni. The response time of sensor is less than 10 s. The relational expression of hydrogen partial pressure with temperatures was determined using two shape proton conductors. The results showed the regularity in experimental temperature range, and the hydrogen partial pressure increased as its temperature was raised.
关键词:
Hydrogen sensor
,
Proton conductor
,
Solid electrolyte
王晓旭
,
陈利
材料工程
doi:10.3969/j.issn.1001-4381.2011.11.001
通过单根Z-pin从复合材料层合板中拔出的试验方法,测试了Z-pin的拔出强度,计算了Z-pin的临界埋入深度,并引入抗拉强度利用率概念来表征Z-pin的抗拉强度在拔出过程中的利用程度.结果表明,直径0.50mm和0.28mm的Z-pin临界埋入深度分别约为5.1mm和3.1mm.当Z-pin的埋入深度小于临界埋入深度时,Z-pin从层板中拔出；Z-pin拔出强度与埋入深度成正比,与Z-pin的直径成反比；当Z-pin的埋入深度大于临界埋入深度时,Z-pin发生断裂,Z-pin的抗拉强度利用率达到100％.最后提出了提高抗拉强度利用率的建议.
关键词:
Z-pin
,
拔出强度
,
复合材料
,
拔出试验
,
抗拉强度
