C.S.Hu1
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2) and Y.X.Gu3) 1) Department of Mechanical Engineering
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Fushun Petroleum Institute
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Fushun 113001
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China 2) State Key Laboratory for Corrosion and Protection
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Institute of Corrosion and Protection of Metal
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The Chi nese Academy of Science
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Shenyang 110015
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China 3) Departmentof Materials Scienceand Engineering
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Shenyang Polytechnic University
,
Shenyang 110023
,
China
金属学报(英文版)
Weldingthermalcyclicsimulated techniquesisemployed in thestudy. By meansof analysismetalloscope, fracture morphology and impact toughness test of the sample, the effect ofweldingthermalcycle peak temperature and dualthermal cycle on the micro structure and toughnessoflow alloy high strength steel HQ100 isinvestigated.Inner fine martensitic andbainitic microstrctureisobservedby TEM.Theresultsshow that withtheincreaseof peaktem perature, grain sizesbecomelarger,theimpacttoughness drop down .Ifthermalcycleisim posed twiceand dualthermalcyclicpeaktemperatureis1275 ℃+ 750 ℃,theimpacttoughnessisatthelowest value.Alsotheimpacttoughnessagrees withthefracture morphology.
关键词:
thermalcycle
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null
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null
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null
Xianran XING
,
Zhiyu QIAO
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Wenxia YUAN and Shoukun WEI (University of Science and Technology Beijing
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Beijing
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100083
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China)(To whom correspondence should be addressed)Xiaolong CHEN
,
Guanghui RAO and Jingkui LIANG (Institute of Physics
,
Chinese Academy o
材料科学技术（英文）
By X-ray powder diffraction technique and oxygen content analysis, a solid solution Sm1+xBa2-xCu3Oy has been determined in the range 0≤x≤0.4. When x<0.25. the Sm1+xBa2-xCu3Oy presents orthorhombic symmetry, and the orthorhombic-tetragonaJ transition ocCurs at x = 0.25. With the increase of x, TC decreases and finally breaks. The correlation between ox ygen content and phase structure at different quench temperatures related to Sm Ba2Cu3Oy has been investigated as well
关键词:
Applied Physics Letters
The effect of nonmagnetic Y partial substitution at the Dy site in Dy(1-x)Y(x)MnO(3) up to x=0.2 on magnetism, specific heat, and ferroelectricity is investigated, which resulted in a preliminary multiferroic phase diagram. It is revealed that the Y partial substitution suppresses the Dy-spin ordering point (T(Dy)) and ferroelectric ordering point (T(FE)) but enhances the Mn-spin ordering point (T(N)). The interaction between the spins of Dy and Mn is remarkably affected by Y substitution. The measured electrical polarization depends on the Y substitution in a complex way because the ferroelectricity is sensitive to the interaction between the spins of Dy and Mn. (c) 2011 American Institute of Physics. [doi: 10.1063/1.3536506]
关键词:
ferroelectricity;polarization
罗广圣
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李小怡
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周正有
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刘光华
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熊惟皓
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吴小山
中国有色金属学报
采用固相反应法制备La(1.x)2/3Ca1/3MnO3(x=0.0,0.04)和(La0.7Y0.3)2/3Ca1/3MnO3系列样品,测量不同温度下的磁化强度-磁场曲线,计算样品的磁熵变,研究La空位掺杂和Y3+离子掺杂对磁热效应的影响.结果表明,La空位掺杂(x=0.04)的样品在居里温度附近磁熵变最大值为6.22 J/(kg.K),这比La2/3Ca1/3MnO3磁熵变最大值(6.26 J/(kg.K))稍有降低;而Y3+离子掺杂的样品在温度60 K时和磁场强度2 T下,其磁熵变最大值为0.568 J/(kg.K),并且磁熵变随温度变化有继续增大的趋势.这表明(La0.7Y0.3)2/3Ca1/3MnO3可以作为一定温区的磁致冷材料.
