材料期刊网

ORIENTATION VARIANT SELECTION AND ITS EFFECTING FACTORS IN TITANIUM SHEET

Z.S. Zhu , N.P.Chen , J.L. Gu and M.G. Yan(1)Institute of Aeronautical Materials , P.O. Box 8115 , Beijing 100095 , China 2)Department of Materials Science and Engineering , Tsinghua University , Beijing 100084 , China Manuscript received 26 August 1996)

金属学报(英文版)

By means of crystallite orientation distribution function (ODF) analysis, the influence on orientation variant selection of cold rolling reductions, recrystallization annealing and cooling rates during α→β→α cyclic phase transformation treatments in cold rolled titanium sheet has been investigated. The results show that, cold rolling reduction and annealing treatment both have a great effect on the formation of phase transformation textures.No variant selection occurs in cold rolled and recrystallization annealed titanium sheet which resulte in a more randomly distributed texture.The phase transformation texture formed α→β→α transformation is inherited after 3 cycles of α→β→α phase transformation. The cooling rates during phase transformation have little effect on orientation variant selection.

关键词: :texture , null , null , null , null

SHALLOW DONOR IMPURITY IN A QUANTUM BOX - EFFECTS OF IMAGE POTENTIAL

Solid State Communications

Considering the image potential, we calculate the binding energies of a shallow donor impurity placed on the centre of a quantum box using the variational approach. The results we have obtained show that there is a great difference of the effects of image potential between the cases including impurity ion image potential and including the image potentials of impurity ion and electron simultaneously. The results also show that the image potential is important, especially when the dimensions of quantum box become small.

关键词: well;gaas-ga1-xalxas;states

EFFECTS OF SPECIFIED BLANK SIZE ON BODY WRINKLING DURING HYDRODYNAMIC DEEP DRAWING OF TAPERED RECTANGULAR BOX

L. H. Lang , D. C. Kang , S. H. Zhang , Z. R. Wang , S. J. Yuan , K. B. Nielsen and J. Dancket 1) Department of Materials Engineering , Harbin Institute of Technology , Harbin 150001 , China 2) Aalberg University , Denmark

金属学报(英文版)

In this paper, the forming features of tapered rectangular box during hydrodynamic deep drawing are studied by means of FEM.The effect rules of square blank corner corner amount on body wrinkling are recognized and corresponding methods are discussed. At last, the results of FEM are verified by experi- ment.

关键词: sheet metal forming , null , null

Effect of Variable Blank Holder Force on Rectangular Box Drawing Process of Hot-galvanized sheet Steel

Qunqiang FU

材料科学技术（英文）

At first, a series of finite element method (FEM) simulation tests were used to find the critical forming conditions of hot-galvanized sheet steel during the rectangular box drawing processing when constant blank holder forces were applied. According the test results, the reasonable alteration scope of initial variable blank holder force (VBHF) was as 1.9~2.3 T. Then, based on the test productions of blank holder force, 12 typical VBHF curves were applied to perform the simulation tests by the simulation software of DYNAFORM. The simulation test results showed that VBHF had great effects on drawing formability of hot-galvanized sheet steel during the rectangular box drawing. However, the different VBHF curves were applied to control the whole drawing and it would get great different effects. At the same tine, the VBHF had great effects on the maximum thick thinning ratio, but had little effect on the maximum thick incrassation ratio. So, reasonable application of the VBHF would greatly decrease the fractures. When the VBHF profile is taken as curve L, the best effect of drawing formability could be obtained. When curve I is used, contrary effect could be gotten. The other types of curves would cause effects between above two types of VBHF curves. Finally, the actual tests were applied to check the validity of the FEM simulation tests. The results show that the FEM simulation tests are good ways for predicting and optimizing the VBHF.

关键词: Drawing process , 变压边力 , 热镀锌钢板

Phase relations in the system La2O3-B2O3-P2O5

Journal of Alloys and Compounds

The subsolidus phase relations in the system La2O3-B2O3-P2O5 were investigated. The system can be divided into 12 three-phase regions. There are nine binary compounds and one ternary compound in this system. The ternary compound La7O6(BO3)(PO4)(2) has a monoclinic structure, space groups P2(1)/n, with lattice constants a = 7.0172 Angstrom, b = 17.9125 Angstrom, c = 12.6500 Angstrom, beta = 97.516 degrees, V = 1576.39 Angstrom(3), and Z = 4.

