Y.Q. Chang
材料科学技术（英文）
Co doped ZnO nanowires with different Co contents have been fabricated by a chemical vapor deposition method. X-ray diffraction results show that all the samples are of single phase and crystallize in wurtzite ZnO structure. The lattice parameter a increases with increasing Co content, while the parameter c has no obvious change with increasing Co. Raman spectra show that the nonpolar E2(High) mode becomes broad and weak with the doping of Co, which indicates that the incorporation of Co causes structural disorder in the crystalline columnar ZnO lattice. The photoluminescence spectra exhibit that the position of the ultraviolet emission shifts to short wavelength and the intensity decreases with increasing Co. The green emission is affected by
two contrary factors. It is increased by the introduced defects, but suppressed by the interaction between Co doping and native defects and the later affects it more significantly.
关键词:
Co doped ZnO nanowires
Y.Q. Chang
材料科学技术（英文）
Large-scale flower-shaped Mn doped ZnO nanostructures have been grown on silicon substrates by simple thermal evaporation at atmospheric pressure. The flower-shaped nanostructure makes up of many nanorods, which are rooted in one center. Analysis of X-ray diffraction, high-resolution transmission electron microscopy and Raman spectra results reveal that the products are of single phase with wurtzite structure. Elemental mapping results show that no impurity clusters exist in the doped materials. The photoluminescence spectra demonstrate that many oxygen vacancies exist in the doped materials, and the crystal quality is improved and the content of oxygen vacancies is decreased by annealing treatment. The flower-shaped Mn doped ZnO nanostructures exhibit ferromagnetic ordering above room temperature, and its magnetization is decreased by the annealing treatment, which indicates that the magnetic behavior of the doped materials may be related to the interaction between Mn doping and the oxygen vacancies.
关键词:
Mn doped ZnO nanomaterials
Y.Q. Chang
材料科学技术（英文）
Large-scale flower-shaped Mn doped ZnO nanostructures have been grown on silicon substrates by simple thermal evaporation at atmospheric pressure. The flower-shaped nanostructure makes up of many nanorods, which are rooted in one center. Analysis of X-ray diffraction, high-resolution transmission electron microscopy and Raman spectra results reveal that the products are of single phase with wurtzite structure. Elemental mapping results show that no impurity clusters exist in the doped materials. The photoluminescence spectra demonstrate that many oxygen vacancies exist in the doped materials, and the crystal quality is improved and the content of oxygen vacancies is decreased by annealing treatment. The flower-shaped Mn doped ZnO nanostructures exhibit ferromagnetic ordering above room temperature, and its magnetization is decreased by the annealing treatment, which indicates that the magnetic behavior of the doped materials may be related to the interaction between Mn doping and the oxygen vacancies.
关键词:
Mn doped ZnO nanomaterials
余宏伟
,
王世森
,
王孝东
,
洪君
物理测试
针对鄂钢轧制的部分宽厚板表面出现结疤现象,应用金相显微镜、扫描电镜和能谱分析仪对Q345q热轧态钢板表面疤状物形态和成分进行观察,对形成原因进行分析并提出改进措施。结果表明：疤状缺陷为块状的非金属夹杂/渣,并在钢板表面形成凹坑,其成分为含有Si、Ti、Al、Ca、Mg的氧化物或硅酸盐、铝酸盐等,其主要为炼钢过程中的脱氧产物和合金的氧化产物。因此在生产过程中,通过去除钢水中夹杂物和清理铸坯等,减少非金属夹杂/渣,以提高钢板表面质量。
关键词:
Q345q
,
疤状缺陷
,
钢板
,
非金属夹杂
,
非金属夹渣
WANG Lei
,
GAO Cai-ru
钢铁研究学报(英文版)
Thermal mechanical control processing (TMCP), the combination of controlled rolling and controlled cooling, provides a powerful means of developing high-strength low alloy (HSLA) steels by intensive microstructural control. In the present investigation, the effects of TMCP parameters, consisting of the finish cooling temperature and the start rolling temperature in non-recrystallization region, on the final microstructure and mechanical properties of Q460q steel have been studied by tensile, Charpy impact tests, optical microscopy. The TMCP parameters for Q460q steel have been optimized by laboratory experiments. And the microstructure and properties of industrial product were coincident with the results of laboratory experiments.
关键词:
;TMCP;mechanical properties;M/A constituent;Q460q steel
王娟
,
李亚江
,
马海军
金属学报
采用扫描电镜(SEM)、能谱分析(EDS)、X射线衍射(XRD)和电子探针(EPMA)对Fe3Al/Q235扩散焊界面的析出相形貌进行观察和成分测定，研究微观析出相的形成以及工艺参数(T, t , p)的影响. 结果表明， Fe3Al/Q235扩散焊界面靠近Fe3Al一侧形成FeAl(Cr)析出相，是引起扩散焊接头脆性断裂的关键. 扩散焊温度T、保温时间t与析出相区宽度y符合抛物线规律: y2=3.5 (t-t0)exp[-5.6×104/(RT)]. 在降低加热温度和保温时间的条件下，增加焊接压力可促进Fe3Al/Q235界面原子的扩散，避免脆性析出相的形成，保证Fe3Al/Q235扩散焊接头的性能.
关键词:
Fe3Al合金
,
steel Q235
,
diffusion bonding
王娟
,
李亚江
,
马海军
金属学报
doi:10.3321/j.issn:0412-1961.2005.09.017
采用扫描电镜(SEM)、能谱分析(EDS)、X射线衍射(XRD)和电子探针(EPMA)对Fe3Al/Q235扩散焊界面的析出相形貌进行观察和成分测定,研究微观析出相的形成以及工艺参数(T,t,p)的影响.结果表明,Fe3Al/Q235扩散焊界面靠近Fe3Al一侧形成FeAl(Cr)析出相,是引起扩散焊接头脆性断裂的关键.扩散焊温度T、保温时间t与析出相区宽度y符合抛物线规律:y2=3.5(t-t0)exp[-5.6×104/(RT)].在降低加热温度和保温时间的条件下,增加焊接压力可促进Fe3Al/Q235界面原子的扩散,避免脆性析出相的形成,保证Fe3Al/Q235扩散焊接头的性能.
关键词:
Fe3Al合金
,
Q235钢
,
扩散焊
,
析出相
