J.X. Zhang
,
D.M. Liu
,
Y.Q. Liu
,
M.L. Zhou
,
T.Y. Zuo
金属学报(英文版)
The mechanical properties of molybdenum wires doped with different contents of La2O3 were investigated systematically and the interaction between La2O3 particles with dislocations in Mo- La2O3 wires were observed by SEM and TEM. It is shown that Mo-La2O3 wires possess much higher tensile strength than the pure Mo. In wires the dislocation motion is strongly hindered by La2O3 particles, which remains up to much higher temperature. Moreover, a number of prismatic dislocation loops and hexagonal dislocation network have been formed in annealed Mo-La2O3 wires. The higher strength of Mo-La2O3 than the pure Mo is attributed to the La2O3 particles dispersion strengthening and dislocation strengthening.
关键词:
molybdenum
,
null
,
null
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
Materials Research Bulletin
Through analysis of the latest experimental results reported in the literature and obtained in our laboratory, we have extended our previous quantum confinement/luminescence center model for the photoluminescence mechanism of porous Si and of nanometer-silicon-particle-embedded Si oxide films (G.G. Qin and Y.Q. Jia, Solid State Commun. 86, 559 (1993)). We consider that there are three main types of competitive photoexcitation/photoemission processes and that the process in which photoexcitation occurs in the nanometer silicon particles (NSPs) while photoemission occurs in the luminescence centers (LCs) in the SiOx layers very close to the NSPs is usually the major one. We discuss under what conditions the other two types of processes will dominate. We believe that the extended quantum confinement/luminescence center model is a physical model that is suitable for the photoluminescence from silicon oxide films embedded with NSPs or nanometer Ge particles (NGPs), as well as from oxidized porous Si. (C) 1999 Elsevier Science Ltd.
关键词:
oxides;luminescence;defects;blue-light emission;visible luminescence;optical-properties;nanocrystals;mechanism;dependence;sio2-films;absorption;spectra;defects
