Z.M.Sun
,
H.Hashimoto
,
S.Sumi
,
Y.H.Park and T.Abe (Materials Engineering Division
,
Tohoku National Industrial Research Institute 4-2-1 Nigatake
,
Miyagino-ku
,
Sendai 983-8551
,
Japan) Z.H. Shan (Research Fellow of Science and Technology Agency of Japan STA)
金属学报(英文版)
Two intermetallic compounds of Ti-50at.% Al and Ti-48at.% Al-2at.% Cr were prepared with a mechanical alloying and pulse discharge sintering process. The as-sintered material showed a microstructure of equiaxed gamma grain with sub-micron size. Heat treatments in vacuum at different temperatures up to 1573K were conducted on the sintered materials. The microstructure of the material coarsened considerably after heat treatment at temperatures higher than 1523K. The mechanical properties of the as-sintered and the heat treated materials were measured at temperatures of up to 973K, with four-point bending tests. Experimental results indicated that the addition of Cr increased the fracture strength of the intermetallic compound at room temperature and at elevated temperatures as well. The bending fracture strength increased with increasing testing temperature up to about 873K and a decreasing followed up. Both fracture strength and fracture strain of the material were found to be improved by heat treatment.
关键词:
titanium aluminide
,
null
,
null
,
null
,
null
WADSWORTH Jeffrey and FLUSS Michael(Chemistry and Materials Science Directorate
,
Lawrence Livermore National Laboratory
,
Livermore
,
CA 94551)
金属学报(英文版)
The role of the National Laboratories is summarized from the era of post World War II to the present time. The U.S. federal government policy for the National Laboratories and its influence on their materials science infrastructure is reviewed with respect to .determining overall research strategies, various initiatives to interact with industry (especially in recent years),building facilities that serve the nation, and developing leading edge research in the materials sciences. Despite reductions in support for research in the U.S. in recent years, and uncertainties regarding the specific policies for Research &Development (R&D) in the U.S., there are strong roles for materials research at the National Laboratories. These roles will be centered on the abilities of the National Laboratories to field multidisciplinary teams, the use of unique cutting edge facilities, a focus on areas of strength within each of the labs,increased teaming and partnerships, and the selection of motivated research areas. It is hoped that such teaming opportunities will include new alliances with China, in a manner similar, perhaps, to those recently achieved between the U.S. and other countries.
关键词:
: U.S. Materials Science. U.S. National Laboratories and Facilities
,
null
FU Jian-xun
,
LI Jing-she
钢铁研究学报(英文版)
The broadening of slab was investigated on the basis of several industrial manufactures of continuous casting. The results show that slab broadening commonly exists in the process of continuous casting. It is found that there are few reports on it until now. In order to find out the reasons of slab broadening, we checked the effect of change of mold size, excepting technological parameters, conditions of soft reduction, and contraction of roll gap on slab broadening. Our examinations exclude the possibility of change of mold size, excepting technological parameters to be the causes of broadening of slab. The broadening of slab probably results from the static pressure of molten steel and the force from driving rolls. At the same time, online observations on three kinds of steel in the process of continuous casting reveal that the average objective ratio of slab broadening ranges from 1.27 % to 3.00 %, and even arrives at 4.4 %. In addition, the width of mold and formulas of calculating the broadening of slab was deduced.
关键词:
continuous casting;slab;broadening;industrial investigation
KEIZO HASHIMOTO(Advanced Technologies Research Laboratories Nippon Steel Corp.1618 Ida Nakahara-ku Kawasaki 211 JAPAN)
金属学报(英文版)
Gamma titanium aluminide (γ-TiAl)intermetallic compounds are spotlighted as lightweight heat-resistant materials, and have been investigated extensively to aiming commercial use.Fundamental approaches in which phase diagrams of Ti -Al -Cr and TiAl -Nb have been studied based on the experimental data and calculations , have been performed in the national project For industrial approach, ingot process and direct casting process have been developed to provide sheet form of TiAl. By these approaches, γ-TiAl base ,intermetallic compounds show a great possibility to apply in the variety of fields .However, a more detailed understanding of phase equilibrium in Ti-Al -X and the relationship between the mechanical properties and microstructure will be necessary
关键词:
: TITANIUM ALUMINIDE
,
null
,
null
,
null
,
null
Chinese Journal of Organic Chemistry
2,5-Dihydrazino-1,3,4-thiadiazole was prepared by 2,5-dimecapto-1,3,4-thiadiazole and hydrazine, and then the six novel different 2,5-bis(benzylidenehydrazino)-1,3,4-thiadiazole compounds were obtained by a condensation reaction of 2,5-dihydrazino-1,3,4-thiadiazole with substituted benzaldehyde and structurally confirmed by elemental analysis, IR, H-1 NMR and mass spectra. The result indicates that the six 2,5-bis(benzylidenehydrazino)-1,3,4-thiadiazole compounds are of definite inhibition against silver surface in corrosion jet fuel.
关键词:
2,5-dimercapto-1,3,4-thiadiazole;hydrazine;benzaldehyde;aldehyde-hydrazone;synthesis;anti-corrosion;derivatives
高嫒嫒
,
赵群星
,
陈龙
,
李涛
,
闫晓亮
液晶与显示
doi:10.3788/YJYXS20142904.0485
丁烯类液晶具有黏度小、熔点低、清亮点高、低温稳定性良好的优点,对改进混晶的性能有着显著作用,是一类具有广阔前景的液晶单体.本文经过对接、酰化、酯化反应得到2氟4溴1乙酸乙酯基联苯,与丙基苯硼酸偶联、还原、氯代得到4氯甲基-2′-氟-4″丙基-[1,1′,4′1″]三联苯,再与3-氯丙烯的格氏试剂偶联,共7步反应得到目标产物4-(3-烯)正丁基-2 ′氟-4″丙基-[1,1 ′,4 ′1″]三联苯,总收率为21.7％.最后对化合物进行了IR、H1NMR、GC-MS表征.
关键词:
丁烯类液晶
,
合成
,
4-(3-烯)正丁基-2′氟-4″丙基-[1,1 ′,4 ′1″]三联苯
Acta Physico-Chimica Sinica
The effect of thiourea(TU) on the corrosion behavior of bulk nanocrystallized and coarse grain industrial pure iron in.1 mol . L-1 HCl at room temperature was investigated, by means of electrochemical impedance spectroscopy (EIS). Bulk nanocrystallized industrial pure iron is less prone to get corrosive than its coarse grain counterpart in blank 1 mol . L-1 HCl at room temperature from the EIS fitting results. On the basis of the variation of impedance behaviors of bulk nanocrystallized and coarse grain industrial pure iron in the inhibitor-containing 1 mol . L-1 HCl solutions with the immersion time, an relationship between immersion time and Nyquist plot was established, for very short immersion time, namely, 5 min, an inductive loop appeared at different concentrations in the Nyquist plots of coarse industrial pure iron rod, but it did not appear in those of nanocrystallized industrial pure iron. A critical concentration of thiourea with the largest R,,(charge transfer resistance) in the complex impedance plane appeared for both samples.
关键词:
bulk nanocrystallized industrial pure iron;thiourea;inhibition;electrochemical;impedance spectroscopy (EIS);hydrochloridic solution;mild-steel;electrochemical techniques;derivatives;acid