关键词:
(La(1-x-y)Yy)2/3Ca1/3MnO3化合物
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固相反应
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磁热效应
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磁熵变
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空位掺杂
Applied Physics a-Materials Science & Processing
The Pr(1+x)Ba(2-x)Cu(3)O(7+/-delta) solid solution was investigated by means of X-ray powder diffraction combined with Rietveld analysis. A Pr123 single phase could be synthesized under Pr-rich conditions by sintering at 950 degreesC in air. The solubility range of Pr(1+x)Ba(2-x)Cu(3)O(7+/-delta) solid solution is 0.08 less than or equal to x less than or equal to 0.80. The structure of Pr(1+x)Ba(2-x)Cu(3)O(7+/-delta) for 0.08 less than or equal to x less than or equal to 0.30 is orthorhombic. The structure transforms into tetragonal for 0.30 less than or equal to x less than or equal to 0.80. To form the Pr123 single phase, the Ba sites in the Pr123 structure must have partial Pr ions, and the least amount is x = 0.08. Ba ions cannot occupy the sites of Pr ions. In the Pr123 structure, Ca ions can replace Pr ions; the highest value is x = 0.4 in the PrBa(2-x)Ca(x)Cu(3)O(7+/-delta) system under our experimental conditions. However, Ca ions cannot replace B a ions. The ionic radius plays a more important role than the chemical properties in the substitution between Pr, Ba and Ca ions in the Pr123 structure.
关键词:
cu-o system;approximately 950-degrees-c;superconductivity;diagram;pr;growth;nd;prba2cu3o7-delta;praseodymium;property
LI Ying
,
WANG Xiaotian
,
JIN Zhihao Xi'an Jiaotong University
,
Xi'an
,
China SHl Guoshun Beijing Measuring and Analysing Center.Beijing
,
China
金属学报(英文版)
The effect of subzero treatment on the microstructure and mechanical properites of Y_2O_3- ZrO_2 ceramic have been investigated by TEM,X-ray diffraction and test of mechanical properties.It was shown that the microstructre of 3Y-PSZ after subzero treatment by liquid nitrogen exhibits very long and parallel laths of m-phase and some microcracks around the larger and finer lath of m-phase may be discovered.Suitable subzero treatment can improve the strength and toughness of Y-PSZ efficiently because of decreasing the stability of t-phase and incresing the amount of t-m transformation when exerting a stress.However,when the time of subzero treatment exceeds,the over aging effect may arise.which can decrease the strength and toughness of the material.
关键词:
Y_2O_3-ZrO_2 partially stabilized zirconia(PSZ)
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null
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null
Materials Science and Technology
The mechanical properties of 20 vol.-%SiC whisker reinforced ZrO2-Y2O3 composites containing 2 and 6 mol-% Y2O3 were measured at room temperature and the fracture surface was examined. The results indicate that the mechanical behaviour of the composites is strongly influenced by the Y2O3 content. The magnitude of the enhancement ofthe toughness in composites containing 2 mol.-% Y2O3 compared with unreinforced ZrO2-Y2O3 matrix is larger than that for the composites containing 6 mol-% Y2O3. Crack propagation modes were characterised by crack deflection, whisker bridging, and whisker pullout. High resolution electron microscopic observations show that in composites containing 2 mol.-% Y2O3 the whiskers are directly bonded to the matrix. However; in composites containing 6 mol.-%Y2O3 there is always a thick amorphous layer at the interface, indicating that the high Y2O3 content has promoted the formation of interfacial amorphous layers. These interfacial amorphous layers strengthen the interfacial bonding, resulting in a composite with a low fracture toughness.
关键词:
Physica B-Condensed Matter
The magnetic properties and magnetocaloric effect of Tb(1-x)Y(x)CoC(2) (x = 0, 0.1, 0.2, 0.3, 0.4) compounds have been investigated systematically. All the compounds undergo second-order transitions from paramagnetic to ferromagnetic states without thermal and magnetic hysteresis. With increasing Y content from 0 to 0.4, the Curie temperatures decrease nearly linearly from 28 to 18 K. The nature of the second-order phase transitions can be confirmed by Arrott plots. For Tb(0.6)Y(0.4)CoC(2) compound, the maximum value of the magnetic entropy change -Delta S(M) at 20 K is 9.35 J kg(-1) K(-1) for an external field change of 5T (5.14 J kg(-1) K(-1) for 2T). The large reversible magnetic entropy change makes Tb(0.6)Y(04)CoC(2) compound an attractive candidate for the application at hydrogen liquefaction temperature. (C) 2010 Elsevier B.V. All rights reserved.
关键词:
Curie temperature;Magnetocaloric effect;Magnetic properties;ac susceptibility