关键词: La2O3-B-3-B2O3-P2O5 system;phase relations;ternary compounds

p-Al2O3的水化特性研究

陈玮 , 姚长江 , 尹周澜 , 刘新红

耐火材料 doi:10.3969/j.issn.1001-1935.2008.04.009

分别对反应前后的p-Al2O3进行XRD及SEM分析,确定反应前后Al2O3的物相及显微结构变化;测定加入添加剂前后浆体温度与时间的关系,从而确定添加剂对p-Al2O3水化速度的影响;测定加入添加剂前后浆体的黏度变化,从而测定出添加剂对p-Al2O3水化过程的影响.结果表明:1)p-Al2O3属于无定形态;2)在没有添加剂的情况下,p-Al2O3的水化速率很快,同时释放出大量热量,水化产物主要是一水软铝石、三水铝石和拜耳石;3)加入碳酸钠及六偏磷酸钠的混合物为添加剂后,p-Al2O3的水化速率显著降低,释放出的热量显著降低,水化产物主要是一水软铝石.

关键词: p - 氧化铝 , 水化硬化 , 不定形耐火材料 , 结合剂

Subsolidus phase relations in the system BaO-B2O3-P2O5

Journal of Alloys and Compounds

The subsolidus phase relations in the system BaO-B2O3-P2O5 were determined. The system can be divided into 16 three-phase regions. There are nine binary compounds and three ternary compounds in this system. (C) 1997 Elsevier Science S.A.

关键词: ternary oxide system;alkaline earth borophosphates;crystal structure;crystal-structure;borate

Structure and Mechanical Properties of NiPNano Al2O3 Composite Coatings Synthesized by Electroless Plating

ZHOU Guanghong , DING Hongyan , ZHOU Fei , ZHANG Yue

钢铁研究学报(英文版)

NiPnano Al2O3 composite coatings were deposited by electroless plating, and their microstructures were observed by SEM (scanning electron microscope). The microhardness and the wear resistance of the NiPnano Al2O3 composite coatings were measured using microhardness tester and blockonring tribometer, respectively, and the comparison with those of NiP coatings or NiPmicro Al2O3 coating was given. The influences of aging temperature on their hardness and wear resistance were analyzed. The results showed that the nano Al2O3 particles were distributed uniformly in the NiPAl2O3 coatings. Among three kinds of NiP based coatings, the hardness and wear resistance of NiPnano Al2O3 coatings were largest, and the maximum values could be obtained at 400 ℃. This indicated that the precipitation of nano Al2O3 particles would improve the hardness and wear resistance of the NiP coatings.

关键词: composite coating;nano Al2O3;aging treatment;mechanical property

FeO-Fe_2O_3-CaO-P_2O_5渣系的密度

吴鼎芬

金属学报

用最大气泡法和秤重法分别地测定了液态和固态的FeO-Fe_2O_3-P_2O_5和CaO-P_2O_5渣系的密度。密度随系统中FeO+Fe_2O_3或CaO浓度的增加而升高。把实验结果结合本文作者以前研究过的FeO-Fe_2O_3-CaO系的密度值并外插到纯FeO处,得FeO在1400℃时密度应为4.7±0.15克/厘米~3,在25℃为5.85克/厘米~3。把4.7克/厘米~3作为FeO在1400℃时的密度,校正了本文作者以前导出的一个计算工业炉渣密度的半经验公式。 此外,根据研究结果,还讨论了分层渣系FeO-Fe_2O_3-CaO-P_2O_5的密度。

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Superplasticity in an aluminum alloy 6061/Al(2)O(3)p composite

Lihong HAN , Jitai NIU , Darning JIANG , Tsunernichi Imai

材料科学技术（英文）

The superplasticity of an Al(2)O(3)p/6061Al composite, fabricated by powder metallurgy techniques, has been investigated. Instead of any special thermomechanical processing or hot rolling, simple hot extrusion has been employed to obtain a fine grained structure before superplastic testing. Superplastic tensile tests were performed at strain rates ranging from 10(-2) to 10(-4) s(-1) and at temperatures from 833 to 893 K. A maximum elongation of 200% was achieved at a temperature of 853 K and an initial strain rate of 1.67x10(-3) s(-1). The highest value obtained for the strain rate sensitivity index (m) was 0.32. Differential scanning calorimeter was used to ascertain the possibility of any partial melting in the vicinity of optimum superplastic temperature. These results suggested that no liquid phase existed where maximum elongation was achieved and deformation took place entirely in the solid state.

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